System information

36
Table 15 — PIC 5 Alarm Codes (cont)
ALARM
CODE
(ALARMRST)
ALARM TEXT
DESCRIPTION
RESET TYPE
ACTION TAKEN BY
CONTROL
POSSIBLE CAUSE
PROTECTIVE LIMITS (CONT)
Alm-253
ALM-253 Protective
Limit — High Discharge
Temperature
Manual Unit shuts down.
Check for closed compressor dis-
charge isolation valve.
Check if chiller was operating in
surge conditions.
Check compressor discharge tem-
perature sensor resistance or volt-
age drop.
Check for proper wiring to IOB con-
nectors.
Check for proper condenser flow
and temperature.
Check for proper inlet guide vane
and optional diffuser actuator oper-
ation.
Check for COMP DISCHARGE
TEMP > 220 F (104 C)
Check for fouled tubes, plugged
water strainers, or noncondens-
ables in the condenser.
Alm-254
ALM-254 Protective
Limit — Low Evaporator
Refirgerant Temperature
Manual Unit shuts down.
Check for proper refrigerant charge.
Check float valve operation.
Check for closed condenser liquid
line isolation valve.
If problem occurs at high load,
check for low condenser pressure
which causes inadequate refriger-
ant flow through condenser flasc
orifices.
Check for proper chilled water flow
and temperature.
Confirm that condenser water
enters bottom row of condenser
tubes first (reversed condenser
water flow may cause refrigerant to
stack in the condenser).
Check evaporator pressure trans-
ducer and evaporator refrigerant liq-
uid temperature and leaving chilled
water sensors.
Check for division plate gasket
bypass.
Check for fouled tubes.
Check pressure transducer and
temperature sensor wiring to the
IOB.
Alm-255
ALM-255 Protective
Limit — High Motor Tem-
perature
Manual Unit shuts down.
Check compressor motor winding
temperature sensor accuracy and
wiring to IOB.
Check motor cooling line and spray
nozzle for proper operation or
restrictions.
Check motor cooling filter/drier and
isolation valves.
Look for refrigerant flow through
motor cooling line sight glass.
Check for excessive starts within a
short time span.