NO.3 Wiring
11
1. Main circuit wiring
● During wiring, please select wire diameter specification and conduct wiring as per those
specified by electrical engineering laws so as to ensure the safety.
● For power supply wiring, prefer shielded wire or spool, and earth isolating layer or both
ends of spool.
● Be sure to install air circuit breaker NFB between the power and input terminal (L1.L2.L3).
(In case of applying leakage switch, please use the breaker with high frequency solution)
● Do not connect AC power to inverter output terminal (U.V.W).
● Prevent output wire touching metallic part of inverter housing; otherwise, earth short-circuit
may be induced.
● Do not apply phase-shifting capacitor, LC, RC noise filter or other elements to output end of
inverter.
● Indispensably make main circuit wiring of inverter away from other control equipment.
● When the wire between inverter and motor exceeds 15m (220V grade) or 30m (380V
grade), extremely high dV/dT shall emerge inside motor coil and it shall produce damage to
layer insulation of the motor, so it is necessary to use AC motor dedicated to inverter or install
reactor onto inverter side.
● In case of long distance between inverter and motor, reduce carrier frequency, for the
larger the carrier frequency is, the larger the higher harmonic leakage current becomes,
which shall produce adverse effect on the inverter and other equipment.
2. Control circuit wiring
● It is not allowed to place signal wire and main circuit wire inside the same slot.
● Supply cord of signal wire should be shielded wire with the size of 0.5-2.0mm.
● Control terminal on control board should be correctly used as required.
3. Earth wire
● Please properly earth terminal PE of earth wire.
220V grade: The third type earthing (earthing resistance is below 100)
380V grade: Particularly the third type earthing (earthing resistance is below 10)
● Use earth wire as per fundamental length and size specified by electrical equipment
technology.
● Absolutely avoid sharing earth electrode with welding machine, power generating machine
and other large-scale power equipment and make earth wire away from power line of
large-scale equipment as much as possible.
● Earth wire must be short to the utmost extent.
