HYDROBOX July 2011 No. OCH503 TENTATIVE SERVICE MANUAL R410A [Model name] [Service Ref.] Note: EHSC-VM6A.UK • This manual describes only EHSC-VM6A service data of Hydrobox. • RoHS compliant products have mark on the spec name EHSC-YM9A.UK EHSC-YM9A plate. EHPX-VM2A.UK...
Do not position furniture or electrical appliances below the outdoor unit or hydrobox. The discharge pipework from the emergency/safety devices of the hydrobox should be installed according to local law. Only use accessories and replacement parts authorised by Mitsubishi Electric and employ a qualifi ed technician to fi t the parts. Electrical All electrical work should be performed by a qualifi...
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WARNING (SPLIT MODELS ONLY) Do not discharge refrigerant into the atmosphere if refrigerant leaks during installation, ventilate the room. Use appropriate tools for 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.
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CAUTIONS RELATED TO NEW REFRIGERANT Cautions for units utilizing refrigerant R410A Use a vacuum pump with a reverse flow check Use new refrigerant pipes. valve. If using the existing R22, be careful of the followings. Vacuum pump oil may flow back into refrigerant cycle and ·...
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[1] 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 service, charge the cycle with specified amount of refrigerant. (4) When performing service, install a filter drier simultaneously. Be sure to use a filter drier for new refrigerant.
SPECIFICATIONS Model name EHSC-VM6A EHSC-YM9A EHPX-VM2A Overall unit dimensions 800 × 530 × 360 mm (Height × Width × Depth) Weight (empty) 54 kg 54 kg 39 kg Weight (full) 60 kg 60 kg 44 kg Plate heat exchanger Unvented expansion vessel...
PART NAMES AND FUNCTIONS (Split model system) Number Component Control and electrical box Main controller Manometer Expansion vessel Expansion vessel charge valve Automatic air vent Booster heater Drain cock Water circulation pump Pressure relief valve Flow switch Plate heat exchanger Strainer valve Inlet from space heating/Indirect DHW cylinder (primary return)
Page 9 (Packaged model system) Number Component Control and electrical box Main controller Manometer Expansion vessel Expansion vessel charge valve Automatic air vent Booster heater Drain cock Water circulation pump Pressure relief valve Flow switch Strainer valve Inlet from space heating/Indirect DHW cylinder (primary return) Inlet from heat pump Outlet to heat pump...
OUTLINES AND DIMENSIONS 5-1. Technical Drawings (Unit: mm) (Split model system) (233) Letter Pipe description Connection size/type Space heating/Indirect DHW cylinder (pri- 28 mm/Compression mary) return connection Space heating/Indirect DHW cylinder (pri- 28 mm/Compression mary) fl ow connection Refrigerant (Liquid) 9.52 mm/Flare Refrigerant (Gas)
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5-2. Service access diagrams Service access Parameter Dimension (mm) Suffi cient space MUST be left for the provision of discharge pipework as detailed in National and Local building regulations. The hydrobox must be located indoors and in a frost-free environment, for example in a utility room.
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6-4. Dip switch setting Located on the FTC3 printed circuit board are 4 sets of small white switches known as Dip switches. The Dip switch number is printed on the circuit board next to the relevant switches. The word ON is printed on the circuit board and on the Dip switch block itself.
Wiring Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW (EHPX-VM2A) 16 A *1 2.5 mm² 6 kW (EHSC-VM6A) 32 A *1 6.0 mm² Hydrobox - Outdoor unit 3 × 1.5 (polar) Hydrobox - Outdoor unit earth 1 × Min. 1.5...
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<3 phase> Hydrobox Outdoor unit To control board Power Wiring supply Earth circuit leakage breaker 400V breaker Isolating 50Hz switch ECB1 ELB for Wiring booster Power circuit heater supply breaker (Primary circuit) 400V Isolating switch 50Hz * Installer MUST affi x label A that is included with the manuals near each wiring diagram for hydrobox and outdoor units. ...
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Capacity (Indoor unit Ref.) Breaker Wiring Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW (EHPX-VM2A) 16 A *1 2.5 mm² 6 kW (EHSC-VM6A) 32 A *1 6.0 mm² Hydrobox power supply ~/N 230 V 50 Hz Hydrobox input capacity 16 A...
