Short Circuit Current Ratings
The maximum allowed short-circuit current at the input power connection is defined in UL 508C (now
UL-61800-5-1) as 100 kA. Depending on the selected over current protective device (OCPD), the
VFD's are suitable for use in circuits capable of delivering up to a maximum of 100 kA RMS
symmetrical amperes at the inverter's maximum rated voltage. The following table shows the
recommended circuit breaker frame (100F, 150F, etc.) and interrupt rating codes (EF, NF, etc.) for
various SCCR ratings (RMS symmetrical amperes). Select the appropriate breaker for the SCCR
requirements of the system.
480V Interrupt Rating Codes
EF = Standard Fault 25kA (100F Frame Size)
NF = Normal Fault 35kA (100F - 1200F Frame Size)
HF = High Fault 65kA (100F - 1200F Frame Size)
LF = Extra High Fault 100kA (150F - 1200F Frame Size)
PF = Standard Fault 50kA (1200F Frame Size)
•
Do not modify the interior workings of the inverter. Doing so will void the
warranty.
•
The inverter is designed for 3-phase motor operation. Do not use the inverter to
operate a single-phase motor.
•
Do not place heavy objects on top of electric cables. Doing so may damage the
cable and result in an electric shock.
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