CV7300 Instruction Manual - TECO-Westinghouse Motor Company

Chapter 3 Ambient Environment and Installation
When the connection between the inverter and the motor is too long, consider the
voltage drop of the circuit. Phase-to-phase voltage drop (V) =
3 ×resistance of wire (Ω/km)×length of line (m)×current×10 -3 . And the number of
carriers must be adjusted based on the length of the line.
The length of the line between
Below 25m Below 50m Below 100m Over 100m
the inverter and the motor
Number of carriers allowed Below 16KHz Below 12KHz Below 8KHz Below 5KHz
Settings of 3-22parameter 16 12 8 5
(B) The wiring of the control circuit must be separated and routed away from the main circuit
control line or other high voltage or current power lines to avoid noise interference
To avoid error actions caused by noise interference, shield the control circuit wiring
with a twisted wire, and connect the shielded wire to a ground terminal. Refer to the
figure below.
The wiring distance should not exceed 50 m.
To ground terminal
(refer to instructions of
filter wiring
Shielding Wire Protective
Wrapped with insulating
3-10
Do not connect this end
(C) Ground the ground terminal of the inverter properly. For 200V class ground 100Ω or less;
for 400V class ground 10Ω or less.
Ground wiring is based on the electrical equipment technical basis (AWG). The shorter,
the better.
Do not share the ground of the inverter to other high current loads (welding machine,
high power motor). Connect the terminals to ground respectively.
Do not make a loop when several inverters share a common ground point.
(a) Good (b) Good (c) Bad
(D) To ensure maximum safety, use proper wire gauges (AWG) for the main power circuit and
control circuit according to relative regulations.
(E) After wiring, check that the wiring is correct, wires are intact, and terminal screws are
secured.