Power / Grounding Wiring And Fuses - WEG CFW-11 User Manual

Installation and Connection

3.2.2 Power / Grounding Wiring and Fuses

ATTENTION!
Use proper cable lugs for the power and grounding connection cables.
ATTENTION!
Sensitive equipment such as PLCs, temperature controllers, and thermal couples shall be kept at a
minimum distance of 0.25 m (9.84 in) from the frequency inverter and from the cables that connect
the inverter to the motor.
DANGER!
Improper cable connection:
- The inverter will be damaged in case the input power supply is connected to the output terminals
(U/T1, V/T2, or W/T3).
- Check all the connections before powering up the inverter.
- In case of replacing an existing inverter by a CFW-11, check if the installation and wiring is according
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to the instructions listed in this manual.
ATTENTION!
Residual Current Device (RCD):
- When installing an RCD to guard against electrical shock, only devices with a trip current of 300 mA
should be used on the supply side of the inverter.
- Depending on the installation (motor cable length, cable type, multimotor configuration, etc.), the
RCD protection may be activated. Contact the RCD manufacturer for selecting the most appropriate
device to be used with inverters.
NOTE!
The wire gauge values listed in table 3.2 are merely a guide. Installation conditions and the maximum
permitted voltage drop shall be considered for the proper wiring sizing.
Input fuses
Use High Speed Fuses at the input for the protection of the inverter rectifier and wiring. Refer to table 3.2
for selecting the appropriate fuse rating (I
the cold (and not the fusion) current extinction value).
In order to meet UL requirements, use class J fuses at the inverter supply with a current not higher than the
values of table 3.2.
Optionally, slow blow fuses can be used at the input. They shall be sized for 1.2 x the rated input current of
the inverter. In this case, the installation is protected against short-circuit, but not the inverter input rectifier.
This may result in major damage to the inverter in the event of an internal component failure.
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t shall be equal to or less than indicated in table 3.2, consider
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