Vacon 50X, User Manual

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connections vacon 26
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4.2.5 Single-phase Operation
Vacon 50X AC drive 230 Vac models are designed for both three-phase and singlephase input power. If
one of these models is operated with single-phase power, use any two line input terminals. The output of
the device will always be three-phase.
The safe derating of the Vacon 50X series of drives is 50% of the nominal current (hp) rating. Consult the
factory with the particular application details for exact derating by model.
4.2.6 Ground Fault Circuit Interrupters
Vacon 50X drives rated for 230 Vac are not designed to operate with ground fault circuit interrupters (GF-
CI). The GFCI breakers are designed for residential use to protect personnel from stray currents to
ground. Most GFCI breakers will shut off at 5 mA of leakage. It is not uncommon for an AC drive to have
30 to 60 mA of leakage.
4.2.7 Motor Lead Length
The distance from the Vacon 50X drive to the motor should not exceed 300 meters. If the leads for motor
connections exceed 30 meters, the motor windings may be subjected to voltage stresses two to three
times nominal values unless an output filter is utilized. Consult with the motor manufacturer to ensure
compatibility. Line disturbance and noise can be present in motor wiring of any distance. The carrier fre-
quency for the drive should also be reduced using parameter 803 (PWM Frequency).
Nuisance trips can occur due to capacitive current flow to ground.
Some applications can have a restricted lead length because of type of wire, motor type, or wiring place-
ment. Consult VACON and the motor manufacturer for additional information.
4.2.8 Using Output Contactors
Contactors in the output wiring of an AC drive may be needed as part of the approved safety circuit. Prob-
lems can arise if these contactors are opened for the safety circuit and the drive is left in run mode of
operation. When the contactor is open, the drive is in a no-load, no-resistance state, but is still trying to
supply current to the motor. However, when the contactor closes, the drive sees the motor resistance and
instantly demands current. This inrush of current when the contactor closes can fault or cause failure to
the drive.
To prevent problems, interlock an auxiliary contact to the drive's Run or Enable circuit to stop the drive
when the contactor opens. In this way, the drive will be disabled and no inrush will occur when the con-
tactor is closed again.