Circuit Breaker

[w5rkl]

Afternoon everyone.

I have a circuit breaker question. If a breaker is rated at 240VAC/48VDC at 4 amps what will happen if the breaker is used in a 120VAC circuit and the current exceeds the breaker's tripping current rating? I believe the breaker will trip since breakers trip based on the current flowing through the breaker.

Based on the AC and DC ratings, at 4 amps, I believe the 240AC rating is the maximum safe AC voltage and the 48VDC voltage rating is the maximum DC voltage rating the breaker can handle, both at 4 amps. I also believe the breaker will trip at slightly over 4 amps at 120VAC. Am I correct in my thoughts?

73
Mike
W5RKL

[AB3L]

Mike,
I have a spare Cutler Hammer breaker here for the house panel. It gives the maximum current interrupting rating which is 10,000 amp and that rating is for 120/240 volt.
Your 4 amp rating should be for any of the listed maximum voltages or lower on your breaker.. yes

[w4bfs]

be carefull with this ... some breakers are single acting magnetic while some are compound acting (thermal and magnetic) ... these were developed to handle simple loads  and/or  things like motor starting ... the analogy to electronics is the simple fuse and the time delay fuse ... do the search ...73...JOhn

[w5rkl]

Thanks for the responses.

The circuit breaker in question is a single pole thermal breaker and it's specifications can be seen at the following link;

http://www.schurterinc.com/pdf/english/typ_t9-311.pdf

The breaker is the T9-311C-4. I purchased one from Mouser for a power supply for $1.67. The specs sheet states it is designed for various applications such as power supplies, hand tools, etc. I haven't installed it yet.


73
Mike
W5RKL