Siemens or Square D 400amp Main Disconnect?

[powerplay]

I was curious if there are issues with having an 400amp single phase Siemens Main Disconnect, split to feed a 200Amp Square D panel and a 125Amp Square D panel in a restaurant. The Siemens is 5.5 inches more narrow with the handle infront saving at least 6 inches off the wall I am mounting to, but am I compromising quality?? Like Coke n Pepsi...what's the difference???? The service is coming in on overhead parallel ACWU cables as requested. Thanks again in advance for the excellent feedback!

 

[LarryFine]

Other than making sure you stay within tap rules, and using double lugs, there's no issue.

As for brand, if space is at a premium, go with the narrower one. Otherwise, go by price.

 

[Jraef]

There are design differences in those two specific brands. I would go with the Siemens, it uses double-break contacts as opposed to a hinged switch in the Sq. D. The hinged switch tends to be extra susceptible to corrosion over time.

Full disclosure; I used to work for Siemens but they no longer pay me to care :roll:, but this is my engineer head speaking.

 

[wireguru]

Are series ratings going to be an issue? 400 amp commercial service might have higher than 10ka fault current available....

 

[jim dungar]

Are series ratings going to be an issue? 400 amp commercial service might have higher than 10ka fault current available....

No.

UL listed series ratings using fuses are not manufacturer dependent, unlike with breakers.

And if they were, it would be the fuse not the switch that would matter.

 

[wireguru]

No.

UL listed series ratings using fuses are not manufacturer dependent, unlike with breakers.

And if they were, it would be the fuse not the switch that would matter.

I didnt see the word fuse which led me to believe it was an enclosed circuit breaker... thanks for clearing it up.

 

[jim dungar]

I didnt see the word fuse ....

Either did I.

In my mind "disconnect" means a fusible or non-fusible switch.

 

[Jraef]

Oops... :roll:
My brain fills in details like that without asking... not good.

 

[mull982]

Other than making sure you stay within tap rules, and using double lugs, there's no issue.

For this would you designate one secondary feeder the primary feeder and therefore designate the other one as a tap feeder? Or would they both be considered tapped due to the arrangement?

When you say "double lugs" I assume you are referring to using seperate lugs for each circuit. Is this a code requirement?

 

[kwired]

For this would you designate one secondary feeder the primary feeder and therefore designate the other one as a tap feeder? Or would they both be considered tapped due to the arrangement?

When you say "double lugs" I assume you are referring to using seperate lugs for each circuit. Is this a code requirement?

They are both taps unless a 400 amp conductor is brought to each of the smaller OCPD's then they are feeders.

double lugs are need unless using a lug designed for 2 conductors.