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<3 phase> Hydrobox Power Wiring supply Earth circuit breaker leakage 230V breaker Isolating 50Hz switch Outdoor unit To control board Power Wiring supply circuit Earth breaker leakage 400V breaker Isolating 50Hz switch ECB1 ELB for Wiring booster Power circuit heater supply breaker (Primary circuit)
WATER SYSTEM DIAGRAM EHSC-VM6A EHSC-YM9A EHPX-VM2A Filling the System (Primary Circuit) 1. Check all connections including factory fi tted ones are tight. 2. Insulate pipe work between hydrobox and outdoor unit. 3. Thoroughly clean and fl ush, system of all debris. (see section 4.2 for detailed instructions.) 4.
CONTROLS 9-1. Main Controller Letter Name Function Screen Screen in which all information is displayed Menu Access to system settings for initial set up and modifi cations. Back Return to previous menu. Confi rm Used to select or save. (Enter key) Power/Holiday If system is switched off pressing once will turn sys- tem on.
Page 22 Unrestricted access Initial Installer only Main screen Shaded items relate Information to DHW functions. Option These are only avail- Forced DHW ON/OFF able if the system ON/OFF/Timer includes a DHW tank. Heating ON/OFF/Timer Holiday Active/Non active Set time Main menu Normal...
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9-2. Service Menu The service menu provides functions for use by installer or service engineer. It is NOT intended the home owner alters settings within this menu. It is for this reason password protection is required to prevent unauthorised access to the service settings.
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Auxiliary Setting This function is used to set the parameters for any auxiliary parts used in the sys- tem. From the service menu use F1 and F2 buttons to highlight Auxiliary setting then press CONFIRM. Auxiliary setting menu screen From the Auxiliary setting menu highlight Economy Settings for pump.
Page 25 During the fi lling of the system the pump and 3-way valve can be manually over- ridden using manual operation mode. When manual operation is selected a small timer icon appears in the screen. The function selected will only remain in manual operation for a maximum of 2 hours. This is to prevent accidental permanent override of the FTC3.
Page 26 The default heat source setting is heat pump and all electric heaters present in the system to be operational. This is referred to as Standard operation on the menu. From the service menu use F1 and F2 buttons to scroll through list until is highlighted.
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Operation Setting Menu To access the Operation setting menu use F1 and F2 buttons to scroll through the service menu until Operation setting is highlighted. Press CONFIRM. Operation setting menu is displayed. Operation setting menu screen For periods of very low outside temperature this mode can be used. Simultane- ous operation allows both DHW and space heating to be provided simultaneously by using the heat pump to provide space heating whilst only the immersion heater (if fi...
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Indoor unit switch setting display (Request code: 162 to 165) 0: OFF 1: ON 0: OFF 1: ON SW1, SW2, SW3, SW4 SW1, SW2, SW3, SW4 Display Display 00 00 00 40 00 01 00 41 00 02 00 42 00 03 00 43 00 04...
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Indoor unit switch setting display (Request code: 162 to 165) 0: OFF 1: ON 0: OFF 1: ON SW1, SW2, SW3, SW4 SW1, SW2, SW3, SW4 Display Display 00 80 00 C0 00 81 00 C1 00 82 00 C2 00 83 00 C3 00 84...
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Output signal display (Request code: 175) Please refer to Table 2 on relevant wiring diagram whilst using the following. 0: OFF 1: ON 0: OFF 1: ON Display Display xx 00 xx 40 xx 01 xx 41 xx 02 xx 42 xx 03 xx 43 xx 04...
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Indoor unit switch setting display (Request code: 175) Please refer to Table 2 on relevant wiring diagram whilst using the following. 0: OFF 1: ON 0: OFF 1: ON Display Display xx 80 xx C0 xx 81 xx C1 xx 82 xx C2 xx 83 xx C3...
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Input signal display (Request code: 176) Output signal display (Request code: 175) Please refer to Table 1 on relevant wiring diagram whilst using the following. Please refer to Table 2 on relevant wiring diagram whilst using the following. 0: OFF (open) 1: ON (short) 0: OFF 1: ON...
Page 33 This function shows the current readings of thermistors located on the water and refrigerant circuit Thermistor Description Room temperature Refrigerant return temperature THW1 Water flow temperature THW2 Water return temperature TH5A — TH5B Tank temperature TH5C — Ambient (outdoor) temperature ...
Page 34 Password protection is available to prevent unauthorised access to the service menu by untrained persons. From the service menu use F1 and F2 buttons to scroll through list until is highlighted. Press CONFIRM. When password input screen is displayed use buttons F1 and F2 to move left and right between the four digits, F3 to lower the selected digit by 1, and F4 to increase the selected digit by 1.
