Proper Fuse Breaker And Wire Sizing For The SMV Variable Frequency Drive (VFD)

About This Video

Many callers ask what size fuses or breakers they should use when wiring their variable frequency drive (VFD). This video covers how to properly size your variable frequency drive’s fuses or breakers. It also recommends what kind of fusing you should use.

Video Transcript

Warning: All electrical equipment should be handled by qualified electricians. Make sure to adhere to all local, national, and international safety laws when handling your equipment. Failure to do so could result in severe injury or even death.

[Let’s look at the] fusing chart on in the manual. If I pull it up it actually does it all based on part number. So when I pull up this part number on the side of my drive, it is ESV-371-N01-SXB. So then I just look that up here: ESV 371 N01 SXB. I follow that chart across to the right.

I have a couple options here. I can use a 16 amp fuse, use a 15 amp breaker, [or a] 15 amp fuse. It even gives me a recommended part number for my fuse. It recommends 14 gauge wire. I mean that’s pretty much all I need to know. Now the reason the fusing is a lot higher than the rated output current of the drive is because it’s rated for over-current.

So [for] recommended fuses we usually recommend fast blow fuses. That’s going to be your ideal protection. Obviously, a breaker is going to be a lot slower in reacting to an over-current situation. Standard fuses also can be a lot slower in reacting. The more time it takes for it to react the more potential damage can be caused to the drive as a result of whatever the overcurrent is.

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