Cooline PT036, PT360 manual Trouble Shooting Chart, Symptom Causes Check & Corrective Measure

TROUBLE SHOOTING CHART

SYMPTOM		CAUSES	CHECK & CORRECTIVE MEASURE
Thermostat shows no display	1. Power off/Blown fuse		1. Check the power. Switch ON the circuit breaker.
				Replace fuse if it blown.
	2.	Faulty field wiring	2. Check wiring against diagram.
	3.	Loose connections	3. Check and correct it.
	4.	Defective thermostat	4.	Replace it.
Thermostat LCD panel display is not	1.	Battery life is over	1. Replace battery
bright & does not function properly
Blower not running, compressor short	1. Blower belt slipped/not fixed		1. Correct belt. Check tension and alignment.
cycles	2. Faulty wiring		2. Check wiring against diagram.
	3.	Burned wiring	3. Check and correct it.
	4.	Defective blower motor contactor	4.	Replace if.
	5.	Defective blower motor	5.	Replace it.
Blower running, no sufficient air	1. Wrong rotation (Applicable initial start up/or after		1.	Check the rotation of blower, interchange phase
		a power failure), 3 phase motor		of blower motor from blower motor contactor.
Blower running, but with not enough	1. Loose Belt		1. Adjust it & check belt tension.
supply air	2. Variable pulley wide open		2. Adjust the pitch of the pulley.
	3.	Return air obstructed	3. Check and remove the obstructions.
	4.	High static pressure	4. Verify static pressure and fan performance data.
	5.	Improper pulley selection	5.	Change pulley (if blower motor ampere within rated load).
	6.	Closed dampers/improper air balance	6.	Check all dampers opened properly. Balance air.
	7.	Dirty filter	7.	Clean it.
	8.	Dirty cooling coil	8.	Clean it.
Blower running and delivers excess	1. Variable pulley needs more tightening		1. Adjust the pitch of the pulley.
air	2. Improper pulley/motor selection		2. Select suitable combination.
	3.	Low external static pressure	3. Check the duct design.
Blower runs, compressor not working	1. Safety circuit open due to low suction pressure,		1.	Re-set the unit and determine the reason. Check
		high discharge pressure, overload protector		high & low pressure (refer to symptom for "low/
				high suction pressure & high discharge pressure").
	2.	Defective compressor contactor	2.	Replace it.
	3.	Burned wiring	3. Check and replace it.
	4.	Defective compressor	4. Replace it.
Compressor runs, but short cycling	1. Safety circuit open due to:		1. a) Verify the reason for low suction pressure
		a) Low suction pressure		(refer to symptom for "low suction pressure").
		b) High discharge pressures		b) Verify the reason for high discharge pressure
				(refer to symptom for "high discharge pressure").
		c) Overload protector		c) Check dome temperature. RLA each phase.
				Verify the reason.
	2.	Thermostat in cold location	2. Check and relocate as required.
	3.	High thermostat setting	3.	Lower the temperature setting to 210C for test.
Thermostat shows faulty indication	1. Safety circuit open due to:		1. a) Verify the reason & correct it (refer to symptom
				for "low suction pressure").
		a) Low pressure switch
				b) Verify the reason for high discharge pressure.
		b) High pressure switch
				(refer to symptom for "high discharge pressure").
		c) Overload protector		c) Check comp. RLA against nameplate for each phase,
				check comp. dome temperature, etc. & correct it.
Low suction pressure	1. Less Freon		1.	Check for gas leak & charge freon as required.
	2.	Loose belt	2.	Adjust it. Check belt tension.
	3.	Variable pulley widely open	3. Adjust the pulley.
	4.	Dirty filter	4.	Clean it.
	5.	Dirty cooling coil	5.	Clean it.
	6.	Return air restricted	6.	Check return air grille sizes, etc. against design.
	7. Improper expansion valve bulb installation/location		7.	Verify and correct it.
	8. Restriction in expansion valve/filter dryer		8. Check and correct/replace it.
High suction pressure	1. Excess freon charge		1. Verify and adjust it.
	2.	Excess air quantity	2.	Adjust air quantity.
	3.	High room temperature condition	3.	Check & verify. Isolate the area to be cooled & observe.
	4.	Undersize unit (serving large area)	4. Check design/unit selection.
	5. Expansion valve widely open		5. Check superheat & adjust it, if required.
	6. Defective compressor valve		6. Check and replace compressor.
High discharge pressure	1. Condenser fan motor not working properly		1.	Fan blade stuck with ventury. Check & correct it.
	2.	Excess freon charge	2. Check freon and adjust it, if necessary.
	3.	Dirty condenser	3.	Clean it.
	4. High ambient condition/Air in condenser obstructed		4.	Verify the reason and correct it.
	5.	Defective fan motor capacitor	5. Check and replace it.
	6.	Defective fan motor	6. Check and replace it.

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