# Bus Duct Safety...



## Jayc316

The plant I work in uses horizontal, ceiling mounted bus duct for most of the power distribution to feed production equipment. I am looking for opinion, or established policies on the practice of removal and installation of bus duct switches on live bus with running equipment on, lets say a 3 phase, 480V, 800A older ITE bus duct. Any supporting documentation regarding level of PPE, or personal experiences would be greatly appreciated.


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## Jhellwig

Jayc316 said:


> The plant I work in uses horizontal, ceiling mounted bus duct for most of the power distribution to feed production equipment. I am looking for opinion, or established policies on the practice of removal and installation of bus duct switches on live bus with running equipment on, lets say a 3 phase, 480V, 800A older ITE bus duct. Any supporting documentation regarding level of PPE, or personal experiences would be greatly appreciated.


 
The old bulldog/ite bus I would imagine does not have very good arc blast containment to begin with so you would more than likely be dependent on the hazard of the feeder to it. It would be a safe bet to go with the feeder rating as it is a long discontinued style. Siemens doesn't have much info on it and plugs are hard to come by so they might not or not want to give a rating for it. Especially on the stuff that was made before ite bough out bulldog.

Our plant still has some of this bus that is before Bulldog was bought by ITE. It scares the crap out of me pulling some of the plugs out on the bus over the welding areas as they are full of dust and cold probably let loose any minute. I have a little more faith in the Siemens plugs that have the lever but not much.


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## John

i would do a arc flash calulation on it. you can do an "offical" or just a rough calculation. i had a couple thousand feet of old westinghouse 225 amp 208/3 phase and did a guick calculation of it. give it a try by downloading a arc flash cacluator and do the calculations. that you a least know what you are dealing with. then go from there.

http://electrical-engineering-porta...ftware/short-circuit-and-arc-flash-calculator


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## dawgs

We schedule a shutdown and then install the plugs.


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## Jayc316

Jhellwig said:


> The old bulldog/ite bus I would imagine does not have very good arc blast containment to begin with so you would more than likely be dependent on the hazard of the feeder to it. It would be a safe bet to go with the feeder rating as it is a long discontinued style. Siemens doesn't have much info on it and plugs are hard to come by so they might not or not want to give a rating for it. Especially on the stuff that was made before ite bough out bulldog.
> 
> Our plant still has some of this bus that is before Bulldog was bought by ITE. It scares the crap out of me pulling some of the plugs out on the bus over the welding areas as they are full of dust and cold probably let loose any minute. I have a little more faith in the Siemens plugs that have the lever but not much.


So then, the fact would be having live bus "scare the crap out of you" (a group of which I am a charter member) does not inspire you to draw a line in the sand and refuse to remove, or install a switch into a live bus duct? My expectation was that it would be easy to find support for shutting down live bus before working on it but, after considerable internet searching, and a short time reaching out on this site, it appears there is no consensus as to the danger of wrestling with energized bus duct.


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## Big John

Putting in energized bus plugs seems like a pretty plain violation of 130.2(2) in 70E.

This is further supported by table 130.7(C)(15)(a) which considers the task HRC 2 if you know you have <65kA of fault current and an instantaneous trip time.

Honestly, bus plugs are up there with one of the most dangerous tasks I can think of: By design busway needs to be able to supply a lot of energy such that often there is no safe level of PPE for that task. Further, you need to be right on top of the point-of-failure to wrestle a switch in, meaning you're taking the full brunt if it goes south.

At the very least you need an arc flash calculation to determine what PPE you must wear.


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## macmikeman

Mikey no likey......:no:


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## Jhellwig

Jayc316 said:


> So then, the fact would be having live bus "scare the crap out of you" (a group of which I am a charter member) does not inspire you to draw a line in the sand and refuse to remove, or install a switch into a live bus duct? My expectation was that it would be easy to find support for shutting down live bus before working on it but, after considerable internet searching, and a short time reaching out on this site, it appears there is no consensus as to the danger of wrestling with energized bus duct.


It is a risk that I have somehow convinced myself is acceptable even though I know better. I don't like it but throwing the safety card around here gets you unemployed. Sleeping well at night and feeding you family are often mutually exclusive. We do what we can to mitigate the hazard but it never goes away.


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## John

the OP may have to change his shorts if he does a arc flash calculation. Installing a buss tap, like others have said is high on my list of things i really don't want to do. the older the equipment the greater probably that something could go wrong. 
Does anybody have information about newer busduct tap installation instructions or manufacturers recommended procedures?


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## LuckyLuke

Used to work on those years ago for a couple customers. We always turn them off when installing or removing switches. We no longer get work there due to them finding someone that would work on them live with no questions asked. 

One of the issues with those older buss ducts is I have seen missing hardware all along them, that is just the start of asking for trouble.


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## Moonshot180

Brings back a not so good memory of a time when I was an apprentice, and the Journeyman I was working with was trying to get a disco' to plug in on a live bus duct.

Guy was wearing a tank top and shorts, on top of a single buck scaffold.

I remeber him cussing at it, while he was banging, pushing etc...on the disco to get it to snap/plug in.

That whole run of LIVE buss duct was shaking and moving around.

I asked him if he should stop, and I was cussed at also..so nothing I could do then but watch and just hope nothing bad happened.

Some people are just dangerous to be around


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## Southeast Power

Jayc316 said:


> The plant I work in uses horizontal, ceiling mounted bus duct for most of the power distribution to feed production equipment. I am looking for opinion, or established policies on the practice of removal and installation of bus duct switches on live bus with running equipment on, lets say a 3 phase, 480V, 800A older ITE bus duct. Any supporting documentation regarding level of PPE, or personal experiences would be greatly appreciated.


Understand that if anywhere along that bus duct, anywhere, there is a spot ready to go, it's going to happen when you are pushing hard against the bus bars trying to plug in a tap.
Copper will just explode and Tripp the breaker.
Aluminum, to some extent will explode and then melt. 
Either way, the very low frequency of installing a bus plug that might take 20 minutes compared to the risk of loosing some plant critical distribution for a day or so should be a no-brainier to whoever is in charge of that facility.


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## Michigan Master

We used to install/remove bus plugs live all the time a _long_ time ago; however, with adoption of NFPA-70E into our Electrical Safety Procedure (ESP) all that changed. 

We define this task as live work and therefore require an Energized Electrical Work Permit (EEWP) and in most cases the task does not meet the justification for live work outlined in OSHA 1910.333(a)(1).

Also if you read and follow the manufacturer's instructions (screen shot below), they often say to de-energize the busway first.

I work in an automotive manufacturing plant, and at first everyone said there's no way we can shutdown an entire busway every time we need to install/remove a bus plug (which is fairly frequent). However, the task really doesn't take that long if you have everything prepared a head of time. We plan ahead and schedule a short outage for lunch time or shift changes with minimal impact to production.


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## just the cowboy

*Yes back then, no now!*

When I think of how we plugged them in 25 years ago, I think WOW. 
It was common practice to start it in then press it in by pushing it in with shoulder or chest while pulling on buss.

Young and stupid then, not now.


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## jbfan

It has been some years since I had to install a buss plug, but I hate the thought of having to re-energize the 40 year old switch gear also.


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## Zog

And make sure to megger the plug before installing


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## Jayc316

Thanks Michigan Master

That is just the type of information that I was hoping to get.


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## freeagnt54

If they can't afford to shut it down for 2 hours then they sure as hell can't afford to have it shut down for weeks if it blows.


We recently lost a customer to another contractor because we refused to do energized work on their 480v gear. A few months later the other contractor blew some gear up and now we're back there picking up were they left off.


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## Southeast Power

I remember going to the hospital back in the late 60s early70s to see my dad after a bus duct exploded on him.
I'm have to find the pic and post it.


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## Jayc316

jrannis said:


> I remember going to the hospital back in the late 60s early70s to see my dad after a bus duct exploded on him.
> I'm have to find the pic and post it.


As hard as that information may be to see, it may be just what this group needs to be exposed to, to understand more clearly the consequences of the situations we are put in everyday.

"Work Safe"


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## Bad Electrician

We do quite a bit of busway work and I have been on a fair number of blow ups from electricians installing busway plugs while the busway is energized, one fatality and several severe burns.

NO HOW NO WAY, would I do it.


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## Southeast Power

I really don't know how many I've plugged in hot but, now, safety is paramount. Is considered reckless and foolish to plug them in hot now a days.
I might be that the older bus duct just looks like it wants to blow up and the new bus duct looks so cheaply made that it's going to blow up.
Or
Maybe I'm older and have seen some bad stuff that I won't have time enough to recover from.


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