Master Bilt LAE Controller 80 - Manual (Page 11)

11
SERVICE INSTRUCTIONS
1. High head pressure and high back pressure:
A. Condenser coil clogged or restricted
B. Condenser fan motor defective.
C. Air discharge in rear of cabinet restricted.
2. Low back pressure and low head pressure:
A. Restriction in system.
B. Refrigerant undercharged.
C. Leak in system
3. Pressure normal – cabinet warm:
A. Coil blocked with frost (see #4).
B. Refrigerant undercharged.
C. Control set too warm.
4. Cabinet not cycling – coil blocked with frost:
A. Defective temperature controller.
B. Refrigerant overcharged.
C. Location too hot.
D. Condenser clogged.
E. Condenser fan motor defective.
5. Compressor starts and runs – but cycles on overload:
A. Low voltage
B. Relay defective.
C. Overload defective.
D. High head pressure (see #1).