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METER TYPE FORMS FOR VARIOUS TRANSFORMER CONFIGURATIONS


METER TYPE FORMS FOR VARIOUS TRANSFORMER CONFIGURATIONS
What are the meters used for single phase and three-phase transformer configuration?

In any distribution utility, the type of loads varies significantly. Some loads are supplied through single phase transformers, some through three phase transformers, some also utilizes line to ground configuration while others line to line configurations. Correspondingly, the above mentioned configurations also require specific type of metering which should be compatible to the type of connections used.

Found below are some of the common transformer configurations that an electric utility use in its distribution system. Different type of configuration requires each own type of metering standards.

Transformer configuration

Two-wire (2W) single phase transformer
• A single phase transformer with line to ground service configuration.
Three-wire (3W) single phase transformer
• A single phase transformer which service configuration has center tap neutral ground connection.
Three-wire wye (3WY) three phase transformer
• A three phase transformer or a three 1-phase transformers which service configuration is banked as ungrounded wye.
Three-wire delta (3WD) three phase transformer
• A three phase transformer or a three 1-phase transformers which service configuration are banked as delta with one phase grounded
Four-wire delta (4WD) three phase transformer
• A three phase transformer or a three 1-phase transformers which service configuration are banked as delta with center tap ground connection.
Four-wire wye (4WY) three phase transformer
• A three phase transformer or three 1-phase transformers which service configuration are banked as wye with neutral ground connection.

Various KWH Meter Configurations

As mentioned a while ago, single phase and three phase transformers requires each its own type of kWh meter configuration. The following are some of the known forms of kwh meter configurations used by utility known as “forms”.

Form 1 - A single phase kWh meter, two-wire, single stator, self-contained meter.
Form 2 - A single phase kWh meter, three-wire, single stator self-contained meter.
Form 3 - A single phase kWh meter, two-wire, single stator, instrument rated meter.
Form 4 - A single phase kWh meter, three-wire, single stator, instrument rated meter.
Form 5 - A three phase kWh meter, three-wire, two-stator, instrument rated meter.
Form 6 - A three phase kWh meter, four-wire wye, two-stator, instrument rated meter.
Form 8 - A three phase kWh meter, four-wire delta, two-stator, instrument rated meter.
Form 9 - A three phase kWh meter, four-wire wye, three-stator, instrument rated meter.
Form 12 - A three phase kWh meter, three-wire, two-stator, self-contained meter.
Form 14 - A three phase kWh meter, four-wire wye, two-stator, self-contained meter.
Form 15 - A three phase kWh meter, four-wire delta, two-stator, self-contained meter.
Form 16 - A three phase kWh meter, four-wire wye, three-stator, self-contained meter.

An illustration of each of these forms will be made available in the next articles to come.
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