distribution board is defined as “a component of an electricity supply system which divides an electrical power feed into subsidiary circuits, while providing a protective fuse or circuit breaker for each circuit, in a common enclosure.”

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DEFINITION OF EQUIPMENT AND PARTS.

Feeder:&nbsp. conductors that connect the power supply source and a final branch circuit over-current device.

N/C and N/O: these are the normally closed and normally open contacts respectively.

Normally closed (N/C) contact is one which is in conducting state when it or the device operating it is in a de-energized condition.

Normally open (N/O) contact is always non-conducting when it or the device operating. it is in a de-energized state. These two connect or disconnect the line from the load.

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Metering circuit breaker:

The American National Standards Institute (ANSI) defines a circuit breaker as: “A mechanical switching device, capable of making, carrying and breaking currents under normal circuit conditions. Also capable of making and carrying for a specified time and breaking currents under specified abnormal circuit conditions, such as those of a short circuit.”

The metering circuit breaker here protects the meter circuit from faults that could cause adverse effects on them. It operates by switching itself off in case of a spot. When the fault is rectified, it is switched on.

Remote emergency trip push button:

It is a switch usually located at a safer location and in this case, is used to shut down the power to the metering on emergency.

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22kV/110V VT’S – Metering Voltage Transformer:

It is a transformer used to monitor the power line voltage. This steps down line power from 22kV to 110V that can be applied to the measuring instruments without damaging them.

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400/5A, 100/5A CT’S – Metering Current Transformer:

It is a transformer used to monitor the power line current. It isolates the meters from the broad wind of the line and provides a reduced current that can be consumed by the measuring instrument.

The 400/5A reduces current from 400 amperes to 5 amperes suitable for metering instruments.

&nbsp.Likewise, 100A/5A steps down current from 100A to 5A to be used in metering.

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TX2 1000kVA 10,000/400V Transformer:

A step-down Delta/Wye transformer that converts 10kV to 400V for low voltage consumption. It has a rating of 1000kVA. The delta/wye configuration is the most commonly used in 3-phase transformers because the wye on the secondary side gives a fourth conductor, the neutral, which is useful in LV distribution. It facilitates the use of single-phase power from a 3-phase LV line.

Main Incomer:

Found on the main distribution board and it acts like a switch which is responsible for switching the phases and neutrals for the whole power supply.

6 Stage 200kVAr PFC Unit with Auto Control:

This is a power factor correction (PFC) unit with a 200kVAr rating. The control parameter is VAR and not PF (power factor). Target PF value is just used to calculate the capacitive VAR required to be added/removed to achieve the desired.