Precautions - PENN Controls - VFD68Bxx - VFD68Cxx - Three‐Phase Motor Speed Controller - VFD68 Three‐Phase Variable Frequency Drive

VFD68 Variable Frequency Drives (230 or 460 VAC) Installation Guide

PENN Controls
Product name
VFD68 Three‐Phase Variable Frequency Drive
Document type
Installation Guide
Part number
Document revision
Revision date

Before you apply power to the VFD68 Drive and controlled motor, always recheck the following items:

  • Connect the VFD only to three-phase induction motors. Connecting the VFD to other electrical equipment may cause damage.
  • Application of power to the output terminals (U, V, W) of the VFD will damage the VFD. Never connect supply power to the drive output terminals.
  • If you wire multiple motors to the VFD 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 terminals + 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.

    Application of 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 VFD.
  • 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.
    • Install a ferrite core on the signal cable (for example, ZCAT3035-1330 TDK).