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mstrlucky74

Senior Member
Location
NJ
I know you can “cowboy” anything but is it safe/practical to terminate feeders on this extg. switch while the board is live? Thanks.
 

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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I know you can “cowboy” anything but is it safe/practical to terminate feeders on this extg. switch while the board is live? Thanks.

You might be able to come up with a "safe" way to do it.

You might even be able to come up with an OSHA legit justification for doing so.

My best guess though is there is no OSHA legit way to do what you want to do and it probably would not be all that safe anyway.
 

cuba_pete

Senior Member
Location
Washington State
the amount of fault current is not what matters.

Yeah, I get the voltage...208 is not allowed where I am, anyway. Off the cuff, looking at that section, I wouldn't want 800A of just about anything flowing through me if I was part of the fault path i.e., ungrounded conductor to ground.

That cooks your hot dogs just a wee bit faster.

800A exceeds my SCCR.

So, you go ahead...I got your back.
 

kingpb

Senior Member
Location
SE USA as far as you can go
Occupation
Engineer, Registered
is it safe/practical to terminate feeders on this extg. switch while the board is live? Thanks.

Yes, with the switch open, you can terminate on the load side of the fuses. You need to do a hazard assessment including an arc flash analysis and determine what PPE and other protective equipment you will need, provide training on use of PPE, and go over how the work will be performed.

or,

Just don't work hot.
 

lielec11

Senior Member
Location
Charlotte, NC
Yes, with the switch open, you can terminate on the load side of the fuses. You need to do a hazard assessment including an arc flash analysis and determine what PPE and other protective equipment you will need, provide training on use of PPE, and go over how the work will be performed.

or,

Just don't work hot.

Agreed as long as all safety precautions are taken I don't see why you can't open the switch and terminate on the load side of the lugs with the switch dead. I understand some may not like doing that but I've seen it done in the field countless times safely.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Agreed as long as all safety precautions are taken I don't see why you can't open the switch and terminate on the load side of the lugs with the switch dead. I understand some may not like doing that but I've seen it done in the field countless times safely.

"Safely" and "without getting killed" are not the same thing. :D
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Well that depends partially on the person performing the work ;-)
I beg to differ. Yes, the thing you are touching is not energized. But you are only a sneeze, or a slip of the tool, or a leg cramp, or one of a million other possibilities away from losing just a bit of your balance, resulting in contact with a live part. In that sense, it is not safe, even if it never happened to you.
"An accident waiting for a place to happen will, given time, find that place." {Famous words from some famous person.}

 

kingpb

Senior Member
Location
SE USA as far as you can go
Occupation
Engineer, Registered
"Safely" and "without getting killed" are not the same thing. :D

The proper PPE is supposed to limit the injuries (not prevent) to those that are recoverable. To me, still not a risk worth taking; and no electrical system continuity or companies profit is worth the potential loss of someone's livelihood.

The profit will all be gone once the lawyers get done, and no judge is going to side with the company even if every precaution possible was taken.

My motto; never work hot, never pay for arc flash analysis.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Yes, with the switch open, you can terminate on the load side of the fuses. You need to do a hazard assessment including an arc flash analysis and determine what PPE and other protective equipment you will need, provide training on use of PPE, and go over how the work will be performed.

or,

Just don't work hot.

as long as there is no exposure to energized parts it is acceptable. if there is exposure to energized parts it is probably forbidden. it is hard to know just what exposure he might have in this case.
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
IMHO this all depends upon the design of the switch, and therefore all comes down to money.

In _theory_ the switch and board could be designed so that the feeder could be terminated with no exposure to live parts. Lock out the switch, no exposure, and you are not working hot.

But such a switch and board would be more expensive than one where the parts are exposed.

The company doesn't want the expense of a shut-down, and they don't want the expense of systems that can be terminated without exposure to live parts. They want you to risk your life to save them a few $$.

Hell, these days you can probably get a robot capable of doing the termination. $$$ again.

-Jon
 

Tony S

Senior Member
When I started in this trade boards like this were common place. You just got used to working on them live but you couldn’t be complacent otherwise they would bite you.

TRK-2-switch_zps90a2a75e.jpg

Obviously they had to go.

The new distribution gear was in the main GE System4 or Miniform for smaller loads. Supposedly the company didn’t approve of live working. Its strange how I would be asked when working a night shift if I could add another 630A feeder to a main board. Possibly something to do with the health and safety guys didn’t work nights.

http://www.scatco.co.uk/system4
http://www.scatco.co.uk/miniform
 

rambojoe

Senior Member
Location
phoenix az
Occupation
Wireman
worker safety aside...the problem with hot work is when something does go wrong the equipment will be down for MUCH longer when you find yourself jumping in the truck and driving to the next state to get the destroyed parts !
 
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