ECN Forum
Posted By: Admin No-Blow Fuses - 12/23/03 10:39 PM
[Linked Image]

[Linked Image]
Quote
Here are two pictures of a piece of equipment that came over from another one of our buildings. It's an air dryer for compressed air. As you can see, they didn't want to use fuses, so they came up with a more "practical" idea!!! We had the company photographer take these pictures so we could have this mess documented in case there were any problems with the equipment.
Unreal!!!

I, as well as my co-workers love your forums on code violations. It's unbelievable what some people will do.

-Joe Martell
Posted By: Bjarney Re: No-Blow Fuses - 12/24/03 01:39 AM
Those clips have to be stretched or squeezed...9/16-inch copper tubing doesn't exist.

But, there is a correct product for the job—Bussmann "NTN-R30" for 30A 250V swithces.




[This message has been edited by Bjarney (edited 12-23-2003).]
Posted By: joemar4 Re: No-Blow Fuses - 12/24/03 02:42 AM
Let me make it clear that this is how the equiment came over from one of our other buildings and this is what we found when we came to do the electrical install. This is NOT how we left it. We wanted it documented that the equipment arrived like this, hence we had the company photographer take pictures.
We did the install and corrected any and all pre-existing violations, including changing the disconnect and installing the proper size fuses.
My point was how they could have run this equipment like this in our other building located in New Jersey.
Joe
Posted By: electricman2 Re: No-Blow Fuses - 12/24/03 03:17 AM
I see a red, blue, black and white wire entering the top of the disco, but what appears to be one white wire leaving the short piece of EMT. Am I missing something? [Linked Image]
Posted By: Trumpy Re: No-Blow Fuses - 12/24/03 03:38 AM
electricman2,
That White wire wouldn't be a neutral would it?.
That terminal block at the bottom of the disconnect looks like it's segregated from the metal panel, would this be where the neutral joins with another wire that loops down to the receptacle below?. [Linked Image]
Posted By: Big Jim Re: No-Blow Fuses - 12/24/03 08:07 AM
It looks like kind of a sleazy setup overall but was a fused disconnect required where the equipment was previously installed?
Posted By: pauluk Re: No-Blow Fuses - 12/24/03 04:13 PM
Quote
I see a red, blue, black and white wire entering the top of the disco, but what appears to be one white wire leaving the short piece of EMT. Am I missing something?

Looks to me as though the receptacle below the disco is tapped from the red phase and the main equipment is wired 208V delta with no neutral.
Posted By: mvpmaintman Re: No-Blow Fuses - 12/24/03 11:19 PM
I've seen this done alot out here in the land of OZ. Usually on a roof mounted air handler. Found out that it was a crew run by the guy who is now my boss. He used to do this so that they could keep the units running and find the short when the wire burned up.

BTW, I am looking for other employment.
Posted By: electure Re: No-Blow Fuses - 12/26/03 12:54 PM
Per Paul
>The receptacle below the disco is tapped >from the red phase.
I'd agree, but what's the little box in between the disco and the recp?
Does that contain a 5 amp Edison base fuse for the recp?
Posted By: Bjarney Re: No-Blow Fuses - 12/26/03 08:20 PM
The middle box looks like a Bussmann SOU listed at http://www.bussmann.com/library/bifs/1129.pdf
Posted By: Joe Tedesco Re: No-Blow Fuses - 12/29/03 05:07 PM
Here's a reply I received from Bussmann:

Quote
Hi Joe,

It appears one of the members properly identified the product which we offer.

We offer "dummy" fuses or neutrals for Class H/R, Class CC, midgets (13/32" X 1-1/2") and small dimension (1/4" X 1-1/4") fuses.

These fuses can only be utilized where overcurrent protection is not required by the code, such as for neutrals.

For example, let's say you have a 120/240V system and use a 3 pole 240V switch.

You could run the two hot phases through two of the poles with protection by a fuse and install the "dummy" fuse in one pole, and run the neutral through.

They also use these allot in lighting circuits for the neutral conductor.

Bussmann
Posted By: Joe Tedesco Re: No-Blow Fuses - 12/29/03 05:12 PM
Here are those "Dummy Fuses"

[Linked Image from bussmann.com]
Posted By: ThinkGood Re: No-Blow Fuses - 12/30/03 01:30 AM
So, joemar4, to clarify:

This install did, in fact, require fuses, and somebody (previously) had deliberately eliminated them?

Even if the fuses were not required, obviously copper tubing is not listed for such a use.

Does "dummy" refer to the fuses, or...never mind...

P. S. Under the voltages/amps in this case, would said copper tubing act as a fuse or would it survive a short?

P. P. S. Is the tubing the same as what appears at the bottom-left of the top photo?
Posted By: DougW Re: No-Blow Fuses - 01/04/04 06:28 PM
Obviously, the plumber has been scabbing electrical work again! [Linked Image]
Posted By: ThinkGood Re: No-Blow Fuses - 01/06/04 03:13 AM
DougW:
Quote
Obviously, the plumber has been scabbing electrical work again!

I didn't want to "go there..."

That sure would explain it, though. The fuses blew and the plumber needed to get the thing working again, and...
Posted By: John Steinke Re: No-Blow Fuses - 01/16/04 06:59 PM
I cannot determine if it is required that this disconnect be fused; there may be fuses at the starter.
IF it is not required, then the use of manufactured "blanks" is OK.
© ECN Electrical Forums