ECN Forum Forums General Topics of the Trade General Discussion Area industrial control wiring

A warm hello to all:

Is there any benefit for fusing the neutral on a 120vac control circuit. I see a lot of this.

Am I wrong to think of this as similar to a 120vac breaker box....

Carl

Control circuits are no different than any other electrical circuit.

You never fuse a grounded conductor. OCPDs that open the grounded and hot conducters simultaneously are allowed.

Carl,
Is the control circuit a grounded circuit? There is a lot of 120 volt ungrounded control circuits out there.

I have seen both, can you eleaborate on both situations?

Carl

Ctolbert;
I know it was common practice years ago, but today they usually ground oneside of the seccondary and fuse the other on a control circuit. On 480 volt control, I think they still do because of both conductors being hot. The old drum controllers especially for cranes were not fused if there were a problem the operator would pull the main disconnet right behing him.

You have to watch European equipment for fusing on the neutral side they seem to do this a lot and can cause a great deal of problems for North American Electricians who don't realize it.

Resqcapt19 is right. As an industrial electrician I see a lot of ungrounded secondaries out there. I ground all I find. If the secondary is not grounded and one shorts it to ground, then fireworks and some real frazzled nerves. That's why the "neutral" side was fused. By the way Resqcapt19 are you a volunteer firefighter?

[This message has been edited by spkjpr (edited 11-22-2001).]

Spkjpr,
I'm now the assistant chief of a volunteer civil defense fire/rescue squad. I've been with the squad since 1969. The screen name is a few years old when I was a captain. The 19 is my gear number. We provide mutual aid rescue, fire fighting, air supply and lights at larger incidents.
Don