Earth Leakage Circuit Breaker For Heater; Relay For Heater; Booster Heater - Mitsubishi Electric EHSC-VM2B Service Manual

Part Name

Earth leakage circuit breaker for heater

Relay for heater

R S T
U V W

Booster heater

Thermostat (90 °C) and thermal cut out (121 °C)
121 °C
Thermal
cut-out
9 10
2kW heater (230V, 1 phase)
1
2 + 4kW heater (230V, 1 phase)
2kW
1 2
3 + 6kW heater (400V, 3 phase)
1kW
1kW 1kW
1 2 3
3 + 6kW heater (230V, 3 phase)
1kW 1kW
1kW
1 2 3
OCH532A
A1 A2
90 °C
Manual reset
water
thermostat
2kW
2
2kW
2kW
3 4
2kW
2kW 2kW
4 5 6
2kW 2kW
2kW
4 5 6
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.
When the applied voltage is not 230V AC across the terminals A1-A2, check the terminals
R-U, S-V, and T-W are open.
When the applied voltage is 230V AC across the terminals A1-A2, check the terminals
R-U, S-V, and T-W are short.
Measure the resistance between the terminals with a tester.
Terminal
9-10 110(±35)mΩ
Terminal
1-2 26.5(+3/-1.3)Ω
Terminal
1-2 26.5(+3/-1.3)Ω
3-4 13.3(+1.5/-0.6)Ω
Terminal
1-2=2-3=1-3 105.8(+11.8/-5)Ω
4-5=5-6=4-6 52.9(+5.8/-2.5)Ω
Terminal Normal
35.3(+3.9/-1.8)Ω
1-2=2-3=3-1
4-5=5-6=6-4 17.6(+1.9/-0.9)Ω
64
Check Points
Normal Abnormal
Open or Short
Normal Abnormal
Open or Short
Normal Abnormal
Open or Short
Open or Short
Normal Abnormal
Open or Short
Open or Short
Abnormal
Open or Short
Open or Short