It is currently Sun May 28, 2023 3:48 pm

Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: Opening Door on Breaker Compartment
PostPosted: Wed Oct 13, 2010 5:38 am 
Plasma Level
User avatar

Joined: Wed May 07, 2008 5:00 pm
Posts: 879
Location: Rutland, VT
In a previous thread, "Flash, Flash Boundaries", there was a comment on is opening a door considered "interacting" with the equipment and is AF PPE required? In the particular context, this was for a medium voltage, GE MagnaBlast (gotta love the name in this arc flash arena), whether opening a door with the breaker opened, racked down and shutters closed required PPE. It may useful for a discussion on this point.

Now, playing devils advocate for discussion purposes, why would open the door, in this case be considered interacting with a piece of equipment? How could the door cause an arc flash event?

Barry Donovan, P.E.

 Profile Send private message  
Reply with quote  
 Post subject:
PostPosted: Wed Oct 13, 2010 5:57 am 
Plasma Level

Joined: Mon Jun 02, 2008 11:58 am
Posts: 1103
Location: Charlotte, NC
Here are my thoughts on this:

Some breakers have a "door interlock", which trips the breaker when you open the door. Late 70's early 80's vintage Westinghouse gear for example, I always thought it was one of the dumbest design ideas ever but they are out there, and without being equipment specific 70E needs to cover thier bases.

On MV gear with electro-mechanical relays a mechanical shock can cause the relays to trip the breaker.

Older breakers can also have exposed energized parts when you open the doors.

Improper trip latch adjustments can have some breakers mechs just a hair away from tripping, the slightest vibration can cause a trip.

These may be some of the reasons behind the thinking of the commitee. Do I feel comfortable opening a door without PPE? Sure I do, maybe stupid on my part but I know what to look for, but the way I interpret the 70E is PPE is required (As you explained in your post).

 Profile Send private message  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC - 7 hours

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
© 2022 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883