Mitsubishi Electric LGH-F300RVX2-E Handbook page 39

(5) Temperatures and thermistor resistance table
Temperature Resistance
value (kΩ)
(°F) (°C)
-22 -30 64.2 to ∞ 19.4
-4.0 -20 37.2
-2.2 -19 35.3
-0.4 -18 33.5
1.4 -17 31.8
3.2 -16 30.2
5.0 -15 28.7
6.8 -14 27.3
8.6 -13 26.0
10.4 -12 24.7
12.2 -11 23.6
14.0 -10 22.4
15.8 -9 21.4
17.6 -8 20.4
* Measure the return air (RA) thermistor resistance across pin No. 1 and 2 of CN5, and the outdoor air (OA)
thermistor resistance across pin No. 1 and 3 of CN7.
(6) Motor resistance table
Cautions:
• Before disconnecting the motor connectors, make sure that the power is turned OFF and the circuit
board is discharged adequately.
• Even after the power supply is cut off, the capacitor is charged. Therefore, high voltage is applied to
the motor for a while. Make sure that the LEDs on the circuit boards are turned OFF before starting
work.
• Never touch the circuit board while the power is ON. It causes electric shock and failure of the unit.
Replace the fan motor in the following cases.
[1] If it is hard to rotate the motor shaft by hand
[2] If the resistance between the motor leads is significantly different from the values specified in the table below
*Before measuring the resistance, the motor connectors must be disconnected from the circuit board.
<LGH-F300RVX2-E, LGH-F380RVX2-E>
Supply fan motor
Pin No.
Exhaust fan motor
Normal resistance
<LGH-F470RVX2-E, LGH-F600RVX2-E, LGH-F940RVX2-E, LGH-F1200RVX2-E>
Supply fan motor
Pin No.
Exhaust fan motor
Normal resistance
Supply fan motor connector
Temperature Resistance
value (kΩ)
(°F) (°C)
-7 19.4
21.2 -6 18.5
23.0 -5 17.7
24.8 -4 16.9
26.6 -3 16.1
28.4 -2 15.4
30.2 -1 14.7
32.0 0 14.0
33.8 1 13.4
35.6 2 12.8
37.4 3 12.3
39.2 4 11.8
41.0 5 11.3
42.8 6 10.8
44.6 7 10.3
3-1
4-1
About 815 kΩ
3-1
4-1
∞ kΩ
Temperature Resistance
value (kΩ)
(°F) (°C)
46.4 8 9.9
48.2 9 9.5
50.0 10 9.1
51.8 11 8.7
53.6 12 8.4
55.4 13 8.0
57.2 14 7.7
59.0 15 7.4
60.8 16 7.1
62.6 17 6.8
64.4 18 6.6
66.2 19 6.3
68.0 20 6.1
69.8 21 5.8
71.6 22 5.6
3-4
4-5
About 40 kΩ
3-4
4-5
About 50 kΩ
Exhaust fan motor connector
─ 39 ─
Temperature Resistance
value (kΩ)
(°F) (°C)
73.4 23 5.4 100.4
75.2 24 5.2 102.2
77.0 25 5.0 104.0
78.8 26 4.8 105.8
80.6 27 4.6 107.6
82.4 28 4.5 109.4
84.2 29 4.3
86.0 30 4.2 113.0
87.8 31 4.0 114.8
89.6 32 3.9 116.6
91.4 33 3.7 118.4
93.2 34 3.6 120.2
95.0 35 3.5 122.0
96.8 36 3.3
98.6 37 3.2
3-5
4-6
About 105 kΩ ∞ kΩ
3-5
4-6
About 150 kΩ ∞ kΩ
Temperature Resistance
value (kΩ)
(°F) (°C)
38 3.1
39 3.0
40 2.9
41 2.8
42 2.7
43 2.6
111.2 44 2.5
45 2.5
46 2.4
47 2.3
48 2.2
49 2.2
50 2.1
194 90 0 to 0.7
3-6
4-7
3-6
4-7