Code Quiz

Status
Not open for further replies.
B

blacy

Member
I am an electrical engineer working on justifying the replacement of some old electrical distribution equipment. I have found several code violations, but there are other issues here that don't "seem" right, but I can't pinpoint any specific violation.

Here's the scenario (and some pictures too)...

The main disconnect inside this particular buidling is being fed from a the main switchgear (a 600A fusible disconnect) underground with 600mcm (I think - the markings are gone) wire. The main is a fusible disconnect, fused at 400A - one of the three fuses is a renewable fuse. (By the way, this is a 480V system).

So far, so good. Then there are 8 taps off the main disconnect. There are 4 main lugs attached to the disconnect and an "extra" lug drilled above the main ones. The lug on the right rear is a 4/0 wire that is spliced in the cable tray to a #12, #2, #4, and 3/0 wires (big ugly bundle). The #12 feeds a motor circuit about 50 feet away. The others feed other panels on this same wall.

The lug on the right front and left rear each feed a 125A disconnect (2/0) wire) about 15 feet away. These disconnects each feed a 75HP Air compressor.

The lug on the left front feeds another 125A disconnect with 3/0 wire which in turn feeds two 30A disconnects with #6 wire. This same lug has 5 - #10 wires connected under the same screw. Two of these #10 wires (parallel feed) feed a 480V outlet about 50 feet away. Another two of the #10 wires feeds a 20A disconnect to a small heater. The fifth #10 wire feeds a 30A disconnect that in turn feeds 5 small motors (1HP).

The added lug is a #6 wire that feeds (daisy chained) two 15kVA transformers, which each feed a 125A, 120V lighting Panel.

One more detail. The main disconnect cannot be completely closed, so the dust in the factory completely covers the wires in the enclosure.

I've found violations in 240.21, 310.4 and 240.4. Thanks for your help.

Barbara
 
Since I'm being lazy today and don't really feel looking into it to much, I'm not going to give you an answer, but I will say that those pics look like and arc fault waiting to happen.
 
cowboyjwc said:
, but I will say that those pics look like and arc fault waiting to happen.
Click to expand...

My non-lazy answer is REPLACEMENT no matter what the violations. A disaster looking for a place to happen.
 
What do they make there "crud for electrical equipment" ? Maybe they should consider dust proof enclosures as part of the upgrade.
 
The factory makes mineral wool insulation. It's an old plant and I'm working on updating one area at a time. I want to get this done right (replace the whole thing), but I need sufficient justification. I don't want to ask for the money and have the management throw a little money just to eliminate the tap issue.

Can anyone tell me where in the code it is forbidden to add the extra lug. Common sense tells me that's a no-no, but I haven't been able to find any language to that effect in the code.

Thanks for 110.12 - that will ensure that I can replace the enclosure.

Believe it or not, I'm in the process of replacing the panels in another area that were far worse than this one. :D

Barbara
 
I would think while you are waiting for an approval to upgrade this mess you may want to shut down power and clean out the dust as a short term safety precaution.
 
blacy said:
The factory makes mineral wool insulation. It's an old plant and I'm working on updating one area at a time. I want to get this done right (replace the whole thing), but I need sufficient justification. I don't want to ask for the money and have the management throw a little money just to eliminate the tap issue.

Can anyone tell me where in the code it is forbidden to add the extra lug. Common sense tells me that's a no-no, but I haven't been able to find any language to that effect in the code.

Thanks for 110.12 - that will ensure that I can replace the enclosure.

Believe it or not, I'm in the process of replacing the panels in another area that were far worse than this one. :D

Barbara
Click to expand...

If your are replacing all of the electrical equipment you might want to consider building an electric closet big enough to house the new gear plus room for future and make that room dust proof and totally eliminate the problems that you have now.
 
We make a "fire-resistant" insulation for steel. Definitely not flamable. It melts at about 2500degF.

Barbara
 
Status
Not open for further replies.
Top