13
When the distance between the inverter and the motor is longer than 100 meters, cable wires
should be carefully chosen to reduce the voltage loss due to wire resistance below 3%.
Voltage drop (V) =
√
3x Wire resistance (ohm/m) x wire length (m) x current.
(B)
Control circuitry wiring must be separated, terminated, and away from the primary
power circuitry and other high-voltage or large-current power lines to avoid noise interference.
To reduce the noise interference and avoid possible operational problems, shielded twisted
pair cable should be used to wire the low voltage DC control circuitry. Please refer to the
following diagram. Connect the shielding wire onto the grounding terminal. Only connect one
end of the shield to ground.
(C)
The grounding terminal of the inverter must be correctly grounded in compliance with
local codes or NEC requirements.
Grounding wire should be wired in accordance to electrical equipment (AWG) with the length
of the grounding wire as short as possible.
The grounding wire of the inverter must be grounded together with other large current loads
(such as soldering machines or large current motors). They should be grounded separately.
(D)
Wire specification, apply appropriate wire with correct diameter for primary power
circuitry and control circuitry in accordance with electricity regulations.
Wiring distance must be under 50m.
To inverter terminal
Connnect Shield
Connect to system grounding terminal
Wrapped with
insulating tape
Do not connect the shielding
wire at this end
To control machine
Insulation
Shielding
(a) good
(b) good
(c) not good
