Toshiba MMU-AP0181MH, MMU-AP0151MH Leakage check for SV3C valve, Clogging for SV3E valve

Check code name

Check code name

Cause of operation

[H07]

Oil level down

1. Valves of balance pipes closed.

detection protection

2. Miscabling or misinstallation of TK1 to TK4 sensors

3.

TK1 to TK4 sensor error

4.

Gas leak or oil leak of all outdoor units

5.

Refrigerant stagnation of compressor case

6.

SV3A, 3B, 3D, 3C, 3E valve error

7.

Clogging of oil return circuit from oil separator

8.

Clogging of oil-equation circuit system

Are TK1, TK2, TK3, and

NO

Correct miswiring and misinstallation.

TK4 sensors connected correctly?

TK1: CN514, TK2: CN515

)

Is there no sensor coming-off or misinstallation?

( TK3: CN516, TK4: CN523

a)

Leakage check for SV3A valve (For multiple outdoor unit system)

•

Turn off the power supply, take off connector of SV3A valve, and then start a test operation after power-ON.

•

Check the temperature change at secondary side of SV3A valve during operation . (• in the figure.)

→ If temperature is raised, it is a leakage of SV3A valve. Replace SV3A valve.

b)

Leakage check for SV3C valve

•

Turn off the power supply, take off connector of SV3C valve, and then start a test operation after power-ON.

•

After operation for several minutes, check temperature at secondary side of SV3C valve. (‚ in the figure.)

→ If temperature is high (equivalent to discharge temperature TD), it is a leakage of SV3C valve. Replace

SV3C valve.

(Even if there is leakage from SV3C valve does not occur, temperature of SV3C valve at secondary side

rises during operation. When the checked temperature is equivalent to TD temperature, it is a leakage of

SV3C valve. Replace SV3C valve.)

c) Clogging check for SV3B valve (For multiple outdoor unit system)

• While outdoor unit is operated, set up SW01/02/03 = [2] [1] [3] to 7-segment display [Hr] [ 2], and push SW04

for 2 seconds or more.

Check whether there is setup missing

Abnormal

Set up to cooling only operation mode.

Item code (DN) OF

of cooling only indoor unit.

Cooling only operation mode: 0001

Normal

NO

Are characteristics of TK1 to TK4 normal?

Characteristics-4

Sensor error Replace

YES

Check gas leak of outdoor unit.

Abnormal

Specify a position where

Check oil stain in the

gas leaked and repair it.

( machine room of outdoor unit. )

(Recharge, refill oil.)

Normal

NO

Is the flow selector unit normal?

Repair the flow selector unit.

YES

Check accumulation of

NO

( 1) Check leakage of

YES

solenoid valve. (SV3C)

Replace defective parts

refrigerant in compressor case.

Check clogging.

Refrigerant accumulation

(SV3E)

No leakage or clogging

Correct accumulation of

refrigerant in compressor case,

reset power supply and

( 2) Check clogging in oil

then start operation.

YES

recovery circuit of the oil separator.

Replace defective parts

(Capillary, Strainer)

Check clogging of SV3D valve.

Check oil level judgment

No clogging

of each compressor.

SW01/02/03=1/16/1

are

displayed on 7-

segment display.

Are all the oil levels appropriate?

NO

YES

Clogging

Eliminate cause of accumulation.

Check clogging of oil-equation circuit.

Replace defective parts

( 3)

• Set up SW02 = [9], and turn on SV3A, SV3B, SV3C valves. (7-segment display [Hr] [ 3–])

• While outdoor unit is operating, check temperature change at secondary side of SV3B valve. (ƒ in the figure.)

→ If temperature does not rise (equivalent to suction temperature), it is a clogging of SV3B valve.

Replace SV3B valve.

d) Clogging for SV3E valve

Reset the power supply.