28
Variable Frequency Drive (VFD)
Consult the VFD manual and all documentation shipped with the unit for proper installation and wiring of
the VFD. The VFD has been programmed by the factory with ordered specific parameters. Use
as a guide during installation.
Variable Frequency Drive (VFD) Installation
Input AC Power
•
Circuit breakers feeding the VFDs are recommended to be thermal-magnetic and fast-acting. They
should be sized based on the VFD amperage and according to
. Refer to the
installation schematic for exact breaker sizing.
•
Every VFD should receive power from its own breaker. If multiple VFDs are to be combined on the
same breaker, each drive should have its own protection measure (fuses or miniature circuit breaker)
downstream from the breaker.
•
Input AC line wires should be routed in conduit from the breaker panel to the drives. AC input power to
multiple VFDs can be run in a single conduit if needed.
Do not combine input and output power
cables in the same conduit.
•
The VFD should be grounded on the terminal marked PE. A separate insulated ground wire must be
provided to each VFD from the electrical panel. This will reduce the noise being radiated in other
equipment.
ATTENTION: Do not connect incoming AC power to output terminals U, V, W. Severe damage to the
drive will result. Input power must always be wired to the input L terminal connections (L1, L2, L3).
WARNING!!
- Before installing the VFD drive, ensure the input power supply to the drive is OFF.
- The power supply and motor wiring of the VFD must be completed by a qualified electrician.
- The VFD is factory programmed, only change if replaced or ordered separately.
Table 11 - VFD Installation Check List
Check
Off
Description
The installation environment conforms to the VFD manual.
The drive is mounted securely.
Space around the drive meets the drive’s specification for cooling.
The motor and driven equipment are ready to start.
The drive is properly grounded.
The input power voltage matches the drive’s nominal input voltage.
The input power connections at L1, L2, and L3 are connected and tight.
The input power protection is installed.
The motor power connection at U, V, and W are connected and tight.
The input, motor, and control wiring are run in separate conduit runs.
The control wiring is connected and tight.
NO tools or foreign objects (such as drill shavings) are in the drive.
NO alternative power source for the motor (such as a bypass connection) is connected - NO
voltage is applied to the output of the drive.