Power plugs

Status
Not open for further replies.

WorkSafe

Senior Member
Location
Moore, OK
I can't find anything, but if I were plugging this welder in hot, I would wear some rated gloves just to be on the safe side. Just my opinion, so I would wait for more feedback.

Does the welder instructions say anything?
 

TxEngr

Senior Member
Location
North Florida
If plugging in hot, you would have a possible arc flash hazard and would be required to wear proper PPE (as determined by the arc flash study) and be trained on the hazards. I suspect that your welders and operators do not have this gear so they should not be plugging in hot. If you have the interlocked welding disconnects that prevent the insertion or removal of plugs while energized, you are assured of a 'dead front' condition and it would then be safe. You then have to train them on the safe operation of the disconnect switches but should not require special PPE other than safety glasses, leather gloves, etc.
 

iwire

Moderator
Staff member
Location
Massachusetts
If plugging in hot, you would have a possible arc flash hazard and would be required to wear proper PPE (as determined by the arc flash study) and be trained on the hazards.

I have never heard of such a thing, can you provide a reference?

I was under the impression that receptacles and plugs have always been designed to be used 'hot'.
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
I have never heard of such a thing, can you provide a reference?

It is referenced in 110.9(B)(4).

110.9(B)(4) Connecting Attachment Plugs

(a) Employees' hands shall not be wet when plugging and unplugging flexible cords and cord-and-plug-connected equipment if energized equipment is involved.

(b) Energized plug and receptacle connections shall be handled only with insulating protective equipment if the condition of the connection could provide a conductive path to the employee's hand (if, for example, a cord connector is wet from being immersed in water).
Says nothing about de-energizing the receptacle.
 

TxEngr

Senior Member
Location
North Florida
Typically, the plugs and receptacles are not designed for breaking full load. To quote from the Appleton website for their Powertite series:
"Circuit Breaking: in 30- through 200-amp units, any arcing created as line
and load terminals disengage is safely confined deep within terminal cavities.
Plugs may be withdrawn in an emergency under full rated loads without
separate disconnect switches"
So they are designed to break under load in an emergency only. Think about the design of the plug where any misalignment could create a problem and the plug not load break rated. I think most would agree that is an arc flash hazard. And this is easily fixed with tools that are readily available out there.

There is a company that makes a load break rated plug and receptacle - Meltric. I've used their products on some motor quick disconnects for skid type equipment where I was concerned a non-electrical type person might unplug the motor. The Meltric switches have contactors built into them that can break the load.
 

dbuckley

Senior Member
Plugs may be withdrawn in an emergency under full rated loads without separate disconnect switches" So they are designed to break under load in an emergency only.
I would read from the use of the term "emergency" in there that they are designed to suffer this level of misuse just once, and then be replaced, unless they have a number in the spec sheet contradicting that.

Personally, am a big fan of having interlocked isolator on any connector over 32A at 400V, though I see un-interlocked (and unswitched, for that matter) 63A 400V connectors all the time...
 
Status
Not open for further replies.
Top