Are fuses and/or breakers still required?

[Ares]

AB makes claim that these combination starters

http://www.ab.com/industrialcontrol...cters_starters/compact_combination/index.html

proviede:
-Suitable as motor disconnect per UL508 and isolator per IEC 947-2
-Short circuit protection per UL508 Type E and IEC 947-4
-Short-circuit rating up to 100 kA
-Provides short-circuit protection with magnetic trip at 13x the maximum current adjustment range.........

Would you agree that for a small control panel with
- 10-12 individual motor circuits say few HP
- and a single main breaker/disconnect - say 200A
no fuses or breaker protection is required for the individual circuits.?

 

[bigamp]

Hello Ares,

Use of these devices as described needs to be in compliance with your local electrical code. If the code allows usage without fuses or breakers then fine.

I would use them without any fuses or breakers in the individual motor 3-phase circuits. You would still need a circuit breaker or fuse for the control circuit. They look to be a good product. I use the equivalent product from Moeller for smaller motors in panel boards just as you describe. I also use them in MCC's sometimes. You can put a whole bunch of them in a tier. Very space efficient and cost effective.

Regards

 

[jbartos]

Suggestion: Please, notice that the starters have protective features integrated; therefore, there is no need for additional external fuses or breakers.
Comment marked ///\\Would you agree that for a small control panel with
- 10-12 individual motor circuits say few HP
- and a single main breaker/disconnect - say 200A
no fuses or breaker protection is required for the individual circuits.?
///Yes, it is possible, if all protective features are embedded in the individual starters. Compare this integrated technology with integrated protective relays that have many ANSI device number functions integrated in one relay, physically. If the protective ANSI device number is not needed, then it is not used; however, it cannot be removed from the product since it is integrated physically.\\\