Woodward 9907-252, Installation And Operation Manual

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Manual 02035 Load Sharing Module
Woodward 21
Chapter 5.
Troubleshooting
The following trouble-shooting guide is an aid in isolating trouble to the Load
Sharing Module, engine control, plant wiring, or elsewhere. The guide assumes
that the system wiring, soldered connections, switch and relay contacts, and
input and output connections are correct and in good working order. Make the
checks in the order indicated.
To prevent possible serious damage to the Load Sharing Module, do
not attempt to service the unit beyond that described in the operating
instructions. All other servicing should be referred to qualified
service personnel.
SYMPTOMS CAUSE TEST/REMEDY
Undesirable speed decrease
with load increase. Droop mode switch is open or
auxiliary contact is open. Load
Sharing Module is in droop
mode. Jumper Load Sharing Module terminals 13
and 14. If this corrects the problem, replace
wiring or switch as required. The module
will not go into droop with the terminals
connected.
Improper engine operation.
Operate the engine and
observe speed while applying
load. If droop occurs near the full load point only,
it is possible the engine is not producing the
horsepower called for or is being
overloaded.
Faulty engine control.
Disconnect the Load Sharing
Module and load the engine as
a single, isolated unit.
If speed continues to decrease with load,
engine operation may be faulty.
Erratic Load Sharing Module
operation. Open or intermittent wire. Check all wiring for continuity and tight
connections. Repair if necessary.
EMI (Electromagnetic
Interference).
Remove ground loops. Shield all wiring
(load sharing lines, output to the speed
control, speed trim pot, and SPM-A
synchronizer input. Route wiring away from
noise sources.
Unstable system. Check system for proper operation.
Unstable voltage regulator. Consult voltage regulator manufacturer’s
manual for proper adjustment.
Poor system stability. Reduce the load signal voltage of each unit
in the system to three volts.
Load Signal voltage is low.
Adjusting LOAD Gain won't
raise it. Incorrect phasing of CT and PT
wiring. Perform phasing check. If phasing check
indicates need, perform procedure for
correct phase wiring.
Insufficient CT output. Check for 5 amp CT output at full load.
Change to a lower primary current CT if
necessary.