Page 47 - Gi flipbook May 2018

IGEM NEWS | Technical Standards

NEW GAS METERING

EQUIPMENT STANDARDS

WHAT YOU NEED TO KNOW

Two IGEM standards have been reviewed under the currents for reed’s wetting currents.
chairmanship of Larry Wallis and are now available from Panel discussed the difficulties (or
the IGEM shop. Here, Larry tells you everything you need to otherwise) of the Ui value of 10V for
Ex ib and Ex ia certification
know about IGEM/GM/7A Edition 2 Electrical connections • Review of other pulse specifications/
for gas metering equipment and IGEM/GM/7B Edition 2 electrical issues known to the panel
Hazardous area classification for gas metering equipment that may be causing difficulties
• Agreement and clarification of
installation of equipment in
THESE TWO STANDARDS were science available to the industry. The hazardous area deemed to be NE
published in 2008 and, since then, changes in the use and application of • Updates and corrections of minor
both the industry and the research electronic devices to monitor metering errors in drawings
has moved on. In 2010, the installations has moved on at a pace, • Updated contractual requirements
publication of IGEM/SR/25 Edition 2 which meant there was also a need to • Review of industry comments
followed research undertaken by the update IGEM/GM/7A. relating to operator difficulties with
Health and Safety Laboratories, installation (e.g., installation of AMR
introducing the concept of hazardous The scope of work in IGEM/GM/7A and pulse splitters, etc.)
area zones of negligible extent (NE) included, but was not restricted to:
and less conservative zoning distances • Changes to electrical specifications COMMERCIAL ARRANGEMENTS
in many cases. This meant IGEM/ e.g., 10Hz burst, increased values and Before connecting any electrical
GM/7B was out of step with the latest pulsing (hi start, low continuous) equipment (including optical
equipment) to a meter installation,
the meter asset manager (MAM) and
the owner of any electronic
FIGURE 1: Example of the position of an installation, split between HP and LP equipment, equipment attached to the
within a building/enclosure and its related hazardous area
installation, such as an energy
management system (EMS), needs to
be contacted to give their permission.
The connection or disconnection of
any equipment is not to adversely
affect the safety or accuracy of the
meter reading or the readings of
subsidiary equipment.
Priority for connections to
equipment must be given to those
directly incorporated in the
measurement chain used for billing,
which is to be installed in a manner
that minimises its dependency on
other items of equipment.
The organisation operating the
equipment (including volume
conversion devices, AMR and the
meter) should be connected together
and is responsible for the safe and
efficient operation of that equipment.
There are two types of metered sites:
1. Non-daily metered (NDM) sites
The gas supplier has a regulatory
requirement under the Gas Supply
Standard Licence Conditions to
ensure that gas supplied to a
designated premise is supplied

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