Table 3-6 Controller Alarm Indications (Sheet 1 of 4)

 

 

 

Code

TITLE

DESCRIPTION

No.

 

 

 

 

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

AL13

Expansion Module

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

AL14

Phase Sequence

relationship is determined. If the system is unable to determine the proper rela-

tionship alarm 14 will remain active. Additiotnal information on phase detection

 

Failure - Electronic

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.

AL15

Loss Cooling

Future Expansion

 

 

 

 

Compressor Current

Alarm 16 is triggered if compressor current draw is 15% over calculated maxi-

AL16

mum for 10 minutes out of the last hour. The alarm is display only and will trig-

 

High

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

AL17

Phase Sequence

minutes and deactivate the alarm if successful. This alarm triggers failure action

 

Failure - Pressure

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

 

Discharge Pressure

Alarm 18 is triggered if discharge pressure is 10% over calculated maximum for

AL18

10 minutes within the last hour. The alarm is display only and will trigger off

 

High

when the compressor operates for one hour without overpressure.

 

 

 

 

 

 

Discharge Tempera-

Alarm 19 is triggered if discharge temperature exceeds 135_C (275_F) for 10

AL19

minutes within the last hour. The alarm is display only and will trigger off when

 

ture High

the compressor operates for one hour without over temperature.

 

 

 

 

 

 

Control Circuit Fuse

Alarm 20 is triggered by control power fuse (F3) opening and will cause the soft-

AL20

ware shutdown of all control units. This alarm will remain active until the fuse is

 

Open (24 vac)

replaced.

 

 

 

 

 

 

 

Alarm 21 is triggered by one of the fuses (F1/F2) being opened on 18 volts AC

AL21

Micro Circuit Fuse

power supply to the Controller. The suction modulation valve (SMV) will be

 

Open (18 vac)

opened and current limiting is halted. Temperature control will be maintained by

 

 

cycling the compressor.

 

Evaporator Fan Mo-

Alarm 22 responds to the evaporator motor internal protectors. The alarm is trig-

AL22

gered by opening of either internal protector. It will disable all control units until

 

tor Safety

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

AL23

Loss of Phase B

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-

AL24

Compressor Motor

gers failure action ”C” or ”D” set by function Code 29 for perishable setpoint, or

 

Safety

”D” for frozen setpoint. This alarm will remain active until compressor draws

 

 

current.

3-17

T-309

Page 41 Page 43
Page 42
Image 42
Carrier 69NT20-531-300 manual Controller Alarm Indications Sheet 1
Page 41 Page 43

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