Mitsubishi Electronics MXZ-24UV - E2 Heat defrosting control, High pressure protection

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11-3.Heat defrosting control

(1) Conditions to enter defrosting mode

1. When temperature of defrosting thermistor is -3;or less.

2.When specified non-defrosting time, is counted in the control p.c.board is satisfied. (Total time of compressor operating)

Going to defrosting mode at both condition of 1 and 2.

(2) Defrosting operation

1. Compressor stops for 50 seconds, Indoor fan is off, Defrosting lamp lights

2.4-way valve reverses flow, Compressor operates by the frequency in heat defrosting control. 3. After compressor stops for 35 seconds, 4-way valve reverses flow, then defrosting finishes.

(3) Conditions to finish defrosting mode

1. When the defrosting thermistor temperature is 8; or more.

2. When it has spent 10 minutes for defrosting. Defrosting finishes at condition of 1 or 2.

11-4.High pressure protection

(1) High pressure protection control on heat mode

Temperature of the main pipe temp. thermistor in the indoor unit controls the operation frequency.

When temperature of the main pipe temp. thermistor is approx. 49;, the operation frequency is set at the current level. When temperature of the main pipe temp. thermistor is approx. 52; the protection control decreases the frequency at the speed of 3Hz a minutes.

When temperature of the main pipe temp. thermistor is approx. 57; the protection decreases the frequency at the speed of 4Hz a minute and changes the outdoor fan to Low.

Note: Temperature of the pipe temp. thermistor is different depending on the indoor unit. Temperature of the pipe temp. thermistor is 45; or less, the protection control is Released.

(2) High pressure protection control by high pressure switch (H.P.S) High-pressure switch controls the operation frequency and outdoor fan motor. <Control status>

When high-pressure switch is ON.

(When discharge pipe pressure is 2.75 MPa or more.) <Control details>

(a)When cooling or drying

The protection control decreases the compressor frequency at the speed of 10Hz a minute.

(The compressor operates continuously in min. frequency according to a command to decrease more than the min. level.)

(b)When heating

The protection control decreases the compressor frequency at the speed of 10Hz a minute.

The protection control changes the outdoor fan to Low. <Release status>

When high-pressure switch is OFF. (When discharge pipe pressure is 2.35 MPa or more.) Or, the compressor stops.

11-5.Discharge temperature protection control

This protection controls the compressor ON/OFF and operation frequency according to temperature of the discharge temp. thermistor.

(1) Compressor ON/OFF

When temperature of the discharge temp. thermistor exceeds 116;, the control stops the compressor. When temperature of the discharge temp. thermistor is 80; or less, the controls starts the compressor.

(2) Compressor operation frequency

When temperature of the discharge temp. thermistor is expected to be higher than 116;, the control decreases 12Hz from the current frequency.

When temperature of the discharge temp. thermistor is expected to be higher than 111; and less than 116;, the control decreases 6Hz from the current frequency.

When temperature of the discharge temp. thermistor is expected to be higher than 104; and less than 111;, the control is set at the current frequency.

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Contents Contents MXZ-24UV E1 MXZ-24UV E2Technical Changes MXZ-24UV E1 MXZ-24UV E2Part Names and Functions Outdoor UnitIndoor / Outdoor Correspondence Table Outdoor UnitIndoor Units Combination 07+071930 7.2 470-2300 Specification MXZ-24UV E1 , MXZ-24UV E20dB = Test conditions Cooling DB35 WB24Heating DB Band Center FREQUENCIES, HzOutlines and Dimensions Unit mmWiring Diagram SG79A845H01Refrigerant System Diagram UnitmmCWB Capacity and the Input CurvesCDB Capacity and input correction by inverter output frequency Class unit in single operationAmbient temperature Or any button on remote controller33Hz Ambient temperature/ Ambient humidity% Heat operationCurrent 33HzOutdoor 45Hz 10 15 20 Inverter Multi System Control Microprocessor ControlSSR61 LEV control Cool DRY Heat CorrectionSuction superheat S.H LEV opening Min Max Rated Operational frequency rangeMin Max DRY CoolHeat defrosting control Discharge temperature protection controlHigh pressure protection Relation between main sensor and actuator Refrigerant recovery control on heatingOutdoor fan control Relation between main sensor and actuatorBefore troubleshooting, check the following TroubleshootingInstruction of troubleshooting Lead wiring Housing point Troubleshooting procedureTroubleshooting check table LEVOutdoor unit operates Trouble criterion of main parts Outdoor unit does not operate. LED display display OFF Outdoor unit does not operate. LED displayWhen heating operation does not work. Start When cooling operation does not work. StartCheck the resistance Power supply of outdoor unit wasTurned off, disconnect the connector Minutes or more normal Relay P. C. boardLED Infinity Return CN722 to formerTest Point Diagram and Voltage MXZ-24UV E1 , MXZ-24UV E2 Electronic control P.C.boardOutdoor FAN 230V AC Reversing Valve 230V AC Noise filter P.C.board MXZ-24UV E1MXZ-24UV E2 M P.C.board MXZ-24UV E1 MXZ-24UV E2 Relay P.C.board MXZ-24UV E1 MXZ-24UV E2Removing the compressor Photo Disassembly InstructionsOutdoor Unit Operating Procedure Photos Discharge pipe brazed part Suction pipe braxed partRemoving the 4-way valve Photo 1Remove the service panel.See PhotoRemoving the fan motor 1Remove the screws of the top panel , and remove it.SeeOperating Procedure Photos Removing the reactorParts List Outdoor Unit Functional Parts MXZ-24UV E1Outdoor Unit Structural Parts MXZ-24UV E1 6 7Accessory Parts MXZ-24UV E1 MXZ-24UV E2 MXZ-24UV MAC-855SG MXZ-24UV51H-855 Page Made in Japan

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.