Page 35 In Emergency operation mode the outdoor heat pump unit will not operate. Heat- ing for DHW and space heating is provided by the booster heater and the tank immersion heater (if installed). Space heating flow temp is restricted 40°C if an immersion heater is not present on the DHW tank then the booster heater will also indirectly heat the DHW.
TROUBLESHOOTING 10-1. Troubleshooting Present and past Error codes are logged and displayed on the main controller or control board of the outdoor unit. Please refer to the table below and subsequent explanations to diagnose and remedy typical problems that may occur in the fi eld. Unit Condition Error Code Action...
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10-4. Self diagnosis and action Check if Dip SW is set correctly. (Refer to Chapter 6-10.) The components associated with the DHW tank are fi eld-supplied. Error code Title and display conditions Possible Cause Diagnosis and action Booster heater overheat detection Insuffi...
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Error code Title and display conditions Possible Cause Diagnosis and action Tank water temperature overheat protection 3-way valve actuator fault Electrically test to determine fault. Error code display when THW5B detects a Immersion heater relay (IHC) operating fault Check immersion heater relay (IHC) temp.
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Error code Title and display conditions Possible Cause Diagnosis and action 3-way valve failure (Valve direction 3-way valve actuator fault Electrically test to determine fault. defaults to DHW circuit) THW1 or THW5B fault Check resistance of thermistor against table Error code displayed when the THW1 temp.
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Error code Title and display conditions Possible Cause Diagnosis and action E0/E4 Main controller communication failure Contact failure with transmission cable Check connection cable for damage or loose (Reception error) connections at the FTC3 and main controller Error code E0 is displayed if main controller terminals.
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Error code Title and display conditions Possible Cause Diagnosis and action Indoor/outdoor communication failure Fault with FTC3 transmission/receiving (Transmission error) circuit board Turn the power to the indoor unit OFF and Error code E7 is displayed if despite the Electrical noise causes interference with then ON.
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10-5. Troubleshooting by inferior phenomena Fault symptom Possible cause Explanation - Solution Main controller display 1. There is no power supply to main controller. Check LED2 on FTC3. does not work. (i) When LED2 is lit. Check the main controller wiring for damage or contact failure. (ii) When LED2 is blinking.
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Please contact your Mitsubishi Electric dealer. 7. Immersion heater cut out has triggered. Check immersion heater thermostat and press reset button, located on immersion heater boss, if safe.
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24 Heating emitter is hot in The 3-way valve may have foreign objects in it, or hot Manually override the 3-way valve several times to check water may fl ow to the heating side due to malfunctions. whether the problem will be solved. (Refer to the service the DHW mode.
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Part Name Check Points Booster heater Measure the resistance between the terminals with a tester. Thermostat (90 °C) and thermal cut out (121 °C) Terminal Normal Abnormal 121 °C 90 °C 9-10 110(±35)mΩ Open or Short Manual reset Thermal cut-out water thermostat 2kW heater (230V, 1 phase)
Page 47 • Room temperature thermistor (TH1) • Liquid refrigerant temperature thermistor (TH2) • Flow water temperature thermistor (THW1) • Return water temperature thermistor (THW2) • DHW tank temperature thermistor (THW5B) Thermistor R0 = 15kΩ ± 3% B constant = 3480 ± 2% Rt = 15exp {3480 ( 273+t –...
● Do not expose the electric parts to water. ● When replacing or servicing water circuit parts, drain system first. EHSC-VM6A, EHSC-YM9A, EHPX-VM2A Check individual illustrations and positions of the parts by referring to the parts catalog included in this manual.
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PHOTOS DISASSEMBLY PROCEDURE 3. How to remove the electrical parts Photo 3-1 Control box cover fixing screws (Steps (1) through (3) are applied to all the following parts.) (1) Remove the front panel. (Refer to Procedure 1). (2) Remove the 4 screws holding the control box cover. (Photo 3-1) (3) Slightly lift and pull out the control box cover.
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PHOTOS DISASSEMBLY PROCEDURE 4. How to swing the control box to the front Photo 4-1 (1) Remove the front panel. (Refer to Procedure 1.) Earth cable Side panel (2) Remove the 2 screws from the 2 control box brackets (R). (3) Remove the cable straps.
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DISASSEMBLY PROCEDURE PHOTOS Photo 5-1 5. How to remove water pump/ pump valve Water pump connector (CNP1) Earth cable Close the 2 pump valves (OFF) before removing the water pump, and open the valves (ON) after reinstalling the water pump.
