Periodic Maintenance Inspections - Mitsubishi Electric CAHV-R450YA-HPB Service Manual

[ IX Maintenance ]

[1] Periodic maintenance inspections

IX Maintenance
Periodically check the refrigerant circuits, circulating-water circuits, and the entire electronic parts.
Check items
Check item
1. Around the unit
(Twice/year)
2. Refrigerant system
(Twice/year)
3. Compressor
4. Protection device
(Twice/year)
5. Electrical system
(Twice/year)
6. Hot water system
(Twice/year)
7. Air-side heat exchanger
(Twice/year)
*1 Pipe temperature reading of the water-side heat exchanger refrigerant temperature sensor at the sensor installation point.
*2 Pipe temperature reading of the air-side heat exchanger refrigerant temperature sensor at the sensor installation point.
HWE22020
Check point
1. Check for debris such as dust and fallen leaves.
2. Check for loose screws and bolts.
3. Check for rust.
4. Check the thermal and sound insulator for peeling off. Visual check
5. Check for abnormal sound and vibration.
1. Check for gas leakage.
2. Check the pipes and capillary tubes for resonance.
3. Check the valves (expansion, solenoid, four-way
valve, etc.) for proper operation.
4. Condensing temperature
Substitute the outlet pipe temperature of the water-side
heat exchanger *1 during heating for the condensing tem-
perature
5. Evaporating temperature
Substitute the outlet pipe temperature of the air-side
heat exchanger *2 during heating for the evaporating
temperature
1. Check the operating current.
2. Check for abnormal sound and vibration.
3. Check the start-stop interval.
1. Check the high-pressure switch for proper operation.
2. Check the pump interlock for proper operation.
1. Check the terminal screws for loosening.
2. Check the contact for cleanliness and abnormality.
3. Check the conductors and relays for proper operation.
4. Check the operation circuit for proper insulation resis-
tance.
5. Check the main circuit for proper insulation resis-
tance.
6. Check the ground wire for proper connection.
7. Check the wires inside the unit for disconnection and
loosening.
1. Check that the water is clean.
2. Check that the water pressure is appropriate.
3. Check for water leakage.
4. Check the pump for head loss during stoppage.
5. Check the water-side heat exchanger and pipes for air
pockets.
6. Check the water pump for proper voltage and current.
7. Check for proper water flow rate.
8. Test the water quality.
1. Check the fins for corrosion.
2. Check the fins for debris.
Standard
Visual check
Visual check
Apply anti-rust agent as necessary.
Use a gas leak tester.
Visual check
See the check content of the parts and "
lines for Maintenance and Inspection of Major
Parts
."
Outlet water temperature during heating + (0 - 5°C)
Intake air temperature during heating - (3 - 8°C)
Compare with the rated current value.
Immediately stop the operation and inspect the com-
pressor if abnormal sound or vibration from the com-
pressor or other parts are noticed. Visually check for
debris.
10 minutes or longer between startup and restart
Conduct an operation check.
Conduct an operation check.
Check each one with a screwdriver.
Visual check
Check the operation of the relays.
5 Mohm or above when measured with a 500 V ohmme-
ter
10 Mohm or above when measured with a 500 V ohm-
meter
Visual check
Check with a screwdriver.
Check the strainers in the water pipes.
1.0 MPa or below
Visual check
Open the air-vent valves to make sure no air comes out.
(Install the air-vent valves for the pipes on site.)
Water quality standard
Visual check
Clean the heat exchanger if the high pressure has risen
by 0.1 MPa under the same given conditions (evaporat-
ing temperature, outside temperature).
- 121 -
IX [2] Guide-
GB