Why is this dangerous?

[Konrad]

After you get done viewing the phone and smacking your forhead, saying, "How dumb can people be??"...

It's in a 1600 amp commercial panel in the basement of a hospital. We're adding on to the hospital, and I found this on Friday. Not in the scope of our work, this was existing conditions found.

The question is: What are the reasons this is so bad? There's more than one thing wrong with foam in this application. I'll explain WHY the owner put foam is in there in a day or two.

There's also a second problem, but it's hard to see in this photo. Extra points if you spot it.

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[Richard Moore]

This is about 1400 amps more than I'm used to.

I'm assuming that is a grounded conductor where the aluminum and copper are incorrectly joined?

As for the foam...I'll guess that the heat dissipation qualities of the conductors are seriously degraded and also that moisture could now collect in the conduit.

[Brian G]

This may not be the bonus, but that split bolt is not an AL/CU rated connector. They make 'em, but that ain't one of 'em. [:-magnify

Brian G.

[Terence McCann]

That is quite unusual to see in a hospital environment (having worked in a few over the years.)

Hospital's are pretty picky about proper work being done.

I sure hope that's a ground conductor and not a hot one! If it were a hot conductor that might explain the funky little green wire trying to hold it off the case as well as the foam backing trying to act as some insulation???? Is the little green wire indicating that it is a ground?? Also the foam has filled the one conduit run coming in from the back of the panel.

The alum/cu connector is incorrect.

The foam inside the panel has been applied at two different times judging from the difference in color between the two.

If the panel is in the basement was there water entering the conduit in the back of the panel and they tried to stop the trickle of water by foaming the inside conduit?

Looking forward to your report!

[Konrad]

Man, I didn't think anyone would see the AL/CU connection, simply because I didn't think it showed up in the photo very well. You guys are eagle-eyed.

The head of maintenance did this to that panel. He was not there at the time I looked at it, so the majority of my history is second-hand..

Yes, there is a conduit (actually two) going out the back of the panel, through the poured foundation wall, and out under the parking lot outside. No one seems to know what they served, they are abandoned. Anyway, during the last rain, they had a lot of water coming through this panel from those two abandoned conduit. This was his (hopefully) temp fix until they find the source of the water infiltration. So there's probably a great big pile of water behind that foam. Great...

On to the foam: Foam is bad because:

1. Yes, heat dissipation is hindered.

2. It is not a UL listed material for this type of electrical application (no elect inspector would approve this condition)

3. Expanding foam is a petroleum based product that is flammable.

4. Expanding foam is a petroleum based product that can corrode the insulation on the conductors.

As for the green 12 ga wire (or whatever it was) I really don't know the history of what/why/how that thing is there. But the ground conductor is as good a guess as I can come up with too.

[Brian G]

Originally posted by Konrad

Man, I didn't think anyone would see the AL/CU connection, simply because I didn't think it showed up in the photo very well. You guys are eagle-eyed.

Hah! Where are my bonus points, Husker Boy? [:-magnify

I have to credit my 6 years of selling wholesale electrical supplies for this one. No one is ever impressed when I tell'em that, but it's been very valuable experience. It helps that I started off sweeping floors & stocking, ended working industrial / commercial / contracting accounts, and did every job in-between.

Brian G.