times, change speed at certain temperatures, interface with a fire sprinkler system, etc.
Instructions for mounting and wiring the control panel are supplied with the control panel.
5.2 Wiring
5.2.1 General considerations
VFDs can induce voltage spikes that can be harmful to motors. They can also create
electrical noise and RF( radio frequency) that can interfere with low voltage control wiring
machines, computers networking lines, radios, etc. there are a variety of filters,
reactors, isolators, etc. that can deal with these type of problems. However most of these
problems can be avoided by observing the following guide lines:
（1）
Never allow the conduit to run between the MCP and the fan or to exceed 30 meters on
480V,
or 40 meters on 220V. Excessively long runs between the MCP and the fan can amplify
the voltages spikes created by the VFD.
（2）
Never use larger wire than code requires. Excessively large wire can also amplify the
voltages spikes.
（3）
Put the wires to each fan in separate grounded metallic conduit. Do not bundle them
together with the power wires going into the control panel, or with wires going to other fans. Use a
section of flex conduit between the building structure and the fan to accommodate
fan movement.
（4）
Be sure to pull 4 wires; you need 3 for power, and 1 for ground.
（5）
Alternatively, you can use 4 conductor shielded cable. When using shielded cable,
ground one only to avoid ground loops that can negate the ground effect.
（6）
Separate fan wires (cable or conduit) from other wires running parallel (especially
low voltage control wires) by at least 6 inches.
5.2.2 Grounding
Always run a separate ground wire from the fan motor. Do not rely on the motor being
grounded through the fan mount or the conduit. The ground wire from the motor should be
grounded at the same space as the ground from the VFD. That may be the control panel
if it is mounted to a well grounded steel beam or column. If not, the ground wire from the
motor and the VFD can be connected together, along with a wire grounding the control.
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