I am sure a similar question has already been asked. There is a 208V 3 phase panel, that has a 125amp circuit breaker. It feeds six servo motors 600w each, through their respective amplifiers. The power circuit is 125 amp. breaker - contactor - distribution block - and these amplifiers. Can you give me an idea if this circuit needs to be fixed to comply with code and also protect the branch circuit conductors? PLease let me know about any code reference - NFPA70, NFPA79 etc?
motor branch circuit conductor overcurrent protection
- Thread starter lquadros
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- San Francisco Bay Area, CA, USA
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- Electrical Engineer
A device rated for 600W, fed by a 125A circuit breaker? You need to ask this question?
- Location
- Illinois
- Occupation
- retired electrician
If the installation is covered by the NEC, see 430.52 and 430.53.
motor branch circuit conductor overcurrent protection
Yes. Jraef. I would like to collect all possible results that makes it incorrect. I will examine the code rules stated by don_resqcapt19. I am also trying to understand about the 3 phase noise filter and the servo motors fault current contribution effect in case of a dead short. How badly could the components fail. The total current in the system may be not very high because it is fed from a 480/208 VAC transformer. Nevertheless it would be of importance for us to know this correctly and understand this one better. For now, it is understood by the designer that- " it works and it is a non-issue "
Yes. Jraef. I would like to collect all possible results that makes it incorrect. I will examine the code rules stated by don_resqcapt19. I am also trying to understand about the 3 phase noise filter and the servo motors fault current contribution effect in case of a dead short. How badly could the components fail. The total current in the system may be not very high because it is fed from a 480/208 VAC transformer. Nevertheless it would be of importance for us to know this correctly and understand this one better. For now, it is understood by the designer that- " it works and it is a non-issue "
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