Carrier Vector 1550-11 - BOX TEMP OUT-OF-RANGE (Continued)

62-61753-21
7-35
Alarm
NO.
Steps
ALARM / CAUSE
CORRECTIVE ACTION
53 BOX TEMP OUT-OF-RANGE (Continued)
1
Check Refrigerated Compartment Doors
a. Inspect all box doors.
Must be closed, no air leakage.
2
Defrost Evaporator
a. Initiate Manual Defrost Cycle.
Must terminate automatically.
All ice cleared from all evaporator coils.
3
Check For Any Shutdown Alarm(s)
a. Check the Alarm List for any Shut-
down Alarms.
Alarm conditions must be corrected and the alarm
cleared to continue.
4
Check For Low Refrigerant Pressure Alarm
a. Check for alarm 18.
Alarm conditions must be corrected and the alarm
cleared to continue.
5
Check Refrigerant Charge
a. Check refrigerant level in the re-
ceiver.
Generally, level should be between upper & lower sight
glasses with a refrigerated compartment temperature
of 1.0°C (35°F) or lower. refer to Section 8.5.4
6
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 evapora-
tor (EVOP) pressure readings have a maximum
value of 7.5 bar (100 psig). The actual suction pres-
sure must be lower in order to perform this test.
7
Check Evaporator Section
a. Check evaporator section, return
air bulkhead, air chute, cleanliness
of evap. coil and airflow.
Refer to Section 9.4.10
8
Perform Pretrip Check
a. Clear Active Alarm list, then run
Pretrip & check for any new
alarms.
Any active alarms must be corrected and cleared be-
fore proceeding.
9
Check For Low Delta-T
a. Read Delta-T from Unit Data List.
In Cool, the Delta-T reading must be greater than -
0.56°C (-1°F).
Note for Delta-T readings a higher number after the "-"
sign is "greater than". For example, -3°C is greater
than -2°C.
In Heat the Delta-T must be greater than 0 (SAT must
be higher than RAT).