Stedi-Power Refrigeration Troubleshooting Matrix

Fan(s) will not operate
Probable Causes:	Possible Solutions:
1. Main switch open	Close switch
2. Blown fuses	Replace fuses--Check for short circuits or overload conditions
3. Defective motor	Replace motor
4. Defective Timer or defrost thermostat	Replace defective component
5. Unit in defrost cycle	Wait for completion of cycle
6. Coil is not getting cold enough	Adjust fan delay setting of thermostat. Reset thermostat

System short of capacity
Probable Causes:	Possible Solutions:
1. Product temperature high	Blocked liquid strainer--Clean
2. Plant heat loads too high	Reduce load, speed up compressor or add extra compressors and/or evaporators
3. Liquid feed valve underfeeding evaporators	Repair and reset valves
4. Faulty control circuit	Check and reset or repair--Take special note of capacity control and low suction pressure settings
5. Hot gas bypass valve faulty	Check and repair as needed
6. Low refrigerant level in receiver	Check level on sight-glass and charge system to correct level
7. Expansion valve hisses or bubbles are visible in liquid line sight-glass	Flash gas in liquid line--Add refrigerant to system
8. Short-cycling or continuous running expansion valve blocked or jammed.	Clean or replace
9. Superheat out of adjustment. Reset expansion valve and check.	Reset expansion valve and check
10. Incorrectly sized expansion valve.	Replace with correctly sized valve
11. Low refrigerant charge	Recharge, Important: Do not mix refrigerants

Suction Accumulator-- Liquid Level Low
Probable Causes:	Possible Solutions:
1. Low refrigerant charge in system	Add refrigerant to correct level
2. Refrigerant not returning from evaporator	Check and clean evaporator controls
3. Refrigerant regulating device at evaporators faulty or our of adjustment	Repair or readjust
4. Liquid level control faulty or set incorrectly	Repair or reset
5. Accumulator holding surge volume of system	Wait for refrigerant to return to evaporators
6. Refrigerant regulating device at evaporators faulty or out of adjustment	Repair or readjust

Liquid Refrigerant Pump--Noisy operation
Probable Causes:	Possible Solutions:
1. --Pump is cavitating	Install anti-vortex plates in suction line to pump or purge oil from accumulator and suction line to pump.
2. Unbalanced or damaged impeller	Repair or replace--Check usual pump faults such as mi salignment, worn bearings, etc.--Repair or replace as necessary
3. Liquid not being pumped to evaporators--Suction and discharge valves closed or installed incorrectly	Check and open or repair
4. Blocked suction strainer (if fitted)	Clean
5. Oil in pump suction	Drain
6. Low liquid pump discharge pressure Hand expansion valves to evaporators open too wide	Reset
7. Pump is cavitating	Install anti-vortex plates or check accumulator

Condenser Water Supply Fault
Probable Causes:	Possible Solutions:
1. Water inlet ball-cock jammed	Repair or replace
2. Water supply not turned on at mains	Check and turn on
3. Water supplied at low pressure	Check and contact water supply company
4. Water pump leaking	Check seal, etc., and repair or replace as applicable
5. Blocked water sprays	Clean or replace
6. Blocked strainer on inlet to pump	Clean
7. Water temperature into shell-and tube condenser too high--Blocked lines	Inspect and clean
8. Plugged tubes	Check above items on cooling tower
9. Excessive ware consumption-- Eliminators damaged or installed upside down	Replace or install correctly
10. Sump drain plug loose or missing	Tighten or install new plug
11. Sump or water boxes leaking	Check and repair
12. Water boxes on shell-and-tube condenser internally corroded allowing water bypass	Repair or replace
13. Poor air flow--Fans rotating in wrong direction.	Check rotation and motor wiring--Repair. (Note that air is drawn or sucked through and induced draft condenser but sucked through an induced draft condenser but blown through a forced draft condenser)
14. Blocked air inlet screens	Clean
15. Blocked eliminator blades or dampers--Eliminators rusted and collapsed	Clean or replace--If condenser is positioned indoors, check doors are open to give adequate air flow
16. Dust or plastic bags blocking fins	Remove large objects, brush fins and blow through with compressed air
17. Air recalculation from exhaust to inlet	Install ducting--Relocate condenser
18. Air or other non-condensable gases in system	Purge system
19. Corroded or fouled tubes or fins	Clean and renew--Check all inlet and outlet valves on both the refrigerant side and water side are fully open
20. Oil in condenser coil	Drain--Check oil return system from separator to compressor
21. Too much refrigerant in the system	Remove refrigerant until level is visible in liquid receiver sight-glass--Check fan belt drive not slipping--Check liquid refrigerant does not hold up in condenser coils (multiple condenser installations) --Check piping connections are correctly sized and installed.

Evaporator Temperature Too High
Probable Causes:	Possible Solutions:
1. Lack of refrigerant	Check strainer, liquid feed valves, expansion valves and other evaporator feed controls--Check chilled fluid or air flows--Clean, repair, reset or replace as necessary--Check liquid refrigerant pump and refrigerant level in liquid receiver--Charge if low
2. Evaporator fouled	Surface fouled by oil or product deposits--Drain oil and clean surfaces


PHONE: (678) 546-6780 FAX: (678) 546-6782
Technical Support tech@tvss.net		Stedi-Power, Inc. 5044 B U Bowman Drive, Suite 102 Buford GA 30518

General Inquiries help@tvss.net

Stedi-Power, Inc
5044 B U Bowman Drive #102
Buford, Georgia 30518
PHONE: (678) 546-6780

Room temperature too high
Probable Causes:	Possible Solutions:
1. Room thermostat set too high	Adjust thermostat
2. Superheat too high	Adjust thermal expansion valve
3. System low on refrigerant	Add refrigerant
4. Coil iced-up	Manually defrost coil

Ice accumulating on ceiling around evaporator and/or on fan guards venturi blades
Probable Causes:	Possible Solutions:
1. Defrost duration is too long	Adjust defrost termination thermostat
2. Fan delay not delaying fans a fter defrost period	Defective defrost thermostat or not adjusted properly
3. Defective defrost thermostat or Timer	Replace defective component
4. Too many defrosts	Reduce number of defrosts

Coil not clearing of frost during defrost cycle
Probable Causes:	Possible Solutions:
1. Coil temperature not getting above freezing point during defrost	Check heater operation
2. Not enough defrost cycles per day	Adjust Timer for more defrost cycles
3. Defrost cycle too short	Adjust defr ost thermostat or Timer for longer cycle
4. Defective Timer or defrost thermostat	Replace defective component

Ice accumulating in drain pan
Probable Causes:	Possible Solutions:
1. Defective heater	Reduce load or add additional equipment
2. Unit not pitched properly	Check remote bulb--Regulate superheat
3. Drain line plugged	Clear drain line
4. Defective drain line heater	Replace heater
5. Defective Timer or thermostat	Replace defective component