Service disconnect breaker question, Siemans.

[andy everett]

I am up-grading my 100A service with a 200A one. My main panel is not near the meter so I have a Siemens 200A service disconnect where the power enters the basement. There are 4 "blades"(right name?) in the disconnect box, two for each hot line. What troubles me is that the 200A Siemens breaker that was sold with the disconnect (looks like four regular breakers tied together so they all switch off at once) makes contact with only two of the four blades, so that all the current must go through only two blades when it seems a better design would be to have all the current go through all four blades, less current per blade.

Do I have any real concerns here, is this a bad design, is this a standard practice?

Thank you for any help.

[David Efflandt]

Did your power company upgrade your service from 100A to 200A and was inside wiring upgraded, or did you just get 200A disconnect and breaker installed on 100A service, in which case using half of it makes sense.

You certainly cannot expect to draw 200A from a 100A supply or output 200A into 100A inside wiring.

[Mark or Sue]

I think I've seen the breakers you refer to at my local hardware store. Seems funky to me too, but I think it is cheaper to gang two 100A breakers together than to make a single

200A one. So in a 200A house service you'd have 4 100A breakers divided into two groups of two paralled breakers. Since this is a factory assembly, it may be that the paralleled breakers have an internal connecting means and just give the appearance of a single bus connection.

If you bought a 200A rated disconnect and it came with this type of breaker, it should work. However, I won't buy equipment using this approach when there are alternatives at similar cost that have a normal looking 200A double pole breaker.

-- Mark Kent, WA