1hp VFD blowing 1 of the line fuses.

[steve66]

The voltage drop caused by the length of wire increases the amount of current seen at the 2nd fuse in series. So if the current at the load is 7A, the closest 6A fuse sees 7A, the upstream fuse sees slightly less because the voltage is a little higher there. The 2nd fuse in series blows first.

Jraef:

I'm not sure you have had your coffee yet. The current is the same throughout a series circuit.

Even if it was a little less at the second fuse, the tolerance of the fuses would probably be a lot higher than the difference in current.

Steve

 

[skeshesh]

I have to agree with Steve on this one. The voltage drop increases as the resistance of the circuit increases due to an increase in the lenght of the conductor. The current for most purposes remains a constant.
I've been reading around relative to this post and there are several possibilities. I don't have the level of experience to make a call but am waiting eagerly to learn the answer as this issue gets resolved.

 

[petersonra]

As often as not, the components seem to open to protect the fuse.

 

[Jraef]

Jraef:

I'm not sure you have had your coffee yet. The current is the same throughout a series circuit.

Even if it was a little less at the second fuse, the tolerance of the fuses would probably be a lot higher than the difference in current.

Steve

D'oh!:roll:

Note to self: apply brain before replying....