Input Power Conditioning; Supplying Input Power From A Variac (Variable Transformer) - ABB MicroFlex e150 User Manual

Input power conditioning

Certain power line conditions must be avoided; an AC line reactor, an isolation
transformer or a step up/step down transformer might be required for some power
conditions:
• If the feeder or branch circuit that provides power to the MicroFlex e150 has
permanently connected power factor correction capacitors, an input AC line
reactor or an isolation transformer must be connected between the power factor
correction capacitors and the MicroFlex e150 to limit the maximum symmetrical
short circuit current to 5000 A.
• If the feeder or branch circuit that provides power to the MicroFlex e150 has
power factor correction capacitors that are switched on line and off line, the
capacitors must not be switched while the drive is connected to the AC power line.
If the capacitors are switched on line while the drive is still connected to the AC
power line, additional protection is required. A Transient Voltage Surge
Suppressor (TVSS) of the proper rating must be installed between the AC line
reactor (or isolation transformer) and the AC input to the MicroFlex e150.
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Supplying input power from a variac (variable transformer)

When AC power is supplied from a variac, the MicroFlex e150's pre-charge circuit
might not operate correctly. To ensure that the pre-charge circuitry operates correctly,
increase the variac voltage to the desired level and then power cycle the 24 V DC
control circuit supply. This will restart the pre-charge circuit and allow it to operate
correctly.
Electrical installation: AC input, motor and brake 47