3 WIRING
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(k) Wiring Distance between Inverter and Motor
If the total wiring distance between inverter and motor is excessively long and the inverter
carrier frequency (main transistor switching frequency) is high, harmonic leakage current
from the cable will adversely affect the inverter and peripheral devices.
Consider the wiring distance between inverter and motor when increasing the carrier fre-
quency value. Carrier frequency can be set by constant C6-02.
Table 2 Wiring Distance between Inverter and Motor
Wiring Distance between
Inverter and Motor
Up to 50m From 50m to 100m More than 100m
Carrier Frequency
(Set value of constant C6-02)
12kHz or less
(Max. 12)
8kHz or less
(Max. 8)
4kHz or less
(Max. 4)
(3) Grounding
S Ground resistance
200V class : 100Ω or less, 400 V class : 10Ω or less.
S Never ground the inverter in common with welding machines, motors, or other large-
current electrical equipment.
S Use the ground wires described in Table 5 or 6 and keep the length as short as possible.
S When using several inverter units side by side, ground the units as shown in Fig. 15,
(a) or (b). Do not loop the ground wires as shown in (c).
(a) Acceptable
(c) Not Acceptable
(b) Acceptable
Fig. 15 Grounding of Three Inverter Units
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