Toshiba MMU-AP0151MH, MMU-AP0181MH, MMU-AP0091MH Clogging check for oil-equalization circuit, H08

(*3) Check for solenoid valve of outdoor unit (For multiple outdoor unit system)

a)Clogging check for SV3A valve

•While outdoor unit is operating, set up SW01/02/03 = [2] [1] [3] to 7-segment display [Hr] [ 2], and push SW04 for 2 seconds or more.

•Set up SW02 = [4], and turn on SV3A valve. (7-segment display [Hr] [ 3A])

•If temperature is low at secondary side of the valve or it does not change, clogging of valve or check valve is considered. (• in the figure.)

b)Leakage check for SV3C valve

•While outdoor unit is operating, set up SW01/02/03 = [2] [1] [3] to 7-segment display [Hr] [ 2], and push SW04 for 2 seconds or more.

•Set up SW02 = [6], and turn on SV3C valve. (7-segment display [Hr] [ 3C])

•If temperature does not change (up), clogging of valve or strainer is considered. (‚ in the figure.)

(*4)

a)Clogging check for oil-equalization circuit

•Drive the outdoor unit. (Drive both compressors in the unit.)

•After driving for 10 minutes, check temperature of TK1 and TK2 sensors and temperature of oil-equalization circuit capillary (‡ in the figure) were raised.

(Criterion)

TK1, TK2=Td1, Td2 temperature – Approx. 10 to 30°C

Oil-equalization capillary tubes should be higher sufficiently than outside air temperature and suction temperature.

•If temperature is low, a malfunction of capillary, strainer, or check valve is considered. Repair the defective parts.

Check code name	Check code name		Cause of operation
[H08]	Oil level detective	TK1 to TK4 sensor Open/Short
	temperature sensor error
Auxiliary code : 01: TK1 sensor error 02: TK2 sensor error 03: TK3 sensor error 04: TK4 sensor error
The detected error is an oil level detective temperature sensor error.
			Circuit	Connector
Check disconnection of the wiring and resistance value of the sensor.
			TK1	CN514 (Black)
If the sensors are normal, replace the outdoor I/F P.C. board.
			TK2	CN515 (Green)
			TK3	CN516 (Red)
			TK4	CN523 (Yellow)
Check code name	Check code name		Cause of operation
[H16]	TK1 temperature detective circuit error	1. Coming-off of TK1 sensor, miscabling,
	(Auxiliary code : 01)	characteristics error of resistance value
		2. Oil-equalization circuit error
		(Check valve, capillary clogging,
		strainer clogging)
		3. Refrigerant stagnation in case of
		compressor shell

76

	High-pressure
5	sensor
	Check joint
	(SV2)
	Oil
	separator

	(SV3D)	Solenoid valve
	Solenoid valve
		(SV42)
6	(SV41)
	High-pressure	High-pressure
	SW	SW

(TD1)					Sensor
					(TD2)
1				2	2
		Sensor
Compressor	(Inverter)			Compressor	(Inverter)
		(TK3)
		Strainer	Strainer
		(TK1)	(TK2)
		(TK4)	Oil tank
(SV3E)					7
4

Is not TK1 sensor detached?		YES
	NO
		YES
Is there no miscabling or misinstallation
on TK1/TK2/TK3/TK4 sensors?		* Characteristics-4
	NO
Are characteristics of TK1 sensor		NO
resistance value normal?		* Outdoor unit temp sensor characteristics-4
	YES
			Error

Start a test operation in COOL or HEAT mode.

TK1 sensor temp is displayed on 7-segment display with SW01/02/03=[1] [11] [2].

Check TK1 sensor temp approx. 10 minutes after compressor 1 has operated. If low temperature continues (approximately outside temp) or temperature does not almost change, a clogging of strainer of oil-equalization circuit, clogging of capillary tube, or malfunction of check valve is considered.

No error

Correct installation of sensor.

Correct miscabling/misinstallation.

TK1: CN514

( TK2: CN515 )

TK3: CN516

TK4: CN523

Sensor error

Replace clogged part.

Compressor 1

Strainer

Capillary tube

TK1

7
1	(SV3A)
	Solenoid
Strainer	valve
	(SV3B)
Balance pipe	Check
Packed valve	valve
	3

Check the clogging of SV3E valve. Error Oil tank

(Note 1)

(Note 1) Refer to item [H07] error.

No error

Check I/F P.C. board Replace SV3E valve.