Energy Tech Laboratories DSH Manuale Utente

FORM 145.32-IOM1 (908)

JOHNSON CONTROLS

Green “POWER” 

Module has power 

Supply voltage is present at module terminals

1. Compressor protector is open                                                    

2. Condensing unit power disconnect is open 

3. Compressor circuit breaker or fuse(s)  is open

4. Broken supply wires or connector is not making contact            

5. Compressor power wires not routed 

     through Comfort Alert 
6. Compressor contactor has failed open

Red “TRIP” LED 

Flashing

1. Compressor contactor coil shorted. 

2. Electrical load too high for PROT circuit 

    (maximum 1 Amp) 
3. 24 VAC wired directly to PROT terminal 

1. High head pressure 

2. Condenser coil poor air circulation (dirty, 

     blocked, damaged) 
3. Condenser fan is not running 

4. If low pressure switch is open:

    Refer to Code 3 for troubleshooting 
1. If low pressure switch is open:

  a. Low refrigerant charge

  b. Evaporator blower is not running

  c. Evaporator coil is frozen

  d. Faulty metering device

  e. Condenser coil is dirty

   f. Liquid line restriction (?lter drier                         

      blocked if present) 

2. If high pressure switch is open, go to 

    Flash Code 2 information 

3. Intermittent thermostat demand signal 

4. System or control board defective 

Yellow “ALERT” 

Flash Code 3 

Short Cycling 

Compressor is running only 

brie?y LOCKOUT 

Red “TRIP” LED 

On Solid

Thermostat demand signal Y 

is present, but the 

compressor is not running 

Yellow “ALERT” 

Flash Code 2 

System Pressure Trip 

Discharge pressure out of 

limits or compressor over-

loaded (if no high pressure 

switch in system) 

LOCKOUT 

The anti-short cycle timer (3 minutes), in module is preventing compressor restart. 

Module locks out compressor when compressor damaging ALERT codes appear.                                                 

Lockout ALERT codes are noted in the Status LED Description.                                                                                 

During a compressor lock out, 24VAC power must be removed from module to manually reset 

A short circuit or over current 

condition exists on PROT 

terminal.

Yellow "ALERT" 

LED On Solid

briefly

(filter drier