Table 3-6 Controller Alarm Indications - Carrier Streamline Scroll 69NT20-531-300 Operation & Service Manual

Code
TITLE
No.
AL13 Expansion Module
AL14 Phase Sequence
Failure - - Electronic
AL15 Loss Cooling
AL16 Compressor Current
High
AL17 Phase Sequence
Failure - - Pressure
AL18 Discharge Pressure
High
AL19 Discharge Tempera-
ture High
AL20 Control Circuit Fuse
Open (24 vac)
AL21 Micro Circuit Fuse
Open (18 vac)
AL22 Evaporator Fan Mo-
tor Safety
AL23 Loss of Phase B
AL24 Compressor Motor
Safety
Table 3-6 Controller Alarm Indications (Sheet 1 of 4)
Alarm 13 is triggered if the control module has lost communication with the ex-
pansion module for more than five minutes or communication fails within the
first 15 seconds on power up. This alarm triggers failure action C (evaporator fan
only) or D (all machinery off) of Function Code Cd29 if the unit has a perishable
set point. Failure action D (all machinery off) is triggered if the unit has a frozen
set point
Alarm 14 is triggered if the electronic phase detection system is unable to deter-
mine the correct phase relationship. DIRCHECK will be displayed while the
relationship is determined. If the system is unable to determine the proper rela-
tionship alarm 14 will remain active. Additiotnal information on phase detection
may be displayed at Function Code Cd41. If the right most digit of Code Cd41 is
3 or 4, this indicates incorrect motor or sensor wiring. If the right most digit is 5,
this indicates a failed current sensor assembly.
Future Expansion
Alarm 16 is triggered if compressor current draw is 15% over calculated maxi-
mum for 10 minutes out of the last hour. The alarm is display only and will trig-
ger off when the compressor operates for one hour without over current.
Alarm 17 is triggered if a compressor start in both directions fails to generate
sufficient pressure differential. The controller will attempt restart every twenty
minutes and deactivate the alarm if successful. This alarm triggers failure action
C (evaporator fan only) or D (all machinery off) of Function Code Cd29 if the
unit has a perishable set point. Failure action D (all machinery off) is triggered if
the unit has a frozen set point
Alarm 18 is triggered if discharge pressure is 10% over calculated maximum for
10 minutes within the last hour. The alarm is display only and will trigger off
when the compressor operates for one hour without overpressure.
Alarm 19 is triggered if discharge temperature exceeds 135_C (275_F) for 10
minutes within the last hour. The alarm is display only and will trigger off when
the compressor operates for one hour without over temperature.
Alarm 20 is triggered by control power fuse (F3) opening and will cause the soft-
ware shutdown of all control units. This alarm will remain active until the fuse is
replaced.
Alarm 21 is triggered by one of the fuses (F1/F2) being opened on 18 volts AC
power supply to the Controller. The suction modulation valve (SMV) will be
opened and current limiting is halted. Temperature control will be maintained by
cycling the compressor.
Alarm 22 responds to the evaporator motor internal protectors. The alarm is trig-
gered by opening of either internal protector. It will disable all control units until
the motor protector resets and the unit is power cycled.
Alarm 23 is triggered if low current draw is detected on phase B and IPCP, HPS
or IPEM is not tripped. If the compressor should be running, the controller will
initiate a start up every five minutes and trigger off if current reappears. If the
evaporator fan motors only should be running, the alarm will trigger off is cur-
rent reappears. This alarm triggers failure action C (evaporator fan only) or D
(all machinery off) of Function Code Cd29 if the unit has a perishable set point.
Failure action D (all machinery off) is triggered if the unit has a frozen set point
Alarm 24 is triggered when compressor is not drawing any current. It also trig-
gers failure action "C" or "D" set by function Code 29 for perishable setpoint, or
"D" for frozen setpoint. This alarm will remain active until compressor draws
current.
DESCRIPTION
3-17
T-309