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What is actually consider a Bus or Busway

New postPosted: Thu Aug 25, 2016 9:41 am
by JohnSTI
In trying to interpret the understanding of using Flex Cord drops I continually run across the term 'Bus" or Busway". My understanding of these terms are to be related with "multiples" runs within a group such as in a tray (open or closed) not an individual run.
for example;
Branches from busways shall be permitted to be made in accordance with 368.56(A),(B),and(C).
and
368.56(B)(2) notes that for industrial installations with qualified personnel, it is permitted to install a flexible cable drop that is connected without an attachment plug, with no length limitation from the busway plug-in device to the tension take-up support, provided the cable is supported at intervals not exceeding 8 ft.

What I'm trying to resolve is I have a circuit coming from a Main Panel box the is in metal conduit, running up and across the ceiling stops over a machine where it ends with a square electrical box or gang box if you will. Then a Flex cord drops down to the machine and the machine plugs into the drop end.

My question is... "Is the span of conduit along with the electrical box considered a "Bus" or "Busway""? So that I know to apply any mentioned "Bus" or "Busway" requirements in the code to these components.


Thanks guys

Re: What is actually consider a Bus or Busway

New postPosted: Thu Aug 25, 2016 3:54 pm
by Jerry Peck - Codeman
JohnSTI wrote:In trying to interpret the understanding of using Flex Cord drops I continually run across the term 'Bus" or Busway". My understanding of these terms are to be related with "multiples" runs within a group such as in a tray (open or closed) not an individual run.


First, let's define what a bus is and what a busway is:
- a bus is typically a length of uninsulated or insulated, copper, aluminum, or brass metal bars, rods, or tubes.
- a busway is:
- - From the 2014 NEC - 368.2 Busway. A raceway consisting of a grounded metal enclosure containing factory-mounted bare or insulated conductors, which are usually copper or aluminum bars, rods, or tubes.

What I'm trying to resolve is I have a circuit coming from a Main Panel box ...


Let's clarify that "main panel" term - is that the "service equipment panel" or is that a downstream panel (not 'service equipment')?

Many people use the terms "main panel" and "sub panel" yet do not always mean the same thing. A "service equipment" panel has the neutral bonded to ground, other panels have the neutral isolated from ground.

Once we are past the 'where the neutral is bonded to ground' panel, all panels are the same.

Getting back to your question of having a circuit coming out of a panel:
in metal conduit, running up and across the ceiling stops over a machine where it ends with a square electrical box or gang box if you will. Then a Flex cord drops down to the machine and the machine plugs into the drop end.


and

My question is... "Is the span of conduit along with the electrical box considered a "Bus" or "Busway""? So that I know to apply any mentioned "Bus" or "Busway" requirements in the code to these components.


No, that conduit is not a busway and does not contain bus sections. The requirements for bus and busways, and the permitted wiring methods for same, do not apply to the circuit in your description.