# Bus Plug Safety



## Almost Retired (Sep 14, 2021)

there are many plug and receptacle combinations that include a disconnect mechanism that activates before removal and after insertion of the cord cap


----------



## SWDweller (Dec 9, 2020)

Answering your question in general terms provides you no real answers. Since we do not know the condition we could only answer in general.

What does you HR/Safety department say. Really does not matter what you say. Are you governed by any statues? 

If the buss duct does not have the easy in and out feature then I would not do it hot.

Has your plant had an insurance audit in the last 12 months? Have they done an Arc Fault Study? Are the values posted at the location. 
What safety gear does you work place furnish you? Do you have a blast suit?


----------



## Jomoma (10 mo ago)

SWDweller said:


> Answering your question in general terms provides you no real answers. Since we do not know the condition we could only answer in general.
> 
> What does you HR/Safety department say. Really does not matter what you say. Are you governed by any statues?
> 
> ...


In this particular case, we are pulling out one machine and replacing it with a different one, the configuration is different so we need to redo the conduit from the existing bus plug to the machine location, we will not be removing the plug, just the load side wiring.
We need someone to go up in an aerial lift and pull the wires off of the load side of the bus plug and then reconnect wires after rerouting the conduit. This would be done with the bus plug disconnect turned off of course.
We do arc flash here and have everything up to and including a 40cal suit.
The 480v bus arc rating is 42" limited approach, 12" restricted and 1" prohibited.


----------



## Almost Retired (Sep 14, 2021)

if you have a disconnect after the buss plug, i dont understand what the problem is ...
unless it is the buss plug disconnect being up in the air on the buss
if it is not feasible to move that disco down to the floor (because of machine configurations and placements changing)
then i dont know of a better system than you have
_as long as you install ground level disco's near the machine_ each time you place a new machine
then i dont know of a code reference that would prohibit that scenario


----------



## Jomoma (10 mo ago)

Almost Retired said:


> if you have a disconnect after the buss plug, i dont understand what the problem is ...
> unless it is the buss plug disconnect being up in the air on the buss
> if it is not feasible to move that disco down to the floor (because of machine configurations and placements changing)
> then i dont know of a better system than you have
> ...


The job requires that we replace the wires and conduit from the plug to the floor level disconnect.
In order to remove and replace the wiring from the bus plug disconnect, you have to work inside of the bus plug (still hot on the line side) which will have exposed live terminals at <12" from the work being performed.


----------



## Almost Retired (Sep 14, 2021)

Jomoma said:


> The job requires that we replace the wires and conduit from the plug to the floor level disconnect.
> In order to remove and replace the wiring from the bus plug disconnect, you have to work inside of the bus plug (still hot on the line side) which will have exposed live terminals at <12" from the work being performed.


maybe set a junction box below the disconnect with a terminal strip?
both sides dead, easy peasy wire change outs, no taping required
keep various size spare adapters inside the jbox for different sizes of conduit when changing it


----------

