7
−
70
62-11389
Alarm
NO.
Steps
Alarm/Cause
Corrective Action
127
CHECK SUCTION TEMP SENSOR
•
TRIGGER–ON: Compressor Suction Temperature Sensor (CST) is not within the range of -53 to
+158
°
F (-47 to +70
°
C.)
•
UNIT CONTROL: Engine and Standby Operation: alarm only.
•
RESET CONDITION: Auto Reset or alarm may be manually reset via keypad or by turning the unit
off, then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the active
alarm should clear itself (see reset condition above). Operate the unit through the appropriate modes to see if
any active alarm occurs. Continue with the steps below as necessary.
1
Check Sensor
a. Inspect sensor & connector
No damage to sensor
No damage, moisture, or corrosion in connector
b. Check sensor resistance (See
Note 3, page 7
−
2.)
10,000 Ohms @ 77
°
F (25
°
C.) See Table 8
−
5 for
complete table of temperatures and resistance
values.
2
Check Sensor Wiring
a. Inspect harness & control box
connector pins & terminals. (1MP,
see wiring schematic Section 10.)
No physical damage to harness.
No damage, moisture, or corrosion in connectors.
b. Power up the microprocessor (see
Note 2 page 7
−
2). Disconnect
sensor from harness. Check for
2.5 VDC at harness plug between
pins.
Voltage should be 2.5 VDC volts at harness plug be-
tween pins. This verifies microprocessor output and
wiring connections to sensor.
128
LOW/UNBALANCED A/C AMPS
•
TRIGGER–ON: The compressor is on and AC Current Sensor 1 or 2 is less than 5 amps for 10
seconds OR If the difference between AC Current 1 and AC Current 2 is greater than 10 amps for
10 seconds.
•
UNIT CONTROL: Engine and Standby Operation: alarm only.
•
RESET CONDITION: Change unit to Standby Operation when AC Current Sensor 1 and 2 is great-
er than 7 amps for 5 minutes AND difference between AC Current 1 and AC Current 2 is less than
7 amps for 5 minutes OR alarm may be manually reset via keypad or by turning the unit off, then
back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the active
alarm should clear itself (see reset condition above). Operate the unit through the appropriate modes to see if
any active alarm occurs. Continue with the steps below as necessary.
1
Perform Pretrip Check
Clear Active Alarm list, then run Pre-
trip & check for any new alarms.
Any active alarms must be corrected and cleared
before proceeding.
2
Check Current Draw
a. Use a clamp around A/C ammeter
to check amps at power wires.
Must be
"
1.0 Amp of reading in Data List.
b. Check A/C amps with compressor
running.
Must be greater than 5 Amps.
c. Compare A/C Amp readings
between L1-L2-L3.
Maximum allowable difference is 10 Amps.
