VFD68 Variable Frequency Drive (575 VAC) Installation Instructions
11
Precautions
Before you apply power to the VFD68 Drive and controlled motor, always recheck the following items:
•
Connect the VFD68 Drive only to three-phase induction motors. Connecting the VFD68 Drive to other electrical
equipment may cause damage.
•
Applying power to the output terminals (U, V, W) of the VFD damages the VFD. Never connect supply power to
the drive output terminals.
•
If you wire multiple motors to the VFD68 output, run separate wires to each motor. Do not use daisy-chain
wiring.
•
Do not install a power factor correction capacitor, surge suppressor, or capacitor type filter on the VFD output
side. These devices can cause the VFD to trip, or they can damage the capacitor and surge suppressor.
•
A high-voltage charge remains in the VFD electronic components for a short time after the power is switched
off.
Wait at least 10 minutes after the power supply has been switched off to allow the electric charge and heat to
dissipate. Using a voltmeter, make sure that the voltage across the main circuit ter and - of the VFD is
no more than 30 VDC.
•
A short circuit or earth (ground) fault on the VFD output side can damage the VFD.
-
Check the insulation resistance of the circuit before you operate the VFD; repeated short circuits may
damage the VFD. These short circuits may be caused by peripheral circuit inadequacy, an earth (ground)
fault due to wiring inadequacy, or reduced motor insulation resistance.
-
Check the ground (to-earth) insulation and phase-to-phase insulation of the VFD output side before
applying power.
Carefully check the motor insulation resistance, especially when the VFD is used with an old motor or a
motor located in unfavorable conditions.
•
Do not exceed the permissible voltage to the VFD I/O signal circuits.
Applying a voltage higher than the permissible voltage to the VFD I/O signal circuits, or applying voltage of
opposite polarity, may damage the I/O devices.
•
Do not short circuit the +VDC excitation voltage outputs (terminals 10 and PC) to common (terminals: 5 and
SD). Shorting the excitation voltage outputs to common may damage the VFD68.
•
Prevent VFD-generated EMI from causing functional problems.
-
Do not run the low-voltage signal cables and the high-voltage power cables in parallel with each other, and
do not bundle them together.
-
Run low-voltage signal cables as far away as possible from high-voltage power cables.
-
Use shielded cables for the low-voltage signal cables. Connect the sensor cable shield at only one point
and that one point is the same terminal as the sensor's common wire.
IMPORTANT:
Run all low-voltage wiring and cables separate from all high-voltage wiring. Shielded
cable is strongly recommended for input (sensor) and analog output cables that are exposed to high
electromagnetic or radio frequency noise.
IMPORTANT:
Electrostatic discharge can damage VFD68 Drives. Use proper electrostatic discharge
(ESD) precautions during installation and servicing to avoid damaging VFD68 Drives.
IMPORTANT:
Do not connect supply power to the VFD68 Drive before finishing wiring and checking all
wiring connections. Short circuits or improperly connected wires can result in damage to the drive and void
any warranty.
