Mitsubishi Electronics P500YMF-C, PURY-P400 110, Once vacuum operation protection is, Drain pump

Checking code		Meaning, detecting method				Cause	Checking method & Countermeasure
1505	Suction	Judging that the state when the		•	Operation while neglecting to open		Once vacuum operation protection is
	pressure	suction pressure reaches 0kg/			ball valve. Especially for the ball		commenced, do not attempt to
	abnormality	cm2G (0MPa) during compressor			valve at low pressure side.		restart until taking the measures
		operation indicates high pressure			At cooling	: Gas side ball valve	below.
		by the discharge temperature and			At heating	: Liquid side ball valve	<Checking method>
		low pressure saturation tempera-		•	When plural systems are existing,		• Check ball valve for neglecting to
		ture, the back-up control by gas			the low pressure abruptly drop at		open.
		bypassing will be conducted.			indoor stopping by the erroneous		• Check extended piping for
					wiring of transmission line (differ-		clogging when ball valve is
					ent connection of transmission line		opened.
					and refrigerant piping).		• Check transmission line for errone-
				•	Temporary vacuum condition due		ous wiring. (Confirm the correct wir-
					to refrigerant distribution unbalance		ing and piping connection between
					(insufficient refrigerant of low pres-		indoor and outdoor units by oper-
					sure line) immediately after charg-		ating indoor unit one by one.)
					ing refrigerant.		<Countermeasure>
							• After checking with the above
							method, make error reset by
							power source reset.
							• Then operate for 10~15-minutes
							under the operation mode reverse
							to that when the vacuum opera-
							tion protection occurred (Heating
							if error occurred in cooling, while
							cooling if it occurred in heating),
							and then enter into the ordinary
							operation state.
2500	Leakage (water)	When drain sensor detects flood-		1)	Water leak due to humidifier or the		Check water leaking of humidifier
	abnormality	ing during drain pump OFF.			like in trouble.		and clogging of drain pan.
2502	Drain pump	When indirect heater of drain sen-		1)	Drain sensor sinks in water be-		Check operations of drain pump.
	abnormality	sor is turned on, rise in tempera-			cause drain water level rises due
		ture is 20 deg. or less (in water) for			to drain water lifting-up mechanism
		40 seconds, compared with the			trouble.
		temperature detected before turn-		2)	Broken wire of indirect heater of		Measure resistance of indirect heater
		ing on the indirect heater.
					drain sensor.		of drain sensor.
							(Normal: Approx. 82Ω between 1-3 of
							CN50)
				3)	Detecting circuit (circuit board)		Indoor board trouble if no other
					trouble.		problems is detected.
2503	Drain sensor	Short/open is detected during drain		1)	Thermistor trouble.		Check resistance of thermistor.
	abnormality	pump operations. (Not detected		2)	Poor contact of connector.		0˚C	Ω	10˚C	: 9.7k	Ω
								: 15k
		when drain pump is not operating.)			(insufficient insertion)		20˚C	: 6.4kΩ	30˚C	: 4.3kΩ
		Short	: 90˚C or more detected	3)	Full-broken of half-broken ther-
		Open	: -40˚C or less detected		mistor wire.
				4)	Indoor unit circuit board (detecting		Check contact of connector.
					circuit) trouble.		Indoor port trouble if no other
							problem is detected.
	Operation of	When float switch operates (point		1)	Drain up input trouble.		Check drain pump operations.
	float switch	of contact : OFF), error stop is ob-		2)	Poor contact of float switch circuit.		Check connect contact.
		served with code No. “2503” dis-
		played.		3)	Float switch trouble.		Check float switch operations.

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