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DISASSEMBLY PROCEDURE PHOTOS 6. How to remove the flow switch Photo 6-1 (1) Remove the front panel. (Refer to Procedure 1.) (2) Remove the control box cover. (Refer to Procedure 3.) (3) Disconnect the CN2F connector on the controller board. (Photo 6-1) (4) Release the flow switch lead wire from the 3 cable clamps, the cable strap, the fastener and the 2 coated...
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BHC1-V No.1 No.2 BHC1 No.3 No.4 BHC2 Coated clamp Refer to 6.WIRING DIAGRAM w The photos shown are of the EHSC-VM6A model. Photo 7-2 Flare nut (5) Close (OFF) the pump valve (upper). (6) Remove the two 1" nuts. (Photo 7-2) w When reinstalling the 1"...
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DISASSEMBLY PROCEDURE PHOTOS Photo 7-4 7. How to remove the booster heater (continued) Flare joint (10) Remove the flare joint from the booster heater. (Photo 7-4) w When reinstalling the flare joint, use a new 3/8" gasket. Gasket (11) Remove the drain cock (primary circuit) from the booster (3/8") heater.
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DISASSEMBLY PROCEDURE PHOTOS Photo 8-1 8. How to remove the plate heat exchanger (1) Pump down the refrigerant circuit and close the stop Water pump connector (CNP1) Earth cable valve on the indoor unit. (Refer to "12. Supplementary information".) Control box (2) Remove the front panel.
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DISASSEMBLY PROCEDURE PHOTOS Photo 8-4 8. How to remove the plate heat exchanger (continued) (12) Remove the pump support under by removing the 4 screws. (Photo 8-4) Screw Note: To avoid dropping of the pump support under, Screw hold it by hand when removing the last screw. (13) Remove the 1"...
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DISASSEMBLY PROCEDURE PHOTOS 9. How to remove the strainer Photo 9-1 Gasket (1") Nut (1") (1) Remove the front panel. (Refer to Procedure 1.) Strainer valves Nut (1") (2) Cut the band. (3) Close the strainer valve (OFF). Gasket (1") w When either of the pump valve handles is stiff, remove the handle and turn the vertical stem 90 degrees clockwise mainly by using a spanner.
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DISASSEMBLY PROCEDURE PHOTOS 10. How to remove the manometer / pressure relief valve / air Photo 10-5 vent (automatic) (Continued) Expansion vessel Air vent (4) Remove the air vent with a flare joint using two spanners: one to hold the flare joint and the other to turn the flare nut.
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DISASSEMBLY PROCEDURE PHOTOS 12. How to remove the drain cock (primary circuit) Photo 12-1 Booster heater (1) Remove the front panel. (Refer to Procedure 1.) (2) Swing the control box to the front. (Refer to Procedure 4.) (3) Remove the drain cock (primary circuit). Drain cock Flexible hose Nut (1")
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DISASSEMBLY PROCEDURE PHOTOS Photo 14-1 14. How to remove the thermistor Control box (TH2) / thermistor Earth leakage breakers (ECB1) (THW1, THW2) (1) Remove the front panel. (Refer to Procedure 1.) (2) Remove the control box cover.
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Notes on replacing the parts Replacement of the parts listed below requires the following procedure. After the parts are removed, eliminate loctite on threads by applying loctite remover, apply new loctite, and then install and tighten the parts to the specifi ed tightening torques below.
SUPPLEMENTARY INFORMATION Refrigerant recovery (pump down) for split systems only For split system the following procedures should be followed to recover system refrigerant: Note) Pump down operation can not be activated by switching the pump down switch (SWP) or test run switch on the outdoor unit PCB. Ensure both the outdoor unit and the indoor unit are in emergency mode before carrying out the following.
SERVICE AND MAINTENANCE The main controller settings changed from the default settings are reset by replacing the controller board. To facilitate reselecting settings on the main controller, it is recommended to write down the changes in the sheet below before replacement. Engineers Forms Should settings be changed from default, please enter new setting in ‘Field Setting’...
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Annual Maintenance Log Book Contractor name Engineer name Site name Site number Hydrobox maintenance record sheet Warranty number Model number Serial number Mechanical Frequency Notes Isolate and drain hydrobox, remove mesh from internal strainer clean and replace. Open the pressure relief valve, check for unrestricted discharge to the tundish and that the valve reseats correctly.
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HEAD OFFICE : TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN Copyright 2011 MITSUBISHI ELECTRIC ENGINEERING CO., LTD. Distributed in Jul. 2011 No. OCH503 New publication, effective Jul. 2011 Made in Japan Specifications subject to change without notice...
