Non-Seg vs Sandwhich Bus for LV Busway

[mull982]

I have seen a few projects that use LV Busway for the 480V runs between 480V transformer secondary and 480V Switchgear. On some projects I have also seen busway between 480V Switchgear and MCC's.

On some projects I see Non-Segregated Bus Duct and others I see sandwich type Bus Duct. Are there reasons for using one type of bus versus the other in these LV applications? It appears that the Non-Seg Bus Duct is more robust but the sandwich bus may be cheaper and easier to install.

Are there particular reasons for using one type vs the other?

 

[Jraef]

I have seen a few projects that use LV Busway for the 480V runs between 480V transformer secondary and 480V Switchgear. On some projects I have also seen busway between 480V Switchgear and MCC's.

On some projects I see Non-Segregated Bus Duct and others I see sandwich type Bus Duct. Are there reasons for using one type of bus versus the other in these LV applications? It appears that the Non-Seg Bus Duct is more robust but the sandwich bus may be cheaper and easier to install.

Are there particular reasons for using one type vs the other?

Non-Segregated Bus Duct has no phase barriers between the bars. So it's a little trickier to use, but can handle higher temperatures because of better air flow around the bus bars. That's a good thing for applications like connecting a transformer because of the heat put out by a transformer, and the fact that taps off of it are not common and the runs are generally straight into the service equipment. Sandwich bus duct is typically used where you want to make complex bends, lots of tap-offs etc, but the duct is not being used in a high ambient area, such as going from Swgr to MCC

 

[mull982]

Non-Segregated Bus Duct has no phase barriers between the bars. So it's a little trickier to use, but can handle higher temperatures because of better air flow around the bus bars. That's a good thing for applications like connecting a transformer because of the heat put out by a transformer, and the fact that taps off of it are not common and the runs are generally straight into the service equipment. Sandwich bus duct is typically used where you want to make complex bends, lots of tap-offs etc, but the duct is not being used in a high ambient area, such as going from Swgr to MCC

I see a lot of sandwich busduct being used in applications between transformer secondary and LV switchgear. Are you saying that sandwich but may not be the best use in this application because of the heat given off by the transformer? It sounds like Non-Segregated bus should be used for better air flow?

It sounds like Non-Segregated Bus duct is best used for applications that have relatively straight runs and may not be feasible for applications with lots of bends, turns, etc...

I believe sandwich bus has a limitation of 600V which means for MV applications you would need to use Non-Seg? What type of applications call for the use of segregated bus duct?