Carrier Vector 1550-11 - High Discharge Pressure

62-61753-21
7-7
Alarm
NO.
Steps
ALARM / CAUSE
CORRECTIVE ACTION
13 HIGH DISCHARGE PRESSURE
 TRIGGER-ON: Compressor discharge pressure is over 31.6 bar (465 psig)
 UNIT CONTROL: Engine operation: Unit shutdown and alarm.
Standby operation: Refrigeration system shutdown and alarm with PSCON
still energized.
 RESET CONDITION: Auto Reset after 15 minutes if the compressor discharge pressure falls below
23.8 bar (350 psig), 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 (refer to 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 System Pressures
a. Install Manifold Test Set and check
and compare compressor dis-
charge & suction pressures with
those shown on the microproces-
sor.
Suction & Discharge Pressures must have the same
reading on gauges & on microprocessor display.
Pressures must be in the normal range for ambient &
refrigerated compartment temperature conditions.
NOTE: Microprocessor suction (CSP) and evaporator
(EVOP) pressure readings have a maximum value of
7.5 bar (100 psig). The actual suction pressure must
be lower in order to perform this test.
2
Check For Refrigerant Overcharge
a. Check refrigerant level in the re-
ceiver.
Generally, level should be between upper & lower sight
glasses with a refrigerated compartment temperature
of 1.0C (35°F) or lower, refer to Section 8.5.4
3
Check Airflow Through Radiator / Condenser Coil
a. Inspect condenser / radiator fins.
Fins must be straight. 90% or more of the coil surface
must be undamaged. No "dead" air spaces. Condenser
/ Radiator coil must be clean (refer to Section 8.6.3).
b. Check airflow.
Even airflow through the entire coil. No "dead" spots.
c. Check condenser fan rotation /
operation.
Fans should operate correctly. Air should be drawn in
through the grill, and directed into the engine com-
partment.
4
Check Switch Wiring
a. Inspect switch & connector pins &
terminals. (See wiring schematic
Section 10.)
No physical damage to harness.
No damaged or corroded pins.
b. Check switch circuit
Check for voltage at the switch
plug between pins A (+) and B
(ground).
Energize circuit (refer to Note 2 Page 7-2).
Voltage should be approximately 12 VDC.
5
Check High Pressure Switch
d. Check switch operation.
Refer to Section 8.6.11.
6
Perform Pretrip Check
a. Clear Active Alarm list, then run
Pretrip & check for alarms.
Any active alarms must be corrected and cleared be-
fore proceeding.
7
Refer to Abnormal Pressure Trou-
ble Shooting Section 9.4.7.
Discharge Pressure must be in normal range for the
current ambient and refrigerated compartment temper-
ature conditions.