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We are able to perform the annual inspection for your license to store and dispense Petroleum. We are members of the of the A.P.E.A (association for petroleum and explosives administration) and the I.E.T (institution of engineering and technology).
Inspection of workplace storage and dispensing of petroleum spirit and liaison with petroleum licensing authorities
Dangerous Substances and Explosive Atmospheres Regulations 2002 SI 2002/2776
Background:-

1 Prior to DSEAR the storage of petroleum spirit at non-major hazard sites was regulated in most cases by PLAs under the Petroleum Consolidation Act 1928 (PCA) and subsidiary legislation. PLAs are mainly local authorities and the role is normally assigned to the fire authority or trading standards department. However, some authorities have allocated petroleum enforcement to Environmental Health Officers.

2 At sites where PLAs had no petrol licensing duties there is no change in the enforcement arrangements. Such sites comprise MoD sites and those subject to the Control of Major Accident Hazards Regulations (COMAH) and the Notification of Installations Handling Hazardous Substances Regulations (NIHHS).
Changes introduced by DSEAR

3 DSEAR amended the PCA (Enforcement) Regulations 1979 to enable the changes below.

4 The changes are:

removal of licensing controls under the PCA for all activities subject to DSEAR except for any activity relating to fuelling motor vehicles, ships* and aircraft (referred to in this OC as 'motor vehicles, etc.') with petroleum spirit from a storage tank;
for activities relating to fuelling motor vehicles, etc DSEAR applies as well as PCA. PLAs will enforce DSEAR in relation to such dispensing of petrol and the associated bulk storage; and
regulation of the storage and dispensing of petroleum spirit which is not associated with fuelling motor vehicles, etc. now comes under DSEAR and enforcement responsibility has been allocated to HSE/LA Environmental Health Departments (EHDs).

*NB: Ships are defined to include every type of vessel used in navigation propelled by an internal combustion engine.

5 Some examples to illustrate the above situations are given in the table at the Appendix. The examples are not exhaustive.

More information on some of the examples in the appendix is given in Dangerous substances and explosives atmospheres regulations

6 Where both DSEAR and PCA apply, PLAs will apply the petrol licensing conditions under the umbrella of the general legislative provisions in DSEAR. DSEAR provide a comprehensive framework for controlling dangerous substances of all types including petrol and require employers to:

assess the risks;

  1. take specific protection and prevention measures;
  2. establish emergency procedures; and provide training and information to employees and their representatives.

Definition of petroleum spirit

7 DSEAR (Schedule 6 Part 1) amend petroleum legislation to define petroleum spirit as:

petroleum which, when tested in accordance with Part A.9 of the Annex to the Directive, has a flash point (as defined in that part) of less than 21 ºC'.

8 The definition embraces petroleum products such as hexane, toluene and xylene, which are used as a solvent or raw material in the chemical and other manufacturing industries. In relation to PCA such chemicals are sometimes known as 'substances deemed to be petrol'.
Storage of petroleum spirit in cans and drums

9 Prior to 1990 the PLAs used the older Home Office Code of Principles of Construction and Licensing Conditions Part 1 Section 1: Storage of cans, drums and other receptacles. Since 1990 PLAs have been applying HSG51, The storage of flammable liquids in containers.

10 Prior to DSEAR HSE was already dealing with petroleum spirit in situations where petroleum spirit and other highly flammable liquids were kept in the same store. Inspectors should apply the standards in HSG51 to the storage of petroleum spirit (but see paras 11 and 12).

11 Installations meeting the standards of either of the above guidance documents are acceptable but there is a major difference between them. The older Home Office Code advocates a robust bunker approach with solid walls and a heavy concrete roof to provide protection to the store from external events. HSG51 advocates fire resistant walls (depending on location) but with a weak roof to act as explosion relief in the event of an incident within the store.

12 Because of the robust nature of the stores built to the Home Office Code there will still be many around and it is important to stress that there should be no need to seek difficult and costly upgrades to provide explosion relief in accordance with HSG51.

13 With DSEAR, PLAs no longer have the powers to licence the storage of petroleum spirit where it is not part of the refuelling of motor vehicles, etc. PLAs should provide any significant information on previously licensed stores to HSE/LA EHDs.
Tank storage

14 In addition to HSE taking on enforcement responsibility for petroleum can and drum stores in 2002, a number of tank storage facilities were also transferred to HSE, and in particular HID. These included the bulk storage of chemicals such as toluene, xylene, hexane and octane and any petrol storage depots with sub-COMAH quantities.

15 Such facilities were previously licensed under PCA. Many of these facilities have underground storage tanks (UST) because that was what PLAs normally asked for. Leak detection has always been a contentious issue with USTs and previous licence conditions for such tanks may have involved tank testing and stringent inventory control procedures.

16 Guidance for tanks is contained in HSG176 The storage of flammable liquids in tanks, which applies to both above and below ground fixed bulk storage tanks.
Workplace (non-retail) dispensing of petrol into motor vehicles, etc

17 DSEAR Schedule 6 Part 1 amends petroleum legislation to define a non-retail petroleum filling station as:

premises used, or intended for use, for dispensing petroleum spirit for use in motor vehicles, ships or aircraft, but it does not include any retail petroleum filling station'.

18 Schedule 6 part 1 of DSEAR also amends petroleum legislation to define the dispensing of petroleum spirit as:

'manual or electrical pumping of petroleum spirit from a storage tank into the fuel tank for an internal combustion engine, whether for the purposes of sale or not, and "dispenser" shall be construed accordingly'.

19 The non-retail refuelling with petrol of motor vehicles, etc may be encountered at a variety of premises. Such premises may include those occupied by police, fire and ambulance services or MoD. They may also include motor vehicle manufacture, e.g. car production lines, car hire depots, car sales showrooms and farms.

20 PLAs will continue to regulate such refuelling activities using PCA under the umbrella of the general legislative provisions in DSEAR. PLAs are responsible for the whole activity from the integrity of the storage tank to the act of an operator dispensing petrol into the motor vehicle, etc.

