If operated in parallel with a generator already
To place the voltage regulator in control for the first
time, you should perform the following steps:
connected to the bus, close the circuit breaker of the
incoming generator only when the two outputs are
synchronized. The incoming generator can be
connected to the line with the regulator control switch
in the NORMAL or AUTOMATIC position. As soon as
the two generators are operating in parallel, readjust the
governor motor (speed-changer) until each unit takes its
share of the kilowatt load.
To shut down the unit, remove the kilowatt load on
the generator by turning the governor motor control
rheostat while observing the wattmeter. If necessary
turn the voltage adjusting rheostat in a direction to
reduce the reactive load. As the load approaches zero,
open the generator line circuit breaker.
In addition to the actions shown on the maintenance
requirement cards and the instructions given in the
voltage regulator technical manuals, routine
maintenance should include ensuring that connections
are tight and strictly in accordance with installation
diagrams. This maintains the effective resistance in the
shunt field circuit of the exciter. You should also ensure
that the operation of the silver buttons is smooth
throughout the entire travel of the movable core.
It would be advisable to review the information
To place the regulator in control of the ac generator
about silver contacts in chapter 6, Motor Controllers.
voltage, you should perform the following steps:
Contacts made of silver or its alloys conduct current
when discolored (blackened during arcing) with silver
oxide. This discolored condition therefore requires no
filing, polishing, or removing.
ROTARY AMPLIFIER VOLTAGE
The rotary amplifier (amplidyne) type of voltage
regulator uses a special type of exciter. It finishes a
large change in output voltage for a small change in the
control field current of the exciter. The control element
detects variation of the ac generator voltage from a
reference voltage. This can be set to a predetermined
value. The variation between the actual alternating
voltage and the reference voltage sends a current
through the control field of the exciter. This changes its
output voltage current and hence, changes the ac
generator field current. This holds the alternating
voltage at the desired value.
The complete amplidyne voltage regulator
equipment consists of the following components: