MITSUBISHI ELECTRIC EHST20D Air to Water Heat Pump Systems User Manual

EHST20D Air-to-Water Heat Pump Systems

Revision

•  Added EHST20D-VM2EC.UK, EHST20D-YM9C.UK, ERST20C-VM2C.UK, ERST20C-MEC.UK, ERST20D-VM2C.UK and ERST20D-MEC.UK in REVISED EDITION-A.
•  Some descriptions have been modified.
•  Please void OCH570.

Note

•  This manual describes only the service data of the cylinder unit.
•  RoHS-compliant products have mark on the spec nameplate.

REFERENCE MANUAL

OUTDOOR UNIT’S SERVICE MANUAL

Please read the following safety precautions carefully.

WARNING
Precautions must be observed to prevent injuries or death.

CAUTION
Precautions must be observed to prevent damage to the unit.

This installation manual along with the user manual should be left with the product after installation for future reference. Mitsubishi Electric is not responsible for the failure of locally-supplied parts.

• Be sure to perform periodical maintenance.
• Be sure to follow your local regulations.
• Be sure to follow the instructions provided in this manual.

WARNING

Mechanical

• The cylinder unit and outdoor unit must not be installed, disassembled, relocated, altered or repaired by the user. Ask an authorized installer or technician. If the unit is installed improperly or modified after installation by the user water leakage, electric shock or fire may result.
• The outdoor unit should be securely fixed to a hard-level surface capable of bearing its weight.
• The cylinder unit should be positioned on a hard-level surface capable of supporting its filled weight to prevent excessive sound or vibration.
• Do not position furniture or electrical appliances below the outdoor unit or cylinder unit.
• The discharge pipework from the emergency devices of the cylinder unit should be installed according to local law.
• Only use accessories and replacement parts authorized by Mitsubishi Electric ask a qualified technician to fit the parts

Electrical

• All electrical work should be performed by a qualified technician according to local regulations and the instructions given in this manual.
• The units must be powered by a dedicated power supply and the correct voltage and circuit breakers must be used.
• Wiring should be in accordance with national wiring regulations. Connections must be made securely and without tension on the terminals.
• Earth unit correctly.

General

• Keep children and pets away from both the cylinder unit and the outdoor unit.
• Do not use the hot water produced by the heat pump directly for drinking or cooking. This could cause illness to the user.
• Do not stand on the units.
• Do not touch switches with wet hands.
• Annual maintenance checks on both the cylinder unit and the outdoor unit should be conducted by a qualified person.
• Do not place containers with liquids on top of the cylinder unit. If they leak or spill onto the cylinder unit damage to the unit and/or fire could occur.
• Do not place any heavy items on top of the cylinder unit.
• When installing, relocating, or servicing the cylinder unit, use only the specified refrigerant (R410A) to charge the refrigerant lines. Do not mix it with any other
• refrigerant and do not allow air to remain in the lines. If air is mixed with the refrigerant, then it can be the cause of abnormally high pressure in the refrigerant
• line, and may result in an explosion and other hazards.
• The use of any refrigerant other than that specified for the system will cause mechanical failure or system malfunction or unit breakdown. In the worst case, this
• could lead to a serious impediment to securing product safety.
• In heating mode, to avoid the heat emitters being damaged by excessively hot water, set the target flow temperature to a minimum of 2°C below the maximum
• allowable temperature of all the heat emitters. For Zone2, set the target flow temperature to a minimum of 5°C below the maximum allowable flow temperature
  of all the heat emitters in the Zone2 circuit.