21. As HSE/LA EHDs will generally have enforcement responsibility under DSEAR for non petrol-related activities at non-retail petrol filling stations, there will need to be close liaison between enforcing authorities.
Dispensing of petrol other than into motor vehicles, ships and aircraft

22 PLAs only enforce PCA at retail and non-retail petrol filling stations. Any petrol dispensing activities at premises which fall outside these categories are regulated under DSEAR, with enforcement by HSE or the LA EHD as appropriate. The principal example is a petrol engine production plant where petrol is dispensed into engines on a test bed, but there is no fuelling of vehicles on the premises.

23 In situations such as the dispensing of petrol into jerry cans or into the fuel tank of a generator, these not being motor vehicles, enforcement falls to HSE/LA EHD under DSEAR. However, where the same dispensing equipment is also used for the refuelling of motor vehicles, etc PLAs will be responsible for the licensing of that equipment.
Liaison arrangements

24 The initial HSE contact for PLAs on petroleum enforcement issues is the local FOD enforcement liaison officer (ELO). The ELOs will decide whether the enquiry requires a legal or technical response. In the case of a routine legal query, e.g. procedural matters in respect of service of enforcement notices or the institution of legal proceedings, the ELO will deal with the matter in the usual way.

25. The Petroleum Enforcement Liaison Group (PELG) is a Local Authority Liaison Committee (HELA) working group set up to promote consistency amongst local authority PLAs in licensing and enforcement issues. It comprises representatives from local authority enforcers and HSE, and produces guidance on enforcement issues for PLAs who are encouraged to raise general issues within the group. Other guidance in the form of HELA Local Authority Circulars can be accessed on the HSE website under the heading petroleum[2]. Further information on PELG[3] can also be found on the website.

26 Technical enquiries from PLAs, e.g. in respect of the design or location of a petroleum installation, should be referred by the ELO to the appropriate process safety specialist. They will then deal with the query themselves, or they will refer it to the DSEAR Hub which will keep PELG informed of queries they receive, particularly if they have general application.
Guidance for inspectors

27 When inspecting can and drum storage or bulk storage of petroleum spirit, which is not part of a licensed activity, inspectors should apply the standards in HSGs 51 or 176 respectively. The standards are those that are currently applied for the storage of highly flammable liquids in general (but note para 12).

28 There is a set of technical ACOPs on DSEAR[4]. These ACOPs include additional advice on the safe storage of dangerous substances, e.g. on fulfilling the requirements for risk assessment.
Further information

29 Queries on the application of DSEAR to activities involving petroleum spirit may be directed to the Services, Transportation and Safety Unit or HID CI 4E as appropriate.
Cancellation of instructions

OC 293/5 version 3 - cancel and destroy
Appendix - Workplace regulation of petroleum spirit - some examples of activities and the corresponding enforcement arrangements
Activity Legislation Enforcing Authority Notes
At retail and non-retail petrol filling stations
Storage of petrol in tanks for fuelling of motor vehicles, etc DSEAR and PCA PLA -
Refuelling of motor vehicles, etc. with all fuels at retail petrol filling station DSEAR and PCA PLA -
Refuelling of motor vehicles, etc. with petrol only at non-retail petrol filling station DSEAR and PCA PLA Includes dispensing into vehicles on a production line
Dispensing of petrol into:
 mobile plant and machinery,
e.g. generators;
jerry cans PCA PLA -
Dispensing of petrol from airfield fuel bowser into small aircraft PCA PLA Where there are no fixed storage tanks on site and the bowser also acts as the fuel storage facility
Petrol recovery from scrap vehicles - with dispensing into other vehicles DSEAR and PCA PLA Site qualifies as a non-retail petrol filling station.
At premises other than retail and non-retail petrol filling stations
Dispensing of petrol, NOT as part of refuelling motor vehicles, etc DSEAR HSE/LA EHD Dispensing into:
fuel tanks for engines on a test bed;
Fuelling of small aircraft from petrol bowser DSEAR HSE Where bowser is used to transport fuel from fixed storage tank or hydrant to aircraft
Storage of petroleum spirit (PS) in cans and drums DSEAR HSE/LA EHD Highly flammable liquids store; petrol can store
Storage of PS in tanks (not related to fuelling motor vehicles, etc) DSEAR HSE/LA EHD Storage of toluene or xylene for use in a manufacturing process
Storage and dispensing of PS at COMAH/ NIHHS and MoD sites DSEAR COMAH: HSE with environment agencies; NIHHS: HSE and MoD: HSE -
Pouring, decanting or gravity feeding of PS DSEAR HSE/LA EHD Pouring petrol from a jerry can into the fuel tank for a motor vehicle, generator, cement mixer, etc.
Use of proprietary fuel retrievers in motor vehicle repair (OC 803/68 refers) DSEAR HSE/LA EHD Removal of petrol from vehicle fuel tanks and transfer to a suitable container
Petrol recovery from scrap vehicles - no dispensing into other vehicles DSEAR HSE/LA EHD -


Institute of Petroleum

ELECTRICAL INSTALLATION OF FACILITIES
FOR THE STORAGE AND DISPENSING OF
LPG AND CNG AUTOMOTIVE FUELS
AT VEHICLE REFUELLING STATIONS

November 2003

Published by
ENERGY INSTITUTE, LONDON
The Energy Institute is a professional membership body incorporated by Royal Charter 2003
Registered charity number 1097899

The Energy Institute gratefully acknowledges the financial contributions towards the scientific and technical program from the following companies:

Agip (UK) Ltd

Amerada Hess Ltd

BG Group

BHP Billiton Limited

BP Exploration Operating Co Ltd

BP Oil UK Ltd

ChecronTexaco Ltd

ConocoPhillips Limited

Conoco UK Ltd

Enterprise Oil plc

ExxonMobil International Ltd


Kerr-McGee North Sea (UK) Ltd

Kuwait Petroleum International Ltd

Murco Petroleum Ltd

Phillips Petroleum Co. UK Ltd

Shell UK Oil Products Limited

Shell U.K_ Exploration and Production Ltd

Statoil (U.K.) Limited

Talisman Energy (UK) Ltd

Total E&P UK plc

Total UK Limited

Copyright © 2003 by the Energy Institute, London

The Energy Institute is a professional membership body incorporated by Royal Charter 2001 Registered charity number 1097899, England

All rights reserved

No part of this book may be reproduced by any means, or transmitted or translated into is machine language without the written permission of the publisher.

