Filter
Top Products
33
ALARM CODE DESCRIPTIONS
Code Alarm name Description Action Pumpdown Reset type Probable cause
1 Evaporator leaving water thermistor fault Thermistor outside range Unit shut down Yes Auto Thermistor or wiring fault or
bad connection
2 Evaporator entering water thermistor fault Ditto Unit shut down Yes Auto Ditto
3 Condenser leaving water thermistor fault Ditto Heating mode: Unit shut down, Yes Auto Ditto
if control on leaving water.
Cooling mode: no action
4 Condenser entering water thermistor fault Ditto Heating mode: Unit shut down, - Auto Ditto
if control on entering water.
Cooling mode: no action
5 Heat reclaim entering water thermistor fault Ditto Unit with heat recalaim option: - Auto Ditto
heat reclaim mode shut down,
unit changes over to standard
cooling mode. If not: no action
6 Heat reclaim leaving water thermistor fault Ditto None - Auto Ditto
7 Outdoor temperature sensor fault Ditto Reset: normal setpoint used. - Auto, if temp. mea- Thermistor faulty
Limitation or reset deactivated. sured by sensor
returns to normal
8 CHWS (master/slave) fluid thermistor fault Ditto Deactivated - Ditto Themistor faulty
9 Suction thermistor fault, compressor A1 Ditto Circuit A shut down Yes Auto Ditto
10 Suction thermistor fault, compressor B1 Ditto Circuit B shut down Yes Auto Ditto
11 External 0-10 V dc signal fault Reset signal outside range Reset: normal setpoint used No Auto Signal incorrect, wiring error
Limitation or reset deactivated
12 Discharge pressure sensor fault, circuit A Voltage transmitted by incorrect sensor Circuit A shut down Yes Auto Sensor fault or wiring error
13 Discharge pressure sensor fault, circuit B Ditto Circuit B shut down Yes Auto Ditto
14 Suction pressure sensor fault, circuit A Ditto Circuit A shut down No Auto Ditto
15 Suction pressure sensor fault, circuit B Ditto Circuit B shut down No Auto Ditto
16 Oil pressure sensor fault, compressor A1 Ditto Circuit A shut down No Auto Ditto
17 Oil pressure sensor fault, compressor B1 Ditto Circuit B shut down No Auto Ditto
18 Oil pressure sensor fault, compressor A2 Ditto Compressor A2 shut down - Auto Ditto
19 Oil pressure sensor fault, compressor B2 Ditto Compressor B2 shut down - Auto Ditto
20 Oil pressure sensor fault, compressor A3 Ditto Compressor A3 shut down - Auto Ditto
21 Oil pressure sensor fault, compressor B3 Ditto Compressor B3 shut down - Auto Ditto
22 Oil pressure sensor fault, compressor A4 Ditto Compressor A4 shut down - Auto Ditto
23 Oil pressure sensor fault, compressor B4 Ditto Compressor B4 shut down - Auto Ditto
24 Pumpdown pressure sensor fault, circuit A Ditto If circuit is in heat reclaim - Auto, if press. mea-
mode, it goes to cooling mode. sured by sensor
If not, no action returns to normal
25 Pumpdown pressure sensor fault, circuit B Ditto Ditto - Ditto Ditto
26 Loss of communication with compressor board A1 Communication with the compressor Circuit A shut down No Auto Wiring fault, faulty module,
board is lost incorrect module address
27 Loss of communication with compressor board A2 Ditto Compressor A2 shut down No Auto Ditto
28 Loss of communication with compressor board A3 Ditto Compressor A3 shut down No Auto Ditto
29 Loss of communication with compressor board A4 Ditto Compressor A4 shut down No Auto Ditto
30 Loss of communication with compressor board B1 Ditto Circuit B shut down No Auto Ditto
31 Loss of communication with compressor board B2 Ditto Compressor B2 shut down No Auto Ditto
32 Loss of communication with compressor board B3 Ditto Compressor B3 shut down - Auto Ditto
33 Loss of communication with compressor board B4 Ditto Compressor B4 shut down - Auto Ditto
34 Loss of communication with EXV board Ditto Unit shut down No Auto Wiring bus faulty, incorrect
address or board faulty
35 Loss of communication with NRCP board The board does not respond Unit shut down, if heat reclaim mode No Auto, if board is NRCP board faulty
is selected again detected
36 Loss of communication with fan board 1 Ditto Unit shut down, if the number of No Auto Wiring bus faulty, incorrect
fan stages per circuit is less than 3. address or board faulty
If not, circuit A shut down
37 Loss of communication with fan board 2 Ditto Circuit B shut down No Auto Ditto
38 Loss of communication with 4xAI - 2xAO board 1 Ditto Unit shut down or no action No Auto Ditto, depending on
configuration
39 Loss of communication with 4xAI - 2xAO board 2 Ditto Compressors or circuit shut down No Auto Ditto, depending on
configuration
40 Pumpdown fault, circuit A End of pumpdown conditions not Circuit A shut down No Manual EXV or sensor faulty
satisfied
41 Pumpdown fault, circuit B Ditto Circuit B shut down No Manual Ditto
42 Evaporator frost protection Unit operating: units shut down if Unit shut down No Auto first time, Low water flow or
temp. < defrost threshold. then manual thermistor defective
Unit shut down: if temp < threshold
and evaporator heater on for more
than 10 mins.
43 Low evaporator water flow rate. Unit shut down No Manual Water pump faulty
44 Low suction temperature, circuit A Circuit operating: saturated suction Circuit A shut down No Manual Low charge, filter dirty
temp. < defrost threshold and < leaving ot thermistor faulty
water -16°C for more than 10 mins.
45 Low suction temperature, circuit B Ditto Circuit B shut down No Manual Ditto
46 High suction overheat, circuit A EXV fully open Circuit A shut down Yes Manual Ditto
47 High suction overheat, circuit B Ditto Circuit B shut down Yes Manual Ditto
48 Low suction overheat, circuit A EXV in min. position, and circuit Circuit A shut down Yes Manual EXV or thermistor or
superheat below superheat setpoint transducer defective
-5.5 K, saturated suction temp. above
MOP for 5 mins.
6.4 - Alarm codes
The following list gives a complete description of each alarm
code and its possible cause.