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1) Motor Coil Inspections |
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1. |
Turn power of unit off. |
2. |
Use tester unit to measure resistance range (Ω) |
3. |
Measure resistance of U1 ~ V1, U1 ~ W1, V1 ~ W1. (see left illustration for reference) |
4. |
If all three phases have the same resistance (Ω), the motor coil is normal. |
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If the resistance values are unbalanced, the motor coil is defective. |
Note: |
Even if the resistance of the motor coil is normal, thermal relay may trip depending of hardness of motor shaft bearing. |
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Motor pumps will require overhaul. |
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2) Motor Relay Inspections |
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1. |
Turn power of unit off. |
2. |
Remove U1, V1, W1 on motor lines from thermal relays. |
3. |
Set motor thermal relays. |
4. |
Use tester to measure AC voltage range. |
5. |
Turn power on and turn MS-1 relay on. |
6. |
Measure voltage of U1 ~ V1, U1 ~ W1, V1 ~ W1. (see left illustration for reference) |
7. |
If all three phases have AC-200 running, the motor coil is normal. |
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If the AC voltage values are unbalanced, the relay or the thermal relays are defective. |
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3) Heater Inspections |
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1. |
Turn power of unit off. |
2. |
Use tester unit to measure resistance range (Ω). |
3. |
Measure resistance of H1 ~ H2, H1 ~ H3, H2 ~ H3. (see left illustration for reference) |
4. |
If all three phases have the same resistance (Ω), the heater coil is normal. |
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If the resistance values are unbalanced, the heater coil is defective. |
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4) Heater Relay Inspections |
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1. |
Use tester to measure AC voltage. |
2. |
Turn power on and turn the MC-1 relay on. |
3. |
Measure voltage of H1 ~ H2, H1 ~ H3, H2 ~ H3. (see left illustration for reference) |
4. |
If all three relay phases of H1, H2 and H3 have AC-200 running, the heater relay is normal. |
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If the AC voltage values are unbalanced, the relays are defective. |
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