Motorized breaker/molded case switch question

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Don Lucas

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Manchester, NH, USA
I am looking for a relatively low cost source of motorized circuit breakers (thermal and magnetic trips) and motorized molded case switches that are suitable for 120V/240V split phase residential use in the USA (either 10 kAIC or 22 kAIC for different geographical regions). I have looked at the Square D PL (PowerLink) QO breakers and they are very cost effective and switch quickly enough (32 ms) for my needs, but are only available in a few sizes and max out at 70A. I am ideally looking for some that can plug or bolt in to a QO type (or equivalent) load center. I am designing a new product line that needs the use of a very specialized load center sized at either 200A or 225A, depending on geographical region. It is different from the usual backup generator type load centers with automatic transfer switches in that it also permits paralleling with the utility and also permits microgrid operation of a whole house with seamless (static) transfers (at least under some conditions) between the utility and one or more renewable energy sources as well as active load management. We plan to design this load center to be compatible with NEC 2014 codes and also with UL 1741 and IEEE 1547 requirements (in particular, IEEE 1547.4, IEEE Guide for Design, Operation, and Integration of Distributed Resource Island Systems with Electric Power Systems).

Can any of you recommend or point me towards specific 200A/225A motorized circuit breaker lines from any of the primary manufacturers that might fit this application? While I would prefer breakers capable of plugging into a QO type panel (or equivalent), I am also open as a fall back position to using DIN rail mounted or even bolted down type form factors and including contactors. The product has to have a relatively low cost - I know that for several thousand dollars each one can obtain almost any type of motorized breaker imaginable, but I need these to have wholesale 1000 piece pricing in the $75 to $300 range, about what I would expect from the Square D QOPL line if it supported 200A ratings. Eventually, I will be speaking to the manufacturers directly, but I could really live without the pressure of a bunch of sales guys at this early stage of the product's development.

Circuit breakers are not my primary knowledge background so any of you that have a lot of circuit breaker experience, I would really appreciate your insight.

Best regards,
Don
 
for a thousand CB order Siemens is almost always the low buck supplier but you have to get past the local supplier. that is sometimes a long and painful process. I don't recall we ever used a motorized one below 1200A or 1600A so no idea of cost for one in a 200A frame.
 
As you have found with the QO breaker, most of the equipment of this type is for lighting or branch circuit energy control. That will keep you in the low amperage breakers.

Anything north of just branch circuit sizes at this point will be pretty costly I would expect.
 
Once you get out of the residential construction type panels, the motor operators, if available at all on 250AF breakers, will be more expensive that the breakers themselves. GE, Siemens and Eaton all make them, because there are ATS manufactures that use them in their ATSs. But it might be that Sq D does not, at least in the Sq. D product line because they don't have an ATS OEM to buy them in enough volume. I'm pretty sure they offer it in the Merlin Gerin product line (the original French part of Groupe Schneider who now owns Sq. D) but the will not likely be listed inside of their Sq. D panel boards.

No matter what though, I doubt any of them will have an option to put motorized mains in a panelboard, the motor operators are too big. You should consider separating the mains from the panel, it's likely your only option.
 
Use a contactor for control, and an MCCB for the protection. Cheaper to use fuses but for the protection but that could be a maintenance nightmare.

I know what your after, as I was looking for something similar a while back and don't think it exists.
 
Thanks for the help, guys! I was beginning to suspect as much. I also checked out some very large appropriately rated rotary switches and found that the motor operator was very expensive and that only a very small number are sold each year. I have started checking in to the other manufacturer's product lines - hopefully, I will find something there. If I find a really appropriate motorized breaker in the right price range, I will post back here to close the loop for future searches.

Best regards,
Don
 
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