G Check of outdoor thermistors

Disconnect the connector of thermistor in the outdoor P.C. board (see below table), and measure the resistance of thermistor.

Is the resistance of thermistor normal?

No

(Refer to 10-6.1.)

 

Yes

 

 

 

 

 

 

Replace the thermistor except RT64. When RT64 is abnormal, replace the inverter P.C. board.

Reconnect the connector of thermistor.

Turn ON the power supply and press EMERGENCY OPERATION switch.

Does the unit operate for 10 minutes or more

 

 

 

 

 

 

 

Replace the inverter P.C. board.

 

without showing thermistor abnormality?

 

No

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OK.

 

 

 

 

 

 

 

 

 

 

(Cause is poor contact.)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thermistor

Symbol

 

 

Connector, Pin No.

 

Board

Defrost (MUZ)

RT61

Between CN641 pin1 and pin2

 

 

Discharge temperature

RT62

Between CN641 pin3 and pin4

Inverter P.C. board

Fin temperature

RT64

Between CN642 pin1 and pin2

Ambient temperature

RT65

Between CN643 pin1 and pin2

 

 

Outdoor heat exchanger temperature

RT68

Between CN644 pin1 and pin3

 

 

H Check of R.V. coil (MUZ)

First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 10-4.

In case CN721 is disconnected or R.V. coil is open, voltage is generated between the terminal pins of the connector although no signal is being transmitted to R.V. coil.

Check if CN721 is connected.

Unit operates COOL mode even if it is set to HEAT mode.

Disconnect connector (CN61) between the compressor and the intelligent power module.

Turn ON the power supply and press EMERGENCY OPERATION switch twice (HEAT mode).

Is there 208/230 VAC between CN721

 

 

 

and on the inverter P.C. board 3

 

 

Replace the inverter

minutes after the power supply is turned

No

 

P.C. board.

ON?

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

Replace the 4-way valve.

Unit operates HEAT mode even if it is set to COOL mode.

Disconnect connector (CN61) between the compressor and the intelligent power module.

Turn ON the power supply and press EMERGENCY OPERATION switch once (COOL mode).

Is there 208/230 VAC between CN721

 

 

 

and on the inverter P.C. board 3

 

 

Replace the inverter

minutes after the power supply is turned

Yes

 

P.C. board.

ON?

 

 

 

 

 

 

 

No

 

 

 

 

 

 

 

 

 

 

 

 

Replace the 4-way valve.

31

Page 30 Page 32
Page 31
Image 31
Mitsubishi Electronics MUZ-GE09NA, MUY-GE12NA, MUY-GE15NA Check of outdoor thermistors, Check of R.V. coil MUZ, On?
Page 30 Page 32

MUZ-GE09NA, MUZ-GE15NA, MUY-GE15NA, MUZ-GE18NA, MUZ-GE12NA specifications

Mitsubishi Electronics offers a range of advanced air conditioning systems, including the MUY-GE12NA, MUY-GE18NA, MUY-GE09NA, MUZ-GE12NA, and MUZ-GE18NA models. These units are designed for optimal energy efficiency and superior comfort, making them ideal for residential and commercial applications.

One of the standout features of these models is their inverter technology. By adjusting the compressor speed according to the cooling or heating demand, inverter systems provide precise temperature control while significantly reducing energy consumption compared to traditional units. This not only translates to lower utility bills but also less environmental impact.

The MUY-GE series units come with a user-friendly remote control that allows for easy adjustments of temperature settings, fan speeds, and operational modes. Smart operation modes include cooling, heating, and dehumidification, thereby catering to various climate needs. The units also include a programmable timer, enabling users to set the air conditioner to operate at specific times, enhancing convenience and efficiency.

Another impressive characteristic is the advanced air filtration system. Mitsubishi integrates a multi-stage filtration mechanism that includes a washable pre-filter, a pleated filter, and a high-performance deodorizing filter. This ensures cleaner indoor air by effectively reducing allergens, dust, and odors, contributing to a healthier living space.

The sleek and modern design of these units also allows for easy installation and compatibility with various interior settings. The MUY-GE09NA, MUY-GE12NA, and MUY-GE18NA indoor units are designed to be compact and unobtrusive, while the outdoor units (MUZ series) are engineered for durability and quiet operation.

Noise levels are another critical aspect where Mitsubishi excels. These air conditioning systems operate quietly, making them suitable for bedrooms, offices, and other noise-sensitive environments. Their Whisper-Quiet technology ensures that sound levels during operation remain low, promoting a peaceful atmosphere.

Mitsubishi Electronics ensures customer satisfaction with robust support and warranty options, emphasizing quality and reliability. In summary, the MUY-GE12NA, MUY-GE18NA, MUY-GE09NA, MUZ-GE12NA, and MUZ-GE18NA models stand out for their energy-efficient inverter technology, user-friendly controls, advanced air filtration, sleek design, and quiet operation, making them a smart choice for modern cooling and heating needs.
Top Page Image Contents