H. Discharge pressure too high
Problems and symptoms Probable cause Recommended action
Too little or too warm condenser air. Excessively warm air leaving Clean coil, check fan and motor
condenser. for proper operation.
Restricted air flow. Cuts out on high pressure control.
Excessive discharge pressure. Air or noncondensible Remove air or non condensibles.
gas in system.
J. Discharge pressure too high
Problems and symptoms Probable cause Recommended action
Bubbles in sight glass. Lack of refrigerant. Repair leak and charge.
K. Discharge pressure too high
Problems and symptoms Probable cause Recommended action
Compressor runs continuously. Excessive load on evaporator Check system.
Abnormally cold suction line; liquid a) Expansion valve opens too far. a) Adjust superheat and check
flood-back to compressor. bulb attachment.
b) Expansion valve stuck in open b) Repair or replace.
position.
L. Discharge pressure too high
Problems and symptoms Probable cause Recommended action
Bubbles in sight glass. Lack of refrigerant. Repair leak, add refrigerant.
High pressure drop across Clogged filter drier. Replace.
filter-drier.
No refrigerant flow through Expansion valve power element has Replace valve power element.
expansion valve. lost charge.
Loss of capacity. Obstructed expansion valve. Clean or replace.
Superheat too high. Too much pressure drop in Check external equaliser of
evaporator. expansion valve.
This is by no means a complete analysis of the scroll provide the background necessary for him to recognize
refrigeration system. Instead, its intention is to familiarize and accurately correct or report any developing problem.
the operator with the operation of the scroll unit and
12
Trouble Analysis
