EC-fan High-voltage Tests
1. Check Fuses. If fuses are okay, perform the following:
• Check all connections.
• Make sure connections are onthe wire strand and not onthe wire insulation.
• Cycle Power. Disconnect mains voltage to power down the motor and thenre-apply power.
• Check mainsvoltage at eachphase (phase toground) at the KL1 connector. Confirm phase failure
not present.
• Check that the voltage is within the acceptable voltage range at the KL1 connector. Confirm line
under-voltage isnot present.
2. Check Fuses. If fuses are blown, perform the following:
• Check resistances across the phases at the KL1 connector and note them inthe following table..
NOTE: Power wires must be removed from the motor for resistance test.
L1 -L2 Ohm
L2 -L3 Ohm
L1 -L3 Ohm
• Resistances should be similar for all 3 readings.
• Resistance readings should be greater than 2Ohm.
• Check all connections. Make sure connections are onthe wire strand and not onthe wire
insulation.
• Replace Fuses.
• Check mainsvoltage at eachphase (phase toground) at the KL1 connector. Confirms phase
failure not present.
• Check that the voltage is within the acceptable voltage range at the KL1 connector. Confirmsline
under-voltage isnot present.
Vertiv | Liebert® CW™Installer/User Guide
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