heatcraft-refrigeration-p h-im-79d Manual Do Utilizador

   PROBLEM

Step ACTION ITEM

IF OK

IF NOT OK

1.

Check wiring connection to the board

• Correct field wiring to the board

2.

Low Pressure Safety (LPS) Tripped:
• Check for correct refrigerant type

• Change setpoint to match refrigerant

• Check refrigerant charge

• Add more refrigerant to proper charge

• Check LPS setting

• Correct LPS setting

• Check LPS wiring

• Correct LSP wiring

• Check EEV operation (stuck?)

• Clean or replace EEV

• Check coil for icing

• Defrost coil (see 

E6

, step 2)

• Check for correct superheat reading

• Check/replace sensor or transducer

• Check for correct nozzle selection

• Replace distributor nozzle

• Check for clogged EEV inlet screen

• Replace EEV

• Check line sizing

• Correct line sizing

• Check LPS time delay relay setting

• Reset to 1 minute

• Check operation of LPS

• Replace Low Pressure Safety Switch

3.

High Pressure Safety (HPS) Tripped:
• Check for system overcharge

• Reclaim/recover excess charge

• Check for non-condensables

• Remove all non-condensables

• Check condenser fan motor and blade

• Repair or replace motor and/or blade

• Check for dirty condenser coil

• Clean condenser coil

• Check head pressure controls

• Adjust or replace faulty controls

• Check fan cycling controls

• Adjust or replace faulty controls

• Check liquid line sizing

• Correct line sizing

• Check for liquid line restrictions

• Repair line or remove restrictions

• Check operation of HPS

• Replace HPS if necessary

  

 Compressor

4.

Oil Pressure Safety (OPS) Tripped:

        Shutdown

• Check oil level in compressor

• Add oil to crankcase to minimum level

• Check oil sump screen pickup

• Clean or replace pickup screen

• Check oil pump pressure

• Replace compressor oil pump

• Check for proper piping practices

Go to

• Correct piping to minimize oil logging

• Check for low superheat (see 

E6

)

next step

• Correct per steps in 

E6

• Check operation of auxiliary relay (R6)

• Replace auxiliary relay

• Check OPS sensor

• Replace faulty OPS sensor

• Check operation of OPS

• Replace faulty OPS

5.

Compressor Module Tripped (when supplied):
• Check module

• Replace faulty module

• Check superheat at compressor inlet

• Reduce superheat (TXV adjust, etc.)

• Check compressor for overheating

• Correct overheating problem

• Check suction pressure (too low?)

• Consider crankcase pressure regulator or
  other measures

6.

Phase Loss Monitor (PLM) Tripped:
• Check presence of all phase legs

• Correct power phase problem

• Check power supply

• Correct power supply problems

• Check operation of PLM

• Replace faulty PLM

7.

Demand Cooling (when supplied):
• Check auxiliary relay

• Replace auxiliary relay

• Check demand cooling device

• Replace faulty demand cooling device

8.

Check compressor relay on board

• Replace board if relay is faulty