Units In The Heating Mode Do Not Operate At Expected Capacity - Mitsubishi Electric PUHY-M200YNW-A1 Service Handbook

Table of Contents
[8-3 Refrigerant Control Problems ]
8-3-2

Units in the Heating Mode Do Not Operate at Expected Capacity.

1. Phenomena
Although heating operation starts with the normal remote controller display, the capacity is not enough.
2. Cause, check method and remedy
1.
Compressor frequency does not rise sufficiently.
Faulty detection of pressure sensor.
Protection works and compressor frequency does
not rise due to high discharge temperature
Protection works and compressor frequency does
not rise due to high pressure.
ON
1
2
3
4
5
6
7
8
9 10
12
- chapter 8
Cause
The figure at left shows that the switches 1 through 5 are set to ON and 6 through 10 are set to OFF.
Check method and remedy
(1)
Check pressure difference between the detected
pressure by the pressure sensor and the actual
pressure with self-diagnosis LED.
→ If the accurate pressure is not detected, check
the pressure sensor.
Refer to the following page(s). [8-5-1 Comparing
the High-Pressure Sensor Measurement and
Gauge Pressure]
Note:
Higher inlet pressure by the high pressure sensor
than the actual pressure causes insufficient capac-
ity.
SW4 setting (SW6-10: OFF)
High pressure sensor
ON
SW4
1
Low pressure sensor
ON
SW4
1
(2)
Check the difference between the condensing tem-
perature (Tc) and the target condensing tempera-
ture (Tcm) with self-diagnosis LED.
Note:
Higher Tc than Tcm causes insufficient capacity.
SW4 setting (SW6-10: OFF)
Condensing temperature Tc
ON
SW4
Target condensing temperature Tcm
ON
SW4
Note:
Protection works and compressor frequency does
not rise even at lower Tc than Tcm due to high dis-
charge temperature and high pressure.
At high discharge temperature:
Refer to the following page(s). [7-3-1 Error Code
[1102]]
At high pressure:
Refer to the following page(s). [7-3-3 Error Code
[1302] (during operation)]
2
3
4
5
6
7
8
9 10
2
3
4
5
6
7
8
9 10
1
2
3
4
5
6
7
8
9 10
2
3
4
5
6
7
8
9 10
1
BS_08_E

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