Alpha Technologies ECM - Manual (Page 26)

26
TM 744-862-C0-003 Rev.C
Engine Control Module (ECM)
3.1 Alarms Classifications, continued
MAJOR ALARMS (continued):
Alternator Over-voltage (Latching)
The generator set has detected that the alternator output voltage is too
high. Depending on generator type, this likely means that the voltage
regulator or the engine speed governor has failed. Operation of the unit
has been suspended. The alarm is cleared when the Reset command is
issued or when the manual stop switch is activated.
The alternator over-voltage alarm can be triggered in any of three
ways:
1.) The generator controller can signal the ECM that an over-
voltage condition exists.
2.) A programmable threshold of 57 VDC (Hi DC Bus Level) is
exceeded for 15 seconds.
3.) A fixed threshold of 2.7V/cell is exceeded for five (5)
seconds. The programmable threshold defaults to 2.5V/cell.
Gas Hazard (Latching)
The concentration of hydrocarbon fuel in the power system’s enclosure
air space has exceeded safe limits or 10%-20% of the Lower Explosive
Limit (LEL) for more than three (3) seconds. APU operation is
suspended. The alarm is cleared when the Reset command is issued or
when the manual stop switch is activated.
Water Intrusion
Water level within the main or fuel enclosure has exceeded safe limits
for generator operation. APU operation is suspended while this alarm
is active. The alarm is reset when the water level falls below maximum
limits.
Pad Shear (Latching)
Indicates that the main or fuel enclosure has shifted from its pad
mounting position. APU operation is suspended. The alarm is reset
when the unit is returned to its original position and the reset command
is issued or when the manual stop switch is activated.
NOTE: APU will not start if Pad Shear magnet is not
correctly installed below the Pad Shear sensor.
Low Fuel Pressure (Latching - after 5 activations)
Indicates that site fuel supply (Propane-fueled APU only) is
insufficient for extended engine operation. The alarm is reset 5 minutes
after the fuel supply is replenished.