When cooling, heat exchanger of non-operating indoor unit frosts.

When heating, non-operating indoor unit get warm.

(LED display: 00, p1)

D Check of LEV

Start

Turn on power supply to the outdoor unit after checking LEV coil is mounted to the LEV body securely.

Is "click - click" sound heard?

Or, do you feel vibration of the LEV coil with a hand? No

Disconnect the connector

(CN791: unit A, CN792: unit B, CN793: unit C), and measure the resistance of LEV coil to check the integrity.

No

Replace the LEV coil.

Yes

Nomal

Yes Replace the electronic control P. C. board

When heating, room does not get warm.

When cooling, room does not get cool. (LED display: 00, a8)

E Check of inverter/ compressor

Start

Disconnect the lead wire to the compressor at terminals, and turn on power supply to the indoor and outdoor unit. Three minutes later, EMERGENCY OPERATION starts.

 

 

 

W1 • After the outdoor fan starts running, wait for 1 minutes or more before

 

 

 

Measure the voltage between

 

measuring the voltage.

 

 

 

 

 

 

 

 

each leading to the compressor.

• The output voltage values in the above table have the tolerance of i20%.

U (BLK) - V (WHT)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V (WHT) - W (RED)

 

No

LED indicator the inverter

No

 

1. Turn off power supply of the indoor

W (RED) - U (BLK)

 

 

 

 

stops due to over current?

 

 

 

 

and outdoor unit, and disconnect

Output voltage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the connector CN 551 in the relay

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COOL: 100V(58Hz) HEAT: 100V(58Hz)

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

P. C. board

Is voltage output? W1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Turn on power supply to the outdoor

 

 

 

 

 

Replace the electronic

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

unit, and after 1 minutes or more

 

 

 

 

 

 

 

 

Is output balanced?

No

 

 

 

 

control P. C. board

 

 

 

 

 

 

passed, check the resistance

 

 

 

 

with the I.P.M P. C. board.

 

 

 

 

 

 

between the connector

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CN551 pin 1 and pin 2.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Turn off power supply of indoor and outdoor unit,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

and measure the compressor winding resistance

 

No

 

 

 

 

0"

 

 

Check the resistance

between the compressor terminals.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

between each terminal

Is there resistance of 0.27" to 0.34" between

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the each terminals?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Infinite

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replace the

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

compressor.

 

 

 

 

 

After 1 minutes has passed since the

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Return the lead wire of compressor to former, and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

power supply of outdoor unit was

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

turned off, disconnect the connector

turn on power supply to indoor and outdoor unit.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CN 553 in the noise filter P. C. board.

Three minutes later EMERGENCY OPERATION starts.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Check the resistance

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Clarify the causes by counting time until the inverter stops.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HPS (63H2).

0 to 10 seconds: compressor rare short

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10 to 60 seconds: compressor lock

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Infinite

60 seconds to 5minutes: refrigerant circuit defective

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replace the

 

 

 

 

 

Replace the

 

5 minutes or more: normal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

relay P. C. board.

 

 

 

 

HPS (63H2).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30

Page 30
Image 30
Mitsubishi Electronics MXZ-24UV - E2 service manual Check the resistance, Power supply of outdoor unit was

MXZ-24UV - E2, MXZ-24UV specifications

Mitsubishi Electronics has established itself as a leader in the HVAC (heating, ventilation, and air conditioning) industry with its MXZ-24UV and MXZ-24UV - E2 models. These multi-zone heat pump systems are designed to provide exceptional efficiency, comfort, and versatility for residential and commercial applications.

One of the main features of the MXZ-24UV is its ability to effectively cool and heat multiple rooms simultaneously. This system allows for the connection of up to four indoor units, enabling users to customize the climate in different spaces while maintaining energy efficiency. This zoning capability ensures you can maintain the perfect temperature in each room according to the occupants' preferences.

The MXZ-24UV incorporates advanced inverter technology, which allows the compressor to adjust its speed based on the required heating or cooling demand. This results in reduced energy consumption compared to conventional systems, providing significant savings on energy bills while also promoting a more consistent indoor temperature. The inverter-driven compressor operates quietly and efficiently, making it a suitable choice for residential areas.

Additionally, these models are equipped with a range of smart technologies. The built-in Wi-Fi capability allows homeowners to control the system remotely using a smartphone or tablet. This feature adds convenience and flexibility, enabling users to adjust settings from anywhere, ensuring their space is at the desired temperature upon arrival.

Durability is another essential characteristic of the MXZ-24UV and MXZ-24UV - E2 models. Mitsubishi has designed these units to withstand various weather conditions, enhancing longevity and reliability. The units feature a robust construction that minimizes wear and tear while ensuring dependable performance year after year.

Moreover, the system has a variety of indoor unit options, including wall-mounted, ceiling-mounted, and floor-mounted designs. This versatility makes it easy to integrate into different architectural styles and preferences, ensuring both aesthetics and functionality.

In summary, the Mitsubishi Electronics MXZ-24UV and MXZ-24UV - E2 models are designed for those seeking energy efficiency, flexibility, and durability in a multi-zone heating and cooling system. With advanced inverter technology, smart home capabilities, and a range of indoor unit styles, these systems offer exceptional comfort while minimizing energy costs, making them a top choice in the HVAC market.