Rheem PNL-*AZ Series Installation Instructions Manual page 28

LOSS OF LUBRICATION
SYMPTOMS
Compressor failures
Low suction pressure
Cold, Noisy compressor - Slugging
Noisy compressor
Cold, sweating compressor
Low Load
Short cycling of compressor
FLOODED STARTS
SYMPTOMS
Liquid in the compressor shell
Too much liquid in system
SLUGGING
SYMPTOMS
On start up
TEV hunting when running
FLOODING
SYMPTOMS
Poor system control
using a TEV
Poor system control
using capillary tubes
28
POSSIBLE CAUSE
Line tubing too long
Line tubing too large
Low charge
Refrigerant leaks
Dilution of Oil with Refrigerant
Migration
Flooding
Reduced air flow
Thermostat setting
Faulty pressure control
Loose wiring
Thermostat
POSSIBLE CAUSES
Faulty or missing crankcase heater
Incorrect piping
Overcharge
POSSIBLE CAUSES
Incorrect piping
Oversized TEV
POSSIBLE CAUSES
Loose sensing bulb
Bulb in wrong location
Wrong size TEV
Improper superheat setting
Overcharge
High head pressures
Evaporator air flow too low
CHECK OR REMEDIES
Add oil to the recommended level
Reduce pipe size to improve
oil return
Check system charge
Repair and recharge
Observe piping guidelines
Check crankcase heater
Check system charge
Dirty filter
Dirty coil
Wrong duct size
Restricted duct
Advise customer
Replace control
Check all control wires
In supply air stream,
out of calibration,
Customer misuse
CHECK OR REMEDIES
Replace crankcase heater
Check Piping guidelines
Check and adjust charge
CHECK OR REMEDIES
Review pipe size guidelines
Check TEV application
CHECK OR REMEDIES
Secure the bulb and insulate
Relocate bulb
Use correct replacement
Adjust, if possible;
Replace, if not
Check system charge
Dirty heat pump
Restricted air flow
Recirculation of air
Adjust air flow to 350-400 CFM/Ton