Thermostatic Expansion Valve Malfunction; Power Autotransformer Malfunction; Water-Cooled Condenser Or Water Pressure Switch - Carrier 69NT40-511-1 Operating And Service Manual

CONDITION

5.11 THERMOSTATIC EXPANSION VALVE MALFUNCTION

Low suction pressure with high
superheat
High suction pressure with low
superheat
Liquid slugging in compressor
Fluctuating suction pressure

5.12 POWER AUTOTRANSFORMER MALFUNCTION

Unit will not start

5.13 WATER-COOLED CONDENSER OR WATER PRESSURE SWITCH

High discharge pressure
Condenser fan starts and stops
T-268-07
POSSIBLE CAUSE
Low refrigerant charge
External equalizer line plugged
Wax, oil or dirt plugging valve or orifice Ice formation at
valve seat
Superheat too high
Power assembly failure
Loss of element/bulb charge
Broken capillary
Foreign material in valve
Superheat setting too low
External equalizer line plugged Ice holding valve open
Foreign material in valve
Pin and seat of expansion valve eroded or held open by
foreign material
Improper bulb location or installation
Low superheat setting
Circuit breaker (CB-1 or CB-2) tripped
Power transformer defective
Power source not turned ON
460 VAC power plug is not inserted into the receptacle
Dirty coil
Noncondensibles
Water pressure switch malfunction
Water supply interruption
5-4
REMEDY/
REFERENCE
SECTION
6.4/6.6
Open
6.26
6.4/6.6
6.26.c
6.26
6.26
6.26
6.26.c
Open
6.4/6.5 6.26
6.26
6.26
6.26.c
Check
6.22
Check
2.4
6.28
Check