Hobart 60CU24, Operation And Maintenance Manual With Illustrated Parts List, Page: 33 / 234

OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set
November 16, 2007
Revision 8 Chapter 1-1
Page 19
Regulated/Diagnostic J53 Connector
Voltage Adjustment, Coarse
Voltage Adjustment, Fine LDC Control
PC Board Software
Voltage Regulator PC Board
Figure 13
(7) Voltage regulator PC board [REG] (A4)
This voltage regulator PC board (see Figure 13) is designed to provide voltage regulation for a
three-phase, four-wire, 115/200-volt, 400-Hz brushless alternator. This regulator provides field
excitation power as required to meet varying alternator load conditions to hold the alternator
voltage constant. In addition, the voltage regulator PC board circuitry provides line drop
compensation. Any deviation of the alternator voltage from its set, regulated level is sensed at
the voltage regulator PC board. The sensing signal is compared to a reference signal, and, with
associated circuitry, varies the field power supplied to the rotary exciter.
a When the machine is started, and the engine is at rated speed, the rotary exciter is excited
from alternator residual magnetism through the half-wave rectifier-bridge, located on the
voltage regulator PC board assembly. As the rotary exciter voltage increases, alternator
excitation increases and the alternator voltage builds up. The sensing circuit of the voltage
regulator PC board then compares the input voltage to a reference voltage and adjusts the
field power of the rotary exciter to bring the voltage into regulation limits.