Fire Stopping Buss Duct

[mahobbs]

I work in a Hospital that was built in 1964. The main power risers to each floor distribution panel are feed by way of a Westinghouse 480VAC 2000Amp bus duct.
We were written up by the joint commission inspection because there is no fire stopping in-between the 4 buss bars, inside the buss duct.
I told them that you don't put anything between the buss bars. They told me to show then something in writing that will say that buss bars in a buss duct don't need or can't be fire stooped.
Can any of you help me

 

[ralpha494]

Re: Fire Stopping Buss Duct

I just attended a firestopping seminar two weeks ago put on by a firestopping contractor in Milwaukee, WI.
From his business card:
www.firestopstandard.com is the web site.
or direct e-mail gary@hamiltonbenchmark.com
or toll free 877.313.3103
Please post the right answer. I would bet you don't stick anything in the bus duct, but I don't know the insulation value of the firestop material.

 

[iwire]

Re: Fire Stopping Buss Duct

Just a wild guess but I would think you would have to buy a section of fire stopped bus duct from the manufacturer or use some sort of kit supplied by the manufacturer.

I can not imagine just stuffing rock wool or Intumescent fire stop into a bus duct.

The installations I have been involved with had fire stopping on the outside of the duct only.

 

[realolman]

Re: Fire Stopping Buss Duct

How'd they figure that out?

Must have been a thorough inspection.

Is Westinghouse still in business?

[ February 14, 2006, 05:28 PM: Message edited by: realolman ]

 

[roger]

Re: Fire Stopping Buss Duct

Originally posted by realolman:

Is Westinghouse still in business?

It is now Cuttler Hammer

Roger

 

[MJJBEE]

Re: Fire Stopping Buss Duct

Originally posted by roger:

Originally posted by realolman:

Is Westinghouse still in business?

It is now Cuttler Hammer

Roger

I thought that it depended on what you wanted to buy.

 

[roger]

Re: Fire Stopping Buss Duct

Originally posted by MJJBEE:

I thought that it depended on what you wanted to buy.

In what way?

Roger

 

[ralpha494]

Re: Fire Stopping Buss Duct

If it's a nuclear power plant, Toshiba just bought out Westinghouse for 5.2 billion.

 

[realolman]

Re: Fire Stopping Buss Duct

I know ABB ( or some such from Sweden ) bought some of their transformer business and I think they went down the tubes.

I haven't seen any Westinghouse anything for years. (maybe dishwashers or something )

 

[charlie tuna]

Re: Fire Stopping Buss Duct

bus duct has been around longer than many of the present fire rating laws and regulations. the local inspection departments in this area approved installing galvanized sleeves packed with mineral wool -- like a floor sleeve would extend 12 inches above and below the floor slab and then packed with mineral wool -- the bus was still open inside -- that was it's original design. the intent was to contain the fire on the floor of insidence.

westinghouse switchgear is out of business... now, cutler hammer makes equipment that is compatible with westinghouse switchgear. i had a westinghouse 400 amp fused disconnect fail on an emergency feeder to a transfer switch. i had no choice but to replace it with a cutler hammer -- and the bolt holes matched up and the entire assembly was the same as the westinghouse except the name was cutler hammer. the ahj wanted a letter from westinghouse ---there was no westinghouse switchgear division to get a letter from!!! first i had to get a letter from my supplier that westinghouse was no longer available. finally, he accepted a letter from cutler hammer that indicated they were compatible....

 

[sandsnow]

Re: Fire Stopping Buss Duct

Those guys have a little info and are running with it.

I wonder what other "codes" they are enforcing.

I suppose they want firestopping on the inside of the conduits in between the conductors also.

I dont know what building code you're on. Here, it's the '97 UBC.

It is impossible to install buss duct through floors in a building where the floors have a 1 or 2 hour fire resistive rating. And comply with the building code. Barring any new wave systems that insulate the duct above the floor.

The through penetration firestop system for a buss duct needs a T-Rating equal to the fire resistive rating of the floor. There are not any systems that will give you a one hour or better T-Rating. Fifteen minutes, thirty tops; it's been a while since I've looked them up.

To obtain a T-Rating:
A mock up of the floor is made
Penetrating item is installed and firestop system installed.
A thermocouple is placed on the non-fire side at a standard distance above the "floor"
Flame On
As soon as the thermocouple reaches a standard temperature, the T-rating (elapsed time it took) is established.

So big metal buss duct with flames shooting at it. Metal conducts heat. You think maybe it's going to get kind of hot above the floor??? You bet it is!!!

Oh BTW, thanks for the laugh!!! I can't to share this one at work!!!!

 

[LawnGuyLandSparky]

Re: Fire Stopping Buss Duct

What's next, firestopping inside chimneys?

 

[charlie tuna]

Re: Fire Stopping Buss Duct

bus duct is one electrical system that usually does not contain it's failure within itself. the older bus duct is basically open wiring! but the new bus is enclosed with little open space for smoke and flame to travel between floors during a fire. i have seen where a bus duct caused fires during it's failure. once it failed over a lamp storage area that started all the lamp boxes on fire --- and the other time the building allowed a tenant to store some files in an electric room that the bus ran through!!! the new stuff is sealed up pretty good!!!

 

[Zifkwong]

When I worked at a utilitity we would firestop all of our transformer bus duct with an epoxy/glass bead combination. This bus duct normally operated at 28 or 13 kv.