3-23
3.3.6 Ground connection
Inverter ground terminal must be connected to installation ground correctly and
according to the required local wiring regulations
Ground cable size must be according to the required local wiring regulations. Ground
connection should be as short as possible
Do not share the ground of the inverter with other high current loads (Welding machine,
high power motors). Ground each unit separately
Ensure that all ground terminals and connections are secure
Do not make ground loops when several inverters share a common ground point.
Please leave at least 5cm while installing inverter side by side in order to provide enough
cooling space.
(a) Corrent (b) Correct (c) Incorrect
Input power cable length
The length of the cables between the power source and/or the motor and inverter can
casue a significant phase to phase voltage reduction due to the voltage drop across the
cables. The maximum voltage drop is 2%, if this value is exceeded, a wire size having large
diameter is needed. To calculate phase to phase voltage drop by the following formula.
Phase-to-phase voltage drop(V)＝
3 ×resistance of wire(Ω/km)×length of line(m)×current (A) ×10
-3
Installing an AC line reactor
If the inverter is connected to a large-capacity power source (600kVA or more), install an
optional AC reactor on the input side of the inverte, it can improve the power factor on
the power supply side.
Cable length & Carrier frequency
The followable setting of the PWM carrier frequency is also determined by motor cable
length and is specified in the following table.
Cable length of motor
in m (ft.)
＜30m
(100)
30m ~ 50m
(100~165)
50m ~100m
(166~328)
≧100m
(329)
Recommanded carrier
frequenc allowed
parameter 11-01
16kHz(max) 10kHz(max) 5kHz(max) 2kHz(max)
※ The minimum carrier frequency of SLV control mode is 4K, please confirm the cable length.
To Next Page
Loading...
