Mitsubishi Electric EHGT17D-YM9ED, Service Manual

Page: 57 / 98

Part Name Checkpoints
Booster heater Measure the resistance between the terminals with a tester.
Thermostat (90°C) and thermal cut out (121°C)
90 °C
Manual reset
water
thermostat
121 °C
Thermal
cut-out
AWG18 AWG18
9
10
Terminal Normal Abnormal
9–10 110(±35) mΩ Open or Short
3 + 6 kW heater (400 V, 3 phase)
5 6
AWG13 FEP BLUE AWG13 FEP BLUE
AWG15 FEP WHITE
2kW
4
AWG13 FEP BLUE
2kW 2kW
2 3
1kW
1
1kW 1kW
AWG15 FEP WHITE AWG15 FEP WHITE
Terminal Normal Abnormal
1−2=2-3=1−3 105.8(+11.8/−5) Ω Open or Short
4−5=5-6=4−6 52.9(+5.8/−2.5) Ω Open or Short
Earth leakage circuit breaker for heater If a short circuit occurs on the booster heater, immersion heater, or each power
line, a short-circuit breaker will trip and power source will be blocked.
Eliminate the causes of short circuit and then turn on the breaker again.
Relay for heater
R S T A1 A2
U V W
When the applied voltage is not 230 V AC across the terminals A1-A2, check
the terminals R-U, S-V, and T-W are open.
When the applied voltage is 230 V AC across the terminals A1-A2, check the
terminals R-U, S-V, and T-W are short.
57
OCH722A