The Energy Institute cannot accept any responsibility, of whatsoever kind, for damage or loss, arising or otherwise occurring as a result of the application of the information contained in this publication.

ISBN 0 85293 410 6

Published by the Energy Institute

Further copies can be obtained from Portland Customer Services, Commerce Way, Whitehall Industrial Estate, Colchester CO2 811P, UK. Tel: +44 (0) 1206 796 351 email This email address is being protected from spambots. You need JavaScript enabled to view it.

CONTENTS

Page

Foreword................................................................................................................................................................................. iv

Acknowledgements.............................................................................................................................................................

I Introduction......................................................................................................................................................................... 1

2 Consultation .......................................................................................................................................................................  2

3 Design standards ...............................................................................................................................................................  3

4 Area classification and separation distances .............................................................................................................  4

4.1 General ...................................................................................................................................................................  4

4.2 Dispenser zoning ................................................................................................................................................  4

4.3 Separation distances............................................................................................................................................. 4

5 Electrical supplies .............................................................................................................................................................  5

6 Selection, installation and location of equipment................................................................................................... 6

7 Isolation and switching .................................................................................................................................................  7

S Over current protection and discrimination .............................................................................................................  8

9 Protection against electric shock ..................................................................................................................................  9

10 Earthing and bonding............................................................................................................................................... 11

11 Wiring systems ..............................................................................................................................................................  12

12 Ducts and manholes .................................................................................................................................................  14

13 Force ventilated ducts and manholes ..................................................................................................................  15

14 Labels and warning notices ....................................................................................................................................  16

15 Inspection and testing ..............................................................................................................................................  18

Annex A

A.1 Hazardous area zoning.............................................................................................................................................. 20

A.2 Separation distances ................................................................................................................................................... 20

Annex B - References ......................................................................................................................................................  22

FOREWORD

The guidance included in this publication has been prepared by the Service Station Panel of the Energy Institute in consultation with a wide range of industry stakeholders, with the encouragement and support of the UK Health and Safety Executive (HSE).

The guidance is intended to assist those in the UK comply with the statutory Electricity at Work Regulations (1989) and petroleum storage legislation, with regard to electrical design and installation relating to the storage and dispensing of LPG and/or CNG as an automotive fuel.

The guidance includes key features of the electrical provisions of APEA/IP Guidance for the design, construction, modification and maintenance of petrol filling stations.

The guidance in this publication has primarily been prepared for use within the UK. However, those installing such facilities elsewhere may benefit from considering the guidance included herein.

The Energy Institute cannot accept responsibility, of whatsoever kind, for damage or loss, arising or otherwise occurring as a result of the application of the information contained in this publication.

Suggested revisions are invited and should be submitted to the Technical Department, the Energy Institute, 61 New Cavendish Street, London W 1G 7AR, UK.

ACKNOWLEDGEMENTS

This publication was prepared at the request of the Energy Institute's Service Station Panel by John Dallimore (John Dallimore & Partners) and Terry Hedgeland (Independent Consultant). It was subsequently reviewed by representatives of the following companies and organisations:

Association of Petroleum and Explosives Administration (APEA)

Association of UK qil Independents (AUKOI)

Berry & Co

BP

ChevronTexaco Ltd

ConocoPhillips

Electrical Contractors Association (ECA)

Esso Petroleum Company Ltd

J & R Gilbert

Health & Safety Executive

LP Gas Association (LPGA)

National Inspection Council for Electrical Installation Contracting (NICELC)

Petrol Retailers Association (PRA)

Petroleum Equipment Installers & Maintenance Federation (PEIMF)

Select

Shell UK Ltd

Tessa Stores Limited

Total UK

The Association for Petroleum and Explosives Administration (APEA) is thanked for agreeing to the reproduction of certain sections of text taken directly from APEA/IP Guidance for the design, construction, modification and maintenance of petrol filling stations.

1

INTRODUCTION

Liquefied Petroleum Gas (LPG) for use in motor vehicles, generally known as Autogas, is being encouraged in the UK as an alternative fuel because of its cleaner burning characteristics and environmental benefits. Autogas may be sold alongside other motor fuels at vehicle refuelling stations or at dedicated Autogas stations.

Compressed Natural Gas (CNG) similarly is available in the UK.

In the UK all vehicle refuelling stations storing and dispensing LPG or CNG are covered by the Dangerous


Substances and Explosive Atmospheres Regulations 2002 (DSEAR), whether dedicated to those fuels alone or in combination with petroleum. Other Health and Safety legislation applies in any event. Where LPG or CNG is installed at a vehicle refuelling station that is presently subject to petroleum licensing, the Petroleum Enforcement Authority (PEA) can attach conditions which relate to LPG or CNG, since the storage and dispensing of those fuels may impact with the storage and dispensing of petroleum.

2

CONSULTATION

The facilities needed at the LPGICNG/petroleum refuelling station should be ascertained as accurately as possible by consultation between the client and, as appropriate, the operator (if not the client), the architect, the consultant, the main contractor, the electrical contractor, the fitter storage and dispensing equipment manufacturer and installer, the cathodic protection contractor, the static protection contractor, the lightning protection contractor, the fire insurer, the electricity supplier, the enforcing authority and any other public authority concerned.

Documents should then be prepared and circulated for final written agreement, or comment, showing:


a)       details of the installation proposed, related extraneous-conductive-parts (e.g. tanks, pipework and structures) and additional electrical bonding;

b)       the accommodation and structural provisions required for the equipment (e.g. siting of switchgear and metering, central control point, emergency switching, etc.) and the provision of lighting and adequate access of all equipment;

c)       chases, ducts, manholes, draw-chambers, conduits, channels, trunking and other provisions required for electrical wiring.

3

DESIGN STANDARDS

This guidance on electrical installations incorporates and, where appropriate, supersedes earlier recommendations contained in publications from IP, APEA, LPGA and other sources.

