Meter Field Testing and Installation Practices
Here, we discuss the installation, commissioning and field testing of meters.
Energy Meters - Installation and Commissioning
The meters are linked before the consumer's isolating device (Main Switch) that might be a moulded case miniature circuit breaker, circuit breaker, or an ironclad switch fuse unit. At the time of commissioning, every meter is tested at site through the owner. A reference standard meter of 0.2 classes or better is used for testing.
Supply Side Wiring
The supply side wiring is the responsibility of the utility and the subsequent must be ensured although carrying it out:
a) The supply wires given are of suitable rating.
b) In case of more than one meter on one service line, it is preferable to use bus-bars. While a number of meters are linked to single distributing mains for registering electricity supplied to various consumer loads, separate service lines - phase(s) and neutral, are used for every meter. Each independently metered consumer load is directly linked to distributing mains by its meter connected in specified phase sequence so as to meet accuracy requirements of relevant standard.
c) The supply wire is properly terminated.
d) The connection is as per links diagram mentioned on meter.
e) Utility should use its own earthing for its devices.
Utility gives phase and neutral supply to the consumers. The neutral is used for carrying return current only. The neutral of one consumer should not be linked to other consumers who have independent and separate supply connection. Utility provides separate neutral to every consumer up the metering point and similar is used through the consumer. The consumer ensures in which all the correct wiring practices are followed and neutral is not looped along with another consumer or meters in the similar premises. Consumer should not earth the neutral after the metering point. While there are multiple meter installations, bus bar arrangement is used for neutral, so that looping is prevented.