Onan DYG Series Operator's Manual And Parts Catalog page 11

CONTROL PANEL INTERIOR
The only equipments discussed in this section will be
those which the operator may have reason to adjust or
inspect for service.
Terminal Board (TB) 21
Connection of wire W12 to terminals H3, H4, H5, and
H6 is made at this point, to change reference voltage
when reconnecting generator for different voltages.
Refer to Figure 16.
Voltage Regulator
Solid state unit, consisting of printed circuit board
VR21; an SCR bridge CR21, with a commutating
reactor L21 are located in the control panel as part of
the voltage regulator system. AC output from
generator is controlled at predetermined level
regardless of load; regulation is plus or minus 2
percent from no load to full load, at 0.8 PF.
CAUTION
High Engine Temperature Cutoff will shut
down engine in an overheat condition only if
coolant level is sufficiently high to physically contact shutdown
switch. Loss of coolant will allow engine to overheat without
protection of shutdown device, thereby causing severe damage to
the engine. It is therefore imperative that adequate engine coolant
levels be maintained, to ensure operational integrity of cooling
system and engine coolant overheat shutdown protection.
On standard control panels, all four alarms are wired into one
common fault lamp; on units with five fault lamps, four have
shutdown alarms, the fifth (low engine temperature) lights a fault
lamp only. Refer to Table 3.
Standard Cranking Module
Limits engine cranking time to 75 seconds. If engine
fails to start after 75 seconds the engine monitor lights
a fault lamp and opens the cranking circuit.
Engine Monitor
Printed circuit plug-in modules provide the following
functions:
1. A 75 second cranking period.
2. Approximately a 12.5-second time delay for oil
pressure buildup.
3. An external alarm contact to light a fault lamp and
shut down the set for alarm conditions such as:
a. Overcrank (failed to start after cranking 75
seconds).
b. Low oil pressure 14 psi (96.5 kPa).
c. High engine temperature 215° F (102° C).
OPTIONAL MODULES
Cycle Cranker
Plug-in module replaces standard cranking circuit.
Automatically provides a 15-second crank time and a
10-second rest time forthree ON and two OFF cycles
in 65 seconds. If engine fails to start, after 75 seconds
the engine monitor lights a fault lamp and opens the
cranking circuit. The ON and OFF cycle times are
nominal and can be adjusted at potentiometers on the
cranker module board.
Pre-Alarm
Gives advance warning for low oil pressure or high
engine temperature. Requires two sensors each for
engine temperature and oil pressure.