The design and installation should, in general, comply with the electrical provisions of APEA/IP Guidance for the design, construction, modification and maintenance of petrol filling stations. Key features of that publication and additional or alternative provisions


for LPG and CNG installations are identified further in this publication, which should be used in conjunction with Guidance for the design, construction, modification and maintenance of petrol filling stations.

For guidance on non-electrical aspects relating to Auto gas, reference may be made to the LPGA suite of Codes of Practice which cover most aspects of storage and transportation.

4

AREA CLASSIFICATION AND

SEPARATION DISTANCES

4.1 GENERAL

Hazardous area zoning for LPG/CNG installations is based on the fundamental criteria given in BS EN 60079-10:2003 for Zones 0, 1 or 2 as applied to petroleum and other potentially explosive products.

Electrical equipment installed in a zoned area must be appropriately explosion-protected for installation in that area.

By implication, an area which is not classified as Zone 0, 1 or 2 is deemed to be non-hazardous with respect to the selection of electrical apparatus.

Descriptions of hazardous area zones are given in Annex A. Details of hazardous area zoning around LPG storage vessels, pumps and delivery vehicle connections are given in IP Model Code of Safe Practice Part 15 Area classification code for installations handling flammable fluids. LPGA Code of Practice Part 1, gives separation distances between LPG vessels and buildings and other items of equipment.

Where provisions for storage and dispensing LPG or CNG are to be added to a site dispensing petroleum, and the zoning for these fuels may overlap with zoning of petroleum-related equipment, care must be taken to satisfy the more extensive zoning requirements for the LPG or CNG.

4.2 DISPENSER ZONING

For consistency with other fuel dispensers (e.g. complying with BS 7117) LPG/CNG dispensers should


be considered as petrol dispensers with stage 2 vapour recovery but without the vent air separator. General zoning requirements for petrol dispensers are given in Guidance for the design, construction, modification and maintenance of petrol filling stations.

As with petrol dispensers the zoning within and immediately above the housing of an LPG/CNG dispenser will depend on the internal construction (e.g. employing vapour barriers). Knowledge of the dispenser internal zoning is essential.

A manufacturer/importer or someone marketing a dispenser should supply with the unit a diagram showing the zoned areas in and around the unit. This should be available at the design stage.

An alternative is to apply the area classification for Autogas dispensers shown in LPGA Code of Practice 20.

4.3 SEPARATION DISTANCES

In order to ensure clearance from an item of LPG equipment to other items of equipment, buildings or potential sources of ignition, guidance on separation distances has been established.

Tables 1 and 2 in Annex A provide guidance on separation distances between a range of components and other objects.

5

ELECTRICAL SUPPLIES

Electrical supplies for the LPG/CNG installation should comply with the relevant provisions of Section 14.3 of Guidance for the design, construction, modification and maintenance of petrol filling stations.

Essential features to be considered include the following.

— A plan of the LPG/CNG installation should be appended to the existing site plan displayed within the premises.

The LPG/CNG installation should not be installed below overhead conductors (electricity, telephone lines, etc.), except where protected overhead by an earthed metallic canopy as detailed in Guidance for the design, construction, modification and maintenance of petrol filling stations,

At an existing vehicle refuelling station, an


assessment should be made of the incoming electricity supply and main switchgear with regard to its ability to accommodate the proposed LPG/CNG installation.

On a stand-alone LPG/CNG site, the specific recommendations of Section 14.3 of Guidance for the design, construction, modification and maintenance of petrol filling stations apply in full.

A risk assessment should be carried out by the designer to determine the need for lightning protection of structures at the LPG/CNG location.

Where protective multiple earthing (Plv1E) exists as the means of earthing the site, particular attention should be given to the possible effect of diverted neutral currents passing into hazardous zones via metalwork and protective conductors.

6

SELECTION, INSTALLATION AND

LOCATION OF EQUIPMENT

The following features relating to the selection, installation and location of equipment include a summary of the provisions of Sections 14.4 and 14.5 of Guidance for the design, construction, modification and maintenance of petrol filling stations, which should be applied to installations for dispensing LPG or CNG to road vehicles.

Equipment should be certified to an explosion protection standard suitable for the zone in which it is to be used – only equipment constructed to comply with The Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 1996, or an appropriate British, harmonized European, equivalent international standard and with ATEX should be used.

Associated equipment installed in a non-hazardous area must not have an adverse effect on the explosion-protection concept of the equipment located in the hazardous area.

— Equipment, which when operating displaces or ingests air, (e.g. vacuum cleaning equipment with extended hose, car wash, warm air central heating or air compressors) should not be installed where it may affect, or be affected by, a potentially explosive atmosphere.

— In addition to an electrical enclosure being suitably


explosion-protected, protection against adverse environmental conditions, particularly the ingress of moisture or water, must be provided by an enclosure having an appropriate 'Index of Protection' (IP number).

— Where a tank and pipework system incorporate plastics components with isolated metal parts, protection against static electricity may be required. Detailed provisions for this form of protection are given in 14.4.6 of Guidance for the design, construction, modification and maintenance of petrol filling stations.

Where cathodic protection of LPG/CNG tanks and pipework is required, comprehensive guidance on the subject is given in IP Guidance on cathodic protection of underground steel storage tanks and steel pipework at petrol filling stations.

Any LPG/CNG dispenser should be covered by the site loudspeaker warning system. The loudspeaker warning system should be separate from the dispensers and not controlled by the emergency switching system.

Lighting of the LPG/CNG compound and associated road tanker delivery area should be designed to ensure an illuminance of 100 lux at ground level in these areas, allowing for a delivery vehicle to be in position.

7

ISOLATION AND SWITCHING

The following features relating to isolation and switching include a summary of the provisions of Section 14.6 of Guidance for the design, construction, modification and maintenance of petrol filling stations.

—    Means of isolation and switching must comply with Regulation 12 of the Electricity at Work Regulations 1989 (as amended).

—    For stand-alone LPG/CNG installations, the provisions of Section 14.6 of Guidance for the design, construction, modification and maintenance of petrol filling stations apply in general.

Devices for the isolation and control of LPG electrical equipment should interrupt simultaneously all live poles, including the neutral. Other than isolating devices adjacent to pumps, which must be suitably explosion- and ingress-protected, devices for isolation and control should be located in a non-hazardous area.