CAUTION

• Use clean water that meets local quality standards on the primary circuit.
• The outdoor unit should be installed in an area with sufficient airflow according to the diagrams in the outdoor unit installation manual.
• The cylinder unit should be located inside to minimize heat loss.
• Water pipe-runs on the primary circuit between the outdoor and indoor unit should be kept to a minimum to reduce heat loss.
• Ensure condensate from the outdoor unit is piped away from the base to avoid puddles of water.
• Remove as much air as possible from the primary and DHW circuits.
• Refrigerant leakage may cause suffocation. Provide ventilation in accordance with EN378-1.
• Be sure to wrap insulation around the piping. Direct contact with the bare piping may result in burns or frostbite.
• Never put batteries in your mouth for any reason to avoid accidental ingestion.
• Battery ingestion may cause choking and/or poisoning.
• Install the unit on a rigid structure to prevent excessive sound or vibration during operation.
• Do not transport the cylinder unit with water inside the DHW tank. This could cause damage to the unit.
• If power to the cylinder unit is to be turned off (or the system is switched off) for a long time, the water should be drained.
• If unused for a long period, before the operation is resumed, the DHW tank should be flushed through with potable water.
• Preventative measures should be taken against the water hammer, such as installing a Water Hammer Arrestor on the primary water circuit, as directed by the manufacturer
• As for the handling of refrigerant, refer to the outdoor unit installation manual.

WARNING (SPLIT MODELS ONLY)

• Do not discharge refrigerant into the atmosphere if refrigerant leaks during the installation, ventilate the room.
• Use appropriate tools for the high-pressure refrigerant.
• When pumping down refrigerant, stop the compressor before disconnecting the refrigerant pipes.
• During installation securely fasten the refrigerant pipes before starting the compressor.
• Check that refrigerant gas does not leak after the completion of installation.
• Use R41 DA refrigerant only. Do not allow air to enter the lines. Failure to observe these instructions will cause mechanical failure, system failure or, in the worst case, a serious breach of product safety.

CAUTION (SPLIT MODELS ONLY)

< Using R41 DA refrigerant heat pumps>
Use C122D copper phosphorus, for copper and copper alloy seamless pipes, to connect the refrigerant pipes. Make sure the insides of the pipes are clean and do not contain any harmful contaminants such as sulfuric compounds, oxidants, debris, or dust. Use pipes with the specified thickness. (Refer to section 4.4 in the installation manual.) Note the following if reusing existing pipes that carried R22 refrigerant.

• Replace the existing flare nuts and flare the flared sections again.
•  Do not use thin pipes. (Refer to section 4.4 in the installation manual.)
• Store the pipes to be used during installation indoors and keep both ends of the pipes sealed until just before brazing. (Leave elbow joints, etc. in their packaging.)
• If dust, debris, or moisture enters the refrigerant lines, oil deterioration or compressor breakdown may result.
• Use ester oil, ether oil, alkyl benzene oil (small amount) as the refrigeration oil applied to the flared sections. If mineral oil is mixed in the refrigeration oil, oil deterioration may result.
• Do not use refrigerant other than R41 DA refrigerant. If another refrigerant is used, the chlorine will cause the oil to deteriorate.
• Use the following tools specifically designed for use with R41 DA refrigerant. The following tools are necessary to use R41 DA refrigerant. Contact your nearest dealer for any questions

Tools (for R41 DA)

• Gauge manifold Flare tool
• Charge hose Size adjustment gauge
• Gas leak detector Vacuum pump adapter
• Torque wrench Electronic refrigerant charging scale

Be sure to use the correct tools. If dust, debris, or moisture enters the refrigerant lines, refrigeration oil deterioration may result Do not use a charging cylinder, a cylindrical measuring container, when charging R41 DA refrigerant gas. If the refrigerant gas is transferred to a charging cylinder, the composition of the refrigerant will change and system efficiency will be reduced

Cautions for service

1.  Perform service after recovering the refrigerant left in unit completely.
2. Do not release refrigerant in the air.
3.  After completing the service, charge the cycle with a specified amount of refrigerant.
4.  When performing service, install a filter drier simultaneously.
5. Be sure to use a filter drier for the new refrigerant.

Additional refrigerant charge
When charging directly from a refrigerant cylinder

• Check that cylinder for R41 0A on the market is siphon type.
• Charging should be performed with the refrigerant cylinder of the siphon standing vertically.
• (Refrigerant is charged from the liquid phase.)

Service tools
Use the service tools below as exclusive tools for R410A refrigerant.

Specifications

Parts Names And Function

Supplied with UK model ONLY. Please refer to PAC-WK01 UK-E Installation Manual for more information on accessories.
< Note> For installation of the E*ST20″‘-•M•Ec model, make sure to install a primary-side expansion vessel in the field. (See figure 4.3.4 in Installation Manual.)

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