Mitsubishi Electronics MXZ-32SV service manual Troubleshooting check table, Lev

12-3. Troubleshooting check table

Note . LED indicates "00" in the normal status.

7-segment LED display	Error mode
00	Normal

❈If there is defect in the following parts(electronic control P.C. board, relay P.C. board, high pressure switches(63H1,63H2),indoor /outdoor fan motor , or indoor coil thermistor), the compressor may stop even with the display remained at “ 00 “.In any case, reset the breaker and check the above-stated parts.

Symptom		Outdoor unit does not operate.
Display	Detecting method	Detecting method	Check points
a4	Outdoor power system abnor-	When the compressor operation has been interrupted by overcurrent	• Inverter output
(A4)	mality	protection continuously three times within 1 minute after start-up, the	• Compressor
		compressor stops operation.
a3	Outdoor electronic control P.C.	When the nonvolatile memory data cannot be read properly on the out-	• Outdoor electronic control P.C. board
(A3)	board abnormality	door controller board
p1	Indoor unit and LEV abnor-	When the drain abnormality is detected in the indoor unit and the indoor	• Check the abnormality indication on the
		main coil temperature is too low, or when any abnormality is detected in	indoor unit.
(P1)	mality
		the components of indoor unit	• LEV
Symptom		Outdoor unit stops and restarts every 3 minutes.
Display	Detecting method	Detecting method	Check points
			• Check the characteristic of the evapora-
e9	Evaporation temperature ther-	The compressor stops when a short or open circuit occurs in the evap-	tion temperature thermistor. Refer to F
(E9)	mistor abnormality	oration temperature thermistor during compressor running.	on page 32.
			• Check the contact of P. C. board con-
			nectors.
			• Check the characteristic of the discharge
e6	Discharge temperature ther-	The compressor stops when a short or open circuit occurs in the dis-	temperature thermistor. Refer to F on
(E6)	mistor abnormality	charge temperature thermistor during compressor running.	page 32.
			• Check the contact of P. C. board con-
			nectors.
f8			• Check the characteristic of the fin temper-
	Fin temperature thermistor	The compressor stops when a short or open circuit occurs in the fin tem-	ature thermistor. Refer to F on page 32.
(F8)	abnormality	perature thermistor during compressor running.	• Check the contact of P.C. board connec-
			tors.
			• Check the inverter and compressor.
			Refer to E on page 31.
a8	Overcurrent protection	When over current is applied to the power module, the compressor	• Check the amount of gas.
(A8)		stops and restarts in 3 minutes.	• Check the indoor/outdoor air flow for
			short cycle.
			• Check the indoor unit air filter for
			clogging.
d6	Discharge temperature over-	When the discharge temperature thermistor detects 116˚C or above, the	• Check the amount of gas and the refriger-
		compressor stops and restarts operation in 3 minutes.	ant cycle.
(d6)	heat protection
		(Protection will be released at 100; or below.)	• Check the outdoor unit air passage.
d4			• Check the outdoor unit air passage.
	Fin temperature overheat pro-	When the fin temperature thermistor detects 89˚C or above, the com-	• Check the power module.
(d4)	tection	pressor stops and restarts operation in 3 minutes.	• Check the outdoor fan motor. Refer to G
			on page 32.
d7	High pressure protection	When the compressor starts, primary current or output voltage stops the	• Amount of gas
(d7)		compressor and restarts in 3 minutes.	• Outdoor unit air passage.
			• Check the ball valve.
f5	Room-A gas pipe temperature	When a short or open circuit occurs in the Room-A gas pipe	• Room A gas pipe temperature thermistor
			characteristic.
(F5)	thermistor abnormality	temperature thermistor.
			• Contact of P.C. board connectors.
f6	Room-B gas pipe temperature	When a short or open circuit occurs in the Room-B gas pipe	• Room B gas pipe temperature thermistor
			characteristic.
(F6)	thermistor abnormality	temperature thermistor.
			• Contact of P.C. board connectors.
f7	Room-C gas pipe temperature	When a short or open circuit occurs in the Room-C gas pipe	• Room C gas pipe temperature thermistor
			characteristic.
(F7)	thermistor abnormality	temperature thermistor.
			• Contact of P.C. board connectors.
p9	Room-D gas pipe temperature	When a short or open circuit occurs in the Room-D gas pipe	• Room D gas pipe temperature thermistor
			characteristic.
(P9)	thermistor abnormality	temperature thermistor.
			• Contact of P.C. board connectors.

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