TM 9-6115-729-24
0011
TROUBLESHOOTING FAILURES WITHOUT FAULT CODES - Continued
CAUTION
If low voltage occurs when load is first connected, excessive motor-starting currents in load may
be the fault. Compressor starting currents may be too great for generator set. Air conditioner,
refrigerator, and freezer compressor motors often require 5 to 10 times their rated current during
start-up. If all of these loads are started at the same time, generator overload is possible.
SYMPTOM
11.
Generator Produces Low Voltage When Load is Applied.
MALFUNCTION
DVR Malfunction.
CORRECTIVE ACTION
STEP 1.
Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to NORMAL.
On EMCP set ENGINE CONTROL switch to START.
STEP 2.
Monitor current at instant of load connection. Current should be less than rated
current and the same in each leg.
STEP 3.
If current is too close to rated current, generator is being overloaded. Reduce
load or add another generator set in parallel.
STEP 4.
Check current in each leg of output.
STEP 5.
If current is not equal in all legs, selectively turn off loads until balanced.
STEP 6.
Reconfigure loads as necessary or check for load failure.
STEP 7.
Measure voltage at load connection terminals. Measure voltage at load.
STEP 8.
If voltage drop from generator to load is more than 10%, increase wire size
between generator set and load.
STEP 9.
Check DVR parameter :30 (droop percentage). Voltage should not drop lower
than the droop percentage will allow.
a. If output goes lower than the droop percentage allows, on EMCP set
ENGINE CONTROL switch to OFF/RESET. Set Battery Disconnect Switch to
OFF. Set DEAD CRANK SWITCH to OFF.
b. Replace DVR (WP 0041 Guide) and retest system.
c.
If DVR replacement does not resolve problem, replace generator (WP 0097).
STEP 10.
Verify the problem has been resolved.
0011-14