—    Devices for isolation for electrical maintenance purposes must have locking-off facilities. Fuse carriers are not acceptable.

—    An emergency switching device should be provided at each entrance/exit of the LPG/CNG compound.

Where a tank and fill point are installed underground, an emergency switching device must be provided in a non-hazardous area adjacent to the tanker stand. This device may be within a driver controlled delivery (DCD) facility.

The electrical circuits, other than any incorporating certified intrinsically safe equipment, to the LPG/CNG pump(s) and dispenser(s) should be arranged such that. on the operation of an emergency switch on the refuelling station, the LPG/CNG pump(s) and dispenser(s) and also the petrol pumps and dispensers are ALL electrically de-energised – the supply should be capable of being reset only from inside the console area.

OVERCURRENT PROTECTION

AND DISCRIMINATION

The following features of overcurrent protection and discrimination include a summary of the provisions of Section 14.7 of Guidance for the design, construction, modification and maintenance of petrol filling stations, which should be applied to installations for dispensing LPG or CNG to road vehicles.

— Discrimination of operation of series devices must be ensured for both fault current and overload protection.

— For residual current devices in series the supply side device should be time-delayed to ensure discrimination of operation.

Every fault current device and residual current device should have fault breaking capacity not less than the prospective fault level at its point of installation.


— If separate devices are employed for fault current and overload protection, their characteristics should be co-ordinated and each device labelled to show its function.

Each dispenser circuit (including integral lighting and ancillary circuits other than data and signalling circuits not liable to overload or fault currents) should be individually protected against overload and fault currents by a suitably rated multi-pole circuit breaker arranged to break all live conductors including the neutral.

— If the circuit breaker is suitable for, and is provided as, a means of isolation it must have locking-off facilities.

9

PROTECTION AGAINST ELECTRIC

SHOCK

The following features of protection against electric shock include a summary of the provisions of Section 14.8 of Guidance for the design, construction,

modification and maintenance of petrol filling stations, which should be applied to installations for dispensing LPG or CNG to road vehicles.

Protection against indirect contact should be provided by earthed equipotential bonding and automatic disconnection of supply or by use of equipment of Class II construction (double insulated) where it is under effective supervision in normal use.

— Where bonding is required, it must be provided locally across the gap between the items to be bonded, regardless of bonding elsewhere.

— The automatic disconnection of supply to forecourt circuits must not exceed 100 ins in the event of an earth fault.

Where a single device provides protection against overload, fault current and indirect contact it must break phase and neutral conductors, i.e. a multi-pole circuit breaker (CB) or residual current circuit breaker with overcurrent protection (RCBO) is required - fuses must not be used.

— Extra-low voltage data and other systems not intrinsically safe should be provided by the installation of SELV circuits (separated extra-low voltage) supplied via a BS 3535 (BS EN 60742)


safety isolating transformer or equivalent safety source - neither the live parts nor the exposed metalwork of the SELV circuit should be earthed.

Where a vehicle refuelling station installation is part of a TT system, or where earthing arrangements are such that disconnection times cannot be achieved with overcurrent protective devices, residual current devices (RCDs) will be required to facilitate automatic disconnection of supply.

— It is inappropriate to provide a single 'front end' RCD at the main switch position as the sole means of earth fault disconnection for the installation.

Circuits will usually be RCD protected individually in order to satisfy site operational requirements - in any event an RCD incorporated in a circuit serving a hazardous area should be independent of RCDs protecting non-hazardous area circuits.

— If RCDs are connected in series, discrimination of operation of a load side device must be ensured by incorporating a supply side device having a suitable time-delay.

— For each RCD the leakage current of the associated circuit must not exceed 25 % of the rated residual current of the RCD.

— Where mineral insulated cable having circuit conductors of 2,5 min2 or less cross-sectional area

ELECTRICAL INSTALLATION OF FACILITIES FOR THE STORAGE AND DISPENSING OF LPG AND CNG AUTOMOTIVE FUELS AT VEHICLE REFUELLING STATIONS

(csa), installed to meet specified conditions, is protected by a circuit breaker complying with BS 3871 or BS EN 60898 and having a rating of 32A Of less, the automatic disconnection requirements for indirect contact shock protection are deemed to be met.

10

EARTHING AND BONDING

The general guidance on earthing and bonding in Section 14.8 of Guidance for the design, construction, modification and maintenance of petrol filling stations should be applied to LPG/CNG installations.

Particular attention should be given to the following.

Where the site earthing system is connected to a PME terminal, a risk assessment should be carried out to determine any possible adverse effects on the LPG/CNG installation — where the metalwork of the LPG/CNG installation is cathodically protected and employs isolating joints, the effects of diverted neutral currents should be obviated.

An earthing bar or terminal should be provided in every enclosure of electrical equipment, other than equipment specified as having Class 2 construction.

Care should be taken to ensure that the earthing arrangements for data cable screening do not introduce potentially dangerous levels of ignition energy into a hazardous area - generally screening should be earthed at one point only.

Provision should be made for the electrical connection of LPG/CNG road tankers to the metalwork of the LPG/CNG system. The terminal or other provision, which must not be located in a


manhole or other hazardous area location, should be suitable for making a bond to the tanker prior to the commencement of, and until completion of, the final transfer operation. Where the LPG/CNG tank and pipe metalwork are cathodically protected, care should be taken to ensure that provision of the tanker bonding point_ when in use, does not bridge the cathodic protection arrangements.

Where an LPG or CNG electrical installation does not share a site with facilities for dispensing of petroleum or other fuels, an all-insulated test socket for measuring earth loop impedance and prospective fault current should be installed at the origin of the installation in conjunction with the main earth terminal test link - a suitably labelled insulated protective conductor which is segregated from the earthing arrangements within the installation should connect the earth terminal of the test socket to the earthing conductor side of the main earth terminal test link.

The test socket and its related all-insulated device incorporating isolation and overcurrent protection should comply with 14.4.4 of Guidance for• the design, construction, modification and maintenance of petrol filling stations. The means of isolation should be capable of being locked and should be provided with a label identifying its purpose (see Section 14 for label details).

