Symptom

 

Outdoor unit operates. (The compressor operates at reduced frequency.)

 

 

 

 

Display

Detecting method

Detecting method

Check points

 

 

 

 

d8

Frequency drop by current

When the outdoor unit input current exceeds 22.5 A, the compressor

 

(d8)

protection

operates at reduced frequency.

 

d9

Frequency drop by overload

When the compressor load exceeds the specified value, the compres-

These symptoms do not mean any

(d9)

protection

sor operates at reduced frequency.

abnormality of the product, but check the

 

 

 

 

Frequency drop by high pres-

When indoor pipe temperature exceeds 55˚C during heating, the com-

following points.

d7

sure protection

pressor operates at reduced frequency.

• Air filter clogging.

(d7)

 

 

• Amount of gas.

Frequency drop by defrosting

When the indoor pipe temperature falls to 6˚C or below during cooling,

• Short cycle of indoor/outdoor air flow.

 

in cooling

the compressor operates at reduced frequency.

 

 

 

 

 

d6

Frequency drop by discharge

When the discharge temperature exceeds 110˚C, the compressor oper-

 

(d6)

temperature protection

ates at reduced frequency.

 

d3

Frequency drop by high pres-

When the high pressure exceeds 2.75MPa (28 kgf/cm2-G), the com-

• Amount of gas.

(d3)

sure switch protection

pressor operates at reduced frequency. In addition, the fan speed

• Outdoor unit air passage.

 

changes.

 

 

 

 

 

d1

 

When the state with low discharge temperature of which 50˚C in COOL

Check the amount of gas.

Low discharge temperature

• Replace the outdoor controller board.

(d1)

protection

and 48.4 or less in HEAT for 20 minutes, the compressor operates con-

• Check the contact of LEV board connec-

 

tinuously.

tors.

 

 

 

 

 

 

 

 

 

 

 

Symptom

 

Outdoor unit operates.

 

 

 

 

 

Display

Detecting method

Detecting method

Check points

 

 

 

 

e7

Defrost thermistor abnormality

When a short or open circuit occurs in the defrost thermistor during

• Defrost thermistor characteristic.

(E7)

heating

• Contact of P. C. board connectors.

 

* In this case, the compressor continues to operate.

 

 

 

 

 

 

h4

Power factor detection abnor-

When the compressor power factor cannot be detected

• Compressor wiring.

(h4)

mality

* In this case, the compressor keeps running.

 

 

 

 

 

 

 

 

26

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Mitsubishi Electronics MXZ-24UV - E2 service manual Outdoor unit operates

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.