katan840df
Member
- Location
- Grand Rapids, MI
Is there a minimum wire awg size that I have to use when wiring a 3-phase motor with a PowerFlex 525 Variable Frequency Drive?
480VAC motor wiring minimum wire awg with vfd
- Thread starter katan840df
- Start date
- Status
- Location
- Bremerton, Washington
Of course, yes. The type of drive does not matter, its based on motor HP.
Part X - Adjustable Speed Drive Systems in Art 430 is a good place to start, in particular 430.122 Conductors Minimum Size and Ampacity
Why would you think there would not be a minimum size?
Part X - Adjustable Speed Drive Systems in Art 430 is a good place to start, in particular 430.122 Conductors Minimum Size and Ampacity
Why would you think there would not be a minimum size?
katan840df
Member
- Location
- Grand Rapids, MI
Sorry, let me clarify... I know that there is a min. size, but I thought the min. was 14 AWG for a 3-phase 480VAC motor. My application is a 1hp motor with a 1.56 FLA. The motor came in on a piece of equipment with 20awg wire, and I did not think that was correct.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
If the 20 gauge wire is factory installed it's not your concern as long as this equipment is listed and approved. If it's not listed and approved that is another matter. #14 is minimum size for motor wiring
katan840df
Member
- Location
- Grand Rapids, MI
Thank you - Is #14 min. size for motor wiring in code or more of an industry standard?
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
14ga is the minimum we can use IN THE FIELD, which is what the NEC is all about. FACTORY built and listed assemblies have their own standards. Under UL508A, INTERNAL Motor Branch Circuits under 5A can use 20ga wire. Field wiring under UL508A is still 14ga though, so it might be a stretch to call the wire from a control panel to a motor "internal". I know my UL inspector would not.
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