Electric Plant Terms

Bus

It is a physical interface where many circuits share the same electrical connection

Terminal Voltage

The voltage present at the generator output terminals

Bus Tie Circuit Breaker

Breaker used to connect or disconnect one bus, such as that in a switchboard, to another bus

Generator Circuit Breaker

Breaker used to connect the generator output terminals terminals to the bus

Droop

Mode of governor operation normally used for paralleling with shore power

Synchronous

Defines a relationship between generators

Isochronous

Means that the generator is operating at the same speed, regardless of load

Rated power factor

Power factor at which a generator is designed to operate

Reverse Power

A condition under which a generator absorbs power from the bus, effectively acting as a motor

Kva Rating

is an expression of it power generating capacity

Voltage Regulation

Expressed as a percent, it is a measure of the ability of the generator to maintain its rated output voltage

Split plant

When the bus tie circuit breakers are open and each generator is supplying power to its own switchboard

Parallel Plant

When bus tie circuit breakers are closed and all generators are capable of supplying power to all loads

Single Up

Refers to an electrical plant configuration in which only one generator is connected to the bus, supplying power to all connected loads

Shifting the load

Refers to the operation of moving the electrical plant load from one generator to another