Disassembly Procedure - Mitsubishi Electric EHGT17D-YM9ED Service Manual

SW2 setting
Brine inlet temperature (TH32)
−39 to 88
ON
1 2 3 4 5 6
Borehole freeze prevention status
ON
1 2 3 4 5 6
Brine outlet temperature (TH34)
−39 to 88
ON
Heating: TH6
Cooling: T
1 2 3 4 5 6
10

DISASSEMBLY PROCEDURE

<Service Precautions>
Before beginning any service you must confirm the following precautions and instructions.
1. Be sure to turn off the power supply before service.
2. Take care when you handle heavy items.
3. When welding, be sure to perform non-oxidation welding.
4. Do not burn lead wires and insulators when detaching brazing portions.
5. Pipe edges, flange surfaces, sealing surfaces, screws, and pipe covers must not have any damages.
6. Do not release hydrofluorocarbon. Be sure to recover hydrofluorocarbon to prevent global warming when exchanging the parts of the
refrigerant circuit.
7. Make sure the locks of connectors and terminals are engaged when inserting them. They must not be loosened.
8. Connectors and terminals must not have any damage or dirt.
9. When routing wires,
● do not apply load to lead wires, the edges of lead wires, the connectors, and the controller board.
● do not let them touch pipes, the edges of the plate, and the mounted parts on the controller board.
● do not trap them between sheet metals.
10. Do not fold the wires as it may cause their breakage.
11. Make sure the controller boards are fixed down to the support and free from looseness.
12. Do not give any shock on the controller board.
13. Any dust must not be attached on the controller board.
14. Do not damage the mounted parts on the controller board.
15. The wires must not move after being bundled with a cable strap.
16. When bundling wires with a fastener, be sure to fasten them without looseness.
+30
17. Fasten bands at 90 N of tightening force.
0
18. Cut off excess bands.
19. When removing bands, obtain them locally to replace.
20. When replacing an O-ring, use the suitable one for each part.
● For the brine pump and the flow sensor: E210 (manufactured by NOK)
● For the flow switch: XVH756 (SIKA)
● For the 3-way valve and the drain cock [DHW tank]: P16 E210 (NOK)
● For the other parts: P22 E210 (NOK)
Apply grease (KS-651 8 [Shin-Etsu Chemical Co.]) at the portion to put O-rings.
21. When replacing a gasket, use the suitable one (the size and the use) for each part.
● G1", G3/4", G3/8", and G1/4" gasket for water: G1", G3/4", G3/8", and G1/4" (NICHIAS Corporation)
● G1" gasket for brine: G1" (PTFE) (NICHIAS Corporation)
22. Make sure of no moisture or water on the controller boards, the electrical parts, and the connectors.
23. Assemble the parts in the opposite order of disassembly.
24. Put the lead wire and the connector in the right place refer to the page 89 when the lead wire routing/fixing and the connection to the
connector.
OCH722A
Display detail
63HS
Explanation for display
−39 to 88
(When the temperature is 0°C or less, "–" and
temperature are displayed by turns.)
(Example) When –15°C;
0.5 s
Display Status
0 No restriction
1 Stage A
2 Stage B
3 Stage C
4 Stage D
5 COMP OFF
−39 to 88
(When the temperature is 0°C or less, "–" and
temperature are displayed by turns.)
(Example) When –15°C;
0.5 s
78
Unit
:
0.5 s 2 s
15
─
:
0.5 s 2 s
15