11

WIRING SYSTEMS

The following features of wiring systems include a summary of the provisions of Section 14.9 of Guidance for the design, construction, modification and maintenance of petrol filling stations, which should be applied to installations for dispensing LPG or CNG to road vehicles.

— All conductors (other than prescribed bonding bridges) having a CSA of 16 mm2 or less should be copper.

Every protective conductor not forming part of a cable or cable enclosure should be identified throughout by green/yellow insulating covering.

Contact between cables of intrinsically safe (IS) circuits and those which are non-intrinsically safe should be prevented - preferably running the IS cables in a non-conducting duct or pipe reserved solely for that purpose.

IS conductors must not be run in the same multicore cable with non-IS circuit conductors - nor in the same enclosure or duct with non-IS circuits unless segregated by an earthed metal screen or shield.

— Particular attention should be given to the construction of cables for IS circuits so as to ensure that they are not damaged by the installation of other cables sharing a common duct.

— Care should be taken to ensure that metallic


screening or sheaths of IS circuit cables are earthed at one point only and do not constitute an earth path for electrical fault current or currents which could adversely affect transmitted data.

Where extra-low voltage circuits (ELV = not more than 50 Va.c., 120 Vd.c.) are contained in the same trunking. duct or multicore cable as higher voltage circuits, the latter must be provided with an earthed metallic screen or sheath with a current carrying capacity equivalent to that of the higher voltage cores. Alternatively, the conductors of an ELV system should be insulated individually or collectively for the highest voltage present on other conductors in the same enclosure. The higher voltage grade insulation should be applied throughout the ELV system.

All cables installed underground or in site-formed ducts should be laid at a depth of not less than 500 mm or be otherwise protected against mechanical damage.

Cables laid directly in the ground should be protected by cable covers or identified by suitable marking tape.

— Cables laid or drawn into ducts should be of such construction that that they are not liable to be damaged by the drawing in or withdrawal of other cables.

In any location available for vehicular access,

ELECTRICAL INSTALLATION OF FACILITIES FOR THE STORAGE AND DISPENSING
OF LPG AND CNG AUTOMOTIVE FUELS AT VEHICLE REFUELLING STATIONS

cables, bunking or other electrical enclosures should be positioned or additionally protected to a height of 1,5 m so that they are unlikely to be damaged by moving vehicles.

The protective conductor for every circuit supplying low voltage equipment (eg, 230 V power) in a hazardous area should be provided by means of an integral cable core in addition to any protective function provided by a cable sheath or annum.

— Types of cable are specified, mineral insulated cable terminated with earth tail pots and glands approved for Zone 1 or Zone 2, as appropriate, being preferred.

Steel wire armoured cables terminated with glands approved for Zone 1 or Zone 2, as appropriate, in hazardous areas may be employed subject to the installation of earth tag washers at the cable glands in non-hazardous areas - a lugged cable connection (cable same csa as related phase conductor, minimum 2,5 mm2) being provided between the


earth tag washer and enclosure earthing bar or terminal.

Alternatively, steel wire braided cable having hydrocarbon resistant outer covering may be employed if it is terminated in shrouded glands which provide mechanically and electrically sound anchorage for the steel wire braid and which are suited to the zoning of the hazardous area to maintain the integrity of the explosion protection concept.

Other cable is acceptable only if it forms part of an intrinsically safe (IS) circuit and, if multicore, contains only IS circuits and is not run with other circuits in a common duct unless the other circuits are separated from, the IS circuit(s) by a suitable earthed metallic screen or barrier.

— Within Zone 0 hazardous areas the previously described cables are acceptable providing they form part of a system certified as intrinsically safe for Zone 0, or pass unbroken through the Zone.

12

DUCTS AND MANHOLES

The following are general features applicable to ducts and manholes of LPG/CNG installations.

Duct systems for underground cables in hazardous areas must be designed and constructed to minimise the possibility of fuel or vapour entering other areas or accumulating within the duct system.

— Electric cables should not be enclosed in the same duct as LPG/CNG pipelines.

Ducts must be impervious to water and fuel products.

Manholes, cable chambers and draw boxes should be water and fuel tight, constructed of GRP, polythene or engineering brick.

Comprehensive guidance on the provision of underground cable duct systems is given in


Guidance for the design, construction, modification and maintenance of petrol filling stations.

Other than for duct systems which are suction fan vented, it is of the utmost importance that, before any fuel is brought on site, duct terminations are adequately sealed in underground chambers, at dispensing equipment, the central control point and particularly where ducts pass from hazardous to non-hazardous areas.

— Sealing should be achieved with suitable compound or other material resistant to hydrocarbon products and their vapours, all spare and unused ducts first being fitted with tapered hardwood plugs - cable pits, trenches and manholes should not be sand filled and or screeded.

13

FORCE VENTILATED DUCTS

AND MANHOLES

Where a force ventilated system is employed to avoid a build-up of vapour in ducts and manholes associated with the LPG/CNG system_ the following points should be noted.

Guidance for the design, construction, modification and maintenance of petrol filling stations does not contain guidance on this subject.

— The ventilation unit should not be controlled by the emergency switching arrangements for the pump systems.

— The ventilation unit must be certified for use in Zone 1.


— Ventilated ducts and manholes should be totally segregated from all other ducts and manholes.

The ventilated ducts must not be sealed or obstructed in any way.

— Where the ventilation system incorporates a vent pipe. the pipe should be treated as a petroleum vent pipe without vapour recovery for the purposes of zoning.

— Electrical equipment, including cable, must not be mounted on the vent pipe.

14

LABELS AND WARNING NOTICES

The following features of wiring systems include a summary of the provisions of Section 14.9.8 of Guidance for the design, construction, modification and maintenance of petrol filling stations, which should be applied to installations for dispensing LPG or CNG to road vehicles.

Labels should be of a permanent nature, e.g. 'sandwich' plastics material resistant to adverse effects of weather and hydrocarbons, so that paint filling of engraved characters is not required - use should be made of contrasting colours, e.g. black against white background, white against red background, etc. as appropriate.

— Labels and their lettering should be sized in proportion to equipment on which they are to be mounted and should be securely fixed.

