Odd Electrical Connection 1

[richanton]

I have to hookup a scientific glove box that will be operated with a slightly pressurized nitrogen atmoshpere. The equipment came with an odd electrical penetration consisting of three, bare copper rods that pass through from outside to inside. It is a 208 volt, 1 phase, 90 amp service requirement. Has anyone dealt with trying to make an NEC code compliant electrical installation with anything similar to this.

 

[rbulsara]

Where did this equipment arrived from??

Is this a UL or NRTL listed equipement? A standard product with published specs by the mfr or a contraption put together by "scientists" in the lab? If this is not a standard product of a manufacturer, all bets are off.

Are those rods part of electrical circuit? What does this box supposed to do??

The electrical requirement descibed suggests nothing out of ordinary, but your question is not clear as to what part of Code you are worried about.

 

[richanton]

The glove box is a pressurized chamber with an oven in it. They operate the oven through rubber gloves that protrude from the outside into the environment.

The question is how to connect the bare copper rod(about 1/4" diameter, one per phase) to a standard terminal block so the electricians can terminate the power feeder wire. I was unable to locate any kind of compression type device that would be suitable for sliding over the bare copper conductor.

As an alternate, I tried to not use the provided "electrical" penetration and put a conduit sleeve through the wall and tried to seal it with Duct Seal, but the pressure is escaping so I may have to go back to using the original gas-tight device(the copper rods). I may also try an EYS seal fitting with an expansion Chico compound to get the seal I need around the conductors. If that doesn't work, I"ll have to figure out how to somehow connect the copper rods.

 

[DanDel]

You're certain that the rods are not something like MI cable, where the conductor is encased inside a copper tube with mineral insulation between? (There are fittings for this wiring method.)
Conversely, if they are solid rods, a connection could be made by threading, or drilling and tapping, the rod, depending on it's diameter. I might use a heat-shrink insulation to cover the rest of the rod surface.

 

[ykee]

Why don't you contact the manufacturer and ask them how to hook it up?

 

[ScottyUK]

IP68 cable glands are readily available over here in Europe which would give you a liquid-tight seal intended for immersion: they are good for at least a few meters of water head pressure, i.e. much more than I've ever seen a glovebox running at. I'm sure that there are similar products in the US or wherever you are.


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If we learn from our mistakes I'm getting a great education!

 

[rbulsara]

richanton:

You seem to know very little about what this equipment is yet you figurred that those rods need to be connected one per phase?? How did you reach this conclusion?

There must be terminals provided outside the oven for electrical connection. I do not get as to why you have to penetrate wall, etc.

Ask the manufacturer! At least post a picture of the oven and things you are talking about. Did this unit come with installation instruction?

If not ask the entity who provided it.

 

[edshere]

split bolt, WR crimps????......Need a picture

Ed

 

[waross]

A Burndy KS22 split bolt connector has an opening of 0.26 inches. This or a larger split bolt (also known as a Servit) should do.

http://portal.fciconnect.com/Comergent//fci/drawing/electrical/ks.pdf

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[richanton]

Thanks for all your suggestions. It is helpful.

I attached a photo of the copper bar penetration.

 

[mcgyvr]

You sure those are the electrical connections? From the picture it looks like they are all connected together via the metal cap. I don't see isolation/insulation between each piece of copper.

 

[rbulsara]

richanton:

This obviously is not a standard product, but a cotraption put together by someone. Nor do they look like electrical connection points.

I would stay away from this!

 

[itsmoked]

Yeah, I'm thinking the same thing - stay away.

There are scads of sealing feed-thru s for cables available. I would just get an OffTheSelf unit that works with your oven cable.



Keith Cress
kcress -

http://www.flaminsystems.com

 

[Compositepro]

It sure looks like a gas-tight electrical feed-through to me. But it appears to be an unfinished OEM part and not ready for field wiring. The arangement is similar to a Appleton electrical connector (

http://www.appletonelec.com/ProductsTOC.asp)

The glovebox manufacturer is the one to ask.