Hobart 60CU20 Operation And Maintenance Manual With Illustrated Parts List page 36

OM-2226 / Operation and Maintenance Manual
60CU20 / Series 500062 / 400 Hz. Generator Set
Regulated-diagnostic switch (located on the REG)
When the REGULATED/DIAGNOSTIC switch is in the REGULATED (down) position, the
generator output voltage is regulated by the PC board for 115/200 VAC output to an aircraft.
When this switch is placed in the DIAGNOSTIC (up) position, 12 VDC is applied to the generator
exciter with the engine running at rated RPM, in order to check the operation of the generator.
This is done to determine if a particular power output malfunction is caused by a defective
generator or by a defective voltage regulator. When this switch is in the MAINTENANCE
position, no current is supplied to the generator exciter. In this condition, a low-level, unregulated
voltage of approximately 30 VAC will be produced at the generator output terminals due to the
residual magnetism of the exciter.
(6) Transformer-Rectifier PC Board [TRB] (A404) [Optional with TR]
The TRB PC Board is only used when the optional 28.5 VDC transformer-rectifier assembly is
installed. The TR monitors the output voltage, output current, controls the input and output
contactors, and monitors all fault events associated with the DC output. When a fault event does
occur the TRB relays this information to the CTL. The CTL will issue the command to the system
that fits the fault event.
May 2, 2013
Figure 11: Transformer-Rectifier PC Board
Chapter 1-1
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