Where equipment must not be drilled, e.g. explosion-protected or watertight apparatus, a suitable adhesive should be used. the maker's recommendations on preparation of surfaces, etc. being fully observed.

— Where adjacent equipment has interchangeable removable covers, labels should not be fitted to covers but should be in fixed positions.

If any labels are provided to warn of a significant risk to health and safety, or are required under any other relevant law, they must comply with the Health and Safety (Safety Signs and Signals) Regulations 1996.


A conspicuous, durable and legible notice must be fitted adjacent to the main isolating switch for the refuelling station electrical installation and at any equipment at which cathodically protected metalwork is simultaneously accessible with other earthing arrangements, bearing the words: "ALL OR PART OF THE TANKS AND PIPEWORK AT THIS SITE HAS CATHODIC PROTECTION".

The isolating device for the test socket at the origin of the installation should be labelled "THIS DEVICE IS NOT ISOLATED BY THE MAIN ISOLATING SWITCH AND MUST REMAIN LOCKED IN THE OFF POSITION WHEN NOT BEING USED FOR TEST PURPOSES".

On all luminaires within a hazardous area, the maximum permissible lamp wattage should be clearly indicated by a permanent label securely fixed and readily visible when re-lamping the luminaire - on small illuminated components, the lamp voltage and wattage should be indicated.

Where electrical equipment cannot be isolated by a single device, unless suitable interlocking is provided, a suitable warning notice, clearly identifying all the isolation devices, should be permanently fixed in a prominent position, visible before access to live parts can be gained.

A conspicuous, durable and legible notice must be fitted adjacent to the operating means of each emergency switching device (the operating means

ELECTRICAL INSTALLATION OF FACILITIES FOR THE STORAGE AND DISPENSING OF LPG AND CNG AUTOMOTIVE FUELS AT VEHICLE REFUELLING STATIONS

being coloured red against a yellow background) within the LPG/CNG storage compound, bearing the words "EMERGENCY. LPG PUMP - SWITCH OFF HERE" (or CNG where relevant).

Each other emergency switch accessible to staff and the general public must have fitted adjacent to it a conspicuous_ durable and legible notice bearing the words "LPG (or CNG where relevant) AND PETROL PUMPS SWITCH OFF HERE".

Where high voltage lighting or signs are associated with an LPG or CNG installation the associated external electrical switch provided for emergency use should have displayed adjacent to it the notice '1-1IGH VOLTAGE SIGN. FIREMAN'S SWITCH'.


Where electrical apparatus within a dispenser cannot withstand a 500 Vd.c. insulation test, the means of safe disconnection for test purposes must be identified and clearly labelled.

- Labels warning where to isolate equipment electrically before removing electrical enclosure covers must be mounted within a dispenser housing and be clearly visible when the inside of the dispenser housing is exposed.

- A conspicuous, durable and legible notice must be fitted adjacent to the terminal or other provision for earth bonding of road tankers during fuel transfer_ bearing the words: "TANKER EARTH BONDING POINT".

15

INSPECTION AND TESTING

The inspection and testing of electrical installations associated with the dispensing of LPG or CNG to road vehicles should, in general comply with the comprehensive guidance given in Guidance for the design, construction, modification and maintenance of petrol filling stations.

Dispensers for LPG and CNG, including refurbished units, should be certified by an accredited testing and certifying body as complying with BS 7117 Part 1, an equivalent harmonised European or international standard and with ATEX.

With regard to the installation status and selection of verification program it will be necessary to ascertain that the LPG or CNG dispensers are appropriately certified as explosion-protected and incorporate the features of B S 7117 (for metering pump and dispensers) which are relevant to safe inspection and testing of the associated electrical installation.

BS 7117 relates only to metering pump/dispensers; it does not contain requirements for other aspects of refuelling station installations.

Electrical requirements in BS 7117 include:

— Zoning for electrical apparatus within a dispenser, dependent on the presence of prescribed vapour barriers.

All electrical apparatus within a dispenser must be able to withstand a 500Vd.c. insulation test or have a means of safe disconnection without dismantling. Such facilities must be identified and clearly labelled.


Extra-low-voltage circuits in hazardous areas (ELV = not more than 50Va.c., 120V ripple-free d.c,) must be terminated in an explosion-protected terminal box separate from that for the supply cables.

All internal metal enclosures of electrical apparatus must be connected to a main earth connecting facility in or on the metering pump or dispenser.

A bonding terminal (for testing) must be provided within the housing.

All cables and cable terminations must be labelled and easily identified from manufacturers' drawings.

— Labels warning to isolate equipment electrically before removing electrical enclosure covers must be mounted within a dispenser housing and be clearly visible when the inside of the housing is exposed.

— Instructions must be provided for the safe installation and operation of the dispensing equipment, for retention with site records.

Items additional to those detailed in Guidance for the design, construction, modification and maintenance of petrol filling stations to be inspected and or tested include the following:

— The condition and continuity of the earth bonding

ELECTRICAL INSTALLATION OF FACILITIES FOR THE STORAGE AND DISPENSING
OF LPG AND CNG AUTOMOTIVE FUELS AT VEHICLE REFUELLING STATIONS

terminal or other provision for bonding a tanker during fuel transfer.

— The condition and continuity of metal bridges bonding across flanges or other couplings in accessible fuel lines.

The condition and adequacy of insulation  materials around and adjacent to isolating joints separating cathodic a Hy protected parts from other metal work.


Final inspection of the electrical installation should include checking that cathodic protection isolating joints in pipework have not been by-passed by protective conductors or other means such as tanker earthing facilities.

Particular attention is drawn to checking that the integrity of 'Ex' terminations and enclosures within dispensers is maintained.

ANNEX A

A.1 HAZARDOUS AREA ZONING

Any equipment containing a flammable liquid or vapour requires to be assessed to determine the potential for forming a flammable atmosphere. This is usually called zoning and the zones are divided into:

Zone 0 An area in which flammable gas-air mixture is continuously present or is present for long periods.

Zone 1 An area in which a flammable gas-air mixture is likely to occur in normal operations.


the areas to be determined. A variety of published information may be used to assist competent persons with this work.

Electrical equipment installed in a zoned area must be of suitable design for installation in that area and must be correctly installed and maintained by competent persons.

LP Model Code of Practice, Part 15 Area classification code for installations handling flammable fluids gives details of hazardous area zoning around LPG tanks, vent pipes. dispensers, etc.

A.2 SEPARATION DISTANCES

Zone 2 An area in which a flammable gas-mixture is not likely to occur in normal operations and if it occurs it will only exist for a short time.

By implication an area which is not classified Zone 0, 1 or 2 is deemed to be non-hazardous with respect to the selection of electrical apparatus.

The final responsibility for establishing zoned areas is with the end user. It is the responsibility of the designer/installer to provide the information to allow


Separation distances are established to ensure clearance from a vessel and/or associated equipment, buildings or potential sources of ignition which, if these caught fire, would pose a risk to the vessel or the associated equipment.

LPGA Code of Practice Part 1, gives separation distances between LPG vessels and buildings and other items of equipment.

Table I - Distances from buildings, boundaries and fixed sources of ignition

 

Minimum separation distance

LPG tank size
(tonnes)

Buildings, boundary or
fixed ignition source
(metres)

With fire wall*
(metres)

0,25 to 1,1

3

15

1,1 to 4

75

4

4 to 10

15,0 a/g
7,5 u/g

7,5 a/g
4,0 uig

* Dispersion wall for underground vessels

Notes:

i)         Separation distances are to valve assemblies and flanges for underground or mounded vessel systems and to the vessel surface for above ground systems. For below ground or mounded vessels a separation distance to the vessel surface of 1,0 m for tanks up to 1,1 tonnes and 3,0 in for vessels over this size should be maintained.

ii)       Separation distances should not be confused with hazardous area zoning (see following).

iii)      Separation distances may be revised subject to the presentation of appropriate acceptable risk modelling data to the Competent Authority.

ELECTRICAL INSTALLATION OF FACILITIES FOR THE STORAGE AND DISPENSING
OF LPG AND CNG AUTOMOTIVE FUELS AT VEHICLE REFUELLING STATIONS

Table 2 - Minimum separation distances
(Distances are as seen in plan view)

   

Storage
vessel

Storage vessel
fill connection

LPG pump

LPG
dispenser

Vehicle
being
filled

  1. 1.      

LPG storage vessel

See CoP 1
Part 1

Nil

Nil

but not beneath
vessel

0,5 in

3 in

  1.  

Storage vessel filling connection

Nil

 

Nil

1,0 m

3 in

  1.  

LPG pump

Nil
but not
beneath
vessel

Nil

 

Nil

1,5 in

  1.  

LPG dispenser

0,5 in

1 in

Nil

 

Nil

5

Vehicle being filled

3 m

3 m

1,5 ni

Nil

 
  1.  

U/G petrol vessel manhole with fill connection

7,5 m

7,5 m

7,5 in

7.5 in

Nil

  1.  

U/G petrol vessel manhole without fill connection

3 in

3 m

3 m

3 m

Nil

  1.  

Above ground vessel for liquids

< 65 °C flash point

As CoP Part 1 Table of safety distances
for flammable liquids

  1.  

Remote petrol vessel fill connections

7,5 m

7,5 in

7,5 na

7,5 m

Nil

 

Petrol vessel vents

7,5 in

7,5 in

7,5 In

7,5 m

Nil

  1. 11.   

Petrol dispensers - explosion-protected diesel dispensers - explosion-protected

7,5 in

3 m

7,5 m

3 m

7,5 m

Nil

Nil

Nil

Nil

Nil

 

Parked cars

6 m or separation distance in Table 1 if

less

6m
or separation
distance in Table
1 if less

1,5 m

Nil

Nil

 

Buildings, boundary or fixed source of ignition

As Table 1

4,0 in

4,0 ni
from
vehicle fill
point

ANNEX B

REFERENCES

British Standards Institution (BSI)'

BS 3871 Part 1 Specification for miniature and moulded case circuit-breakers. Miniature air-break circuit-breakers for a. c. circuits.

BS 7117 Part 1 Metering pumps and dispensers to be installed at filling stations and used to dispense liquid fuel - Specification for construction.

European Committee for Standardization (CEN)'

EN 60079-10 Electrical apparatus for explosive gas atmospheres - Classification of hazardous areas.

EN 60742 Isolating transformers and safety isolating transformers - Requirements.

EN 60898 Specification for circuit-breakers for overcurrent protection for household and similar installations.


EP publications from the Energy Institute3

Guidance on external cathodic protection of underground steel storage tanks and steel pipes cork at petrol filling stations.

Model Code of Safe Practice in the Petroleum Industry Part 15 Area classification code for installations handling flammable fluids.

Liquefied Petroleum Gas Association'

Code of Practice Part 1 Design, installation and operation of vessels located above ground.

Code of Practice Part 20 Automotive LPG refuelling facilities.

Available from British Standards Institution, 389 Chiswick High Road, Chiswick, London, W4 4AL, UK. Tel: +44 (0)20 8996 9001, www.bsi-global.coin

Available from national standards organizations, e.g. BSI

'Available from Portland Customer Services, Commerce Way, Whitehall Industrial Estate, Colchester, CO2 SHP. Tel: +44 (0)1206 796 351,

4 Available from the LP Gas Association, Pavilion 16. Headlands Business Park, Salisbury Road, Ringwood, Hampshire BH24 3PB, UK.

In case you miss any information or just want to give us feedback, please feel free to contact us.

Petroleum storage testing.

Frequently Asked Questions

My testing options?

electrical safety testing in action

Please see the Electrical Testing menu above for a complete description of Electrical Testing & safety in the place of work and in your home .In particular how and why we test the way we do. We are situated on the Kent, Sussex and Surrey borders.This electrical testing site has been designed and built by GadSolutions and is hosted on one of their servers.

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The consequences of electrical testing.

You should be aware that to do the electrical testing the entire installation needs to be de-energised for 5 minutes (do you have a server?). Each circuit while it is being tested needs to be de-energised while the test takes place. Except for production lines normal businesses can carry on with minimal disruption

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Out of hours testing.

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Electrical safety testing ,Southern testing.