Cold Fusion
Senior Member
- Location
- way north
I agree with that.
I'm thinking there is no motor to protect - it has failed.
However, if the motor fails, then the CB should trip inside of the conductor thermal limit - protecting the conductors.
cf
Nec
- Thread starter 68electro
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However, if the motor fails, then the CB should trip inside of the conductor thermal limit - protecting the conductors.
cf
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I agree that most times if a motor experiences some kind of short it has failed and no CB trip will do anything to prevent the short, but it could well prevent additional damage to the motor.
cschmid
Senior Member
- Location
- Northern cold country
still interesting because we understand what we are trying to protect when we design but the code does not specifically state what it is..Atleast I do not know of any where it specifically states it. It does give info on how to protect overloaded and short circuits but does not say we are protecting structure, wire, loads, ect..
You are limiting yourself to the concept that there is only a motor inside that device. Other components may be damaged if the motor is allowed to "burn out". Limiting the heat generated by failure may well protect all the control circuits. It may also prevent the plastic case on your vacuum cleaner from melting or burning. Therefore the equipment being protected is not necessