ECN Forum Forums Technical Discussion Electrical Theory and Applications Series Rated Breakers

One more question. If a manufacturer is selling a series rated system, should they indicate where the series rating takes place to accomplish this AIC correction? And what assurance is there that they are providing an integrated and effective system?
Thanks all.

Last leg
I think now that Dave is back on subject the answer lies in his last reply. In Series rating there is NO coordination except accidentally. The right breaker might ultimately trip alone but it is completely possible and part of the design that both the branch and main breakers will trip.
If you want coordinated tripping there are some simpler methods and complex methods to achieve coordination. For me coordination means the O/C device closest to the fault is the only one that trips. It is easiest to achieve in fuses and electronic controlled breakers. Thermal magnetic breakers can be coordinated but as Dave said it is a little less reliable than a more sophisticated electronic trip control breaker.
If the load is really critical don't go for series rated gear.
Coordination is a very complex subject and is an absolute necessity in some factories never mind hospitals data centers, etc.

It is up to the designer, not the manufacturer, to decide when and if series rated equipment is acceptable in their system. For example if selective coordination is absolutely required then I would probably not accept series ratings, however for a general purpose lighting/receptacle panel I would accept them.

Last Leg;

Go to: "http://www.bussmann.com/" and look under their literature and technical information areas for information.

If you like, send me a private email (let me know you are from the ECN forum) and I can email you several files that I have about Series Rating.

Steve