Maintenance of Your Bus Duct Distribution System
Square D Bus Plug
It is always a good idea to de-energize bus duct before you install or remove a bus plug. If the plug is heavy it can be difficult to engage or disengage across all three phases at the same time. The result is you could partially engage one or more of the phases and twist or bend the connection point. This could result in subsequent hot spots which could lead to failure.
You also have to consider that this failure would occur on the line side of the bus plug where the current and hazards are much greater rather than the load side, where the amperage would be much lower. Want easy proof? Consider 200 amp bus duct with ten, 30 amp bus plugs (each fused at 20 amps). The problem on the line side of any one of the ten, 30 amp bus plugs is really a problem on a 200 amp piece of equipment. The same goes for removing a plug with the bus hot. The plug may be dirty or greasy and harder to control as you try to close it in or withdraw it from energized bus. Better to move the plug with the bus turned off.
Is plugging in a Bus plug to a live bus duct consider Live Work by OSHA does it violate the OSHA standard??
@Bryan
We do not know of OSHA specific text that says plugging a bus plug into a live bus duct is live work or not live work. We would be surprised if OSHA would be that specific. We do know that OSHA CFR 29, Part 1910.309 through 1910.330 mandates “Safety–Related Work Practices” … “be employed to prevent electrical shock or other injuries resulting from either direct or indirect electrical contacts, when work is performed near or on equipment or circuits which are or may be energized.” The danger of shock or arc blast hazards must be reduced to a safe level such that the person would not be seriously injured or killed… as per OSHA’s General Duty Clause. MIDWEST believes removing and installing a bus plug on an energized bus duct, even if it is classified as not “Hot Work,” is not safe. MIDWEST recommends de-energizing the bus. Because of the actual physical work required to remove or install a bus plug in a live bus duct, there is an extreme arc burn hazard.
when installing electrical circuits using bus duct, is it necessary to use a bus plug circuit breaker and a circuit breaker or disconnect at the equipment location? is there code that covers this?
is there a requirement as to hook sticks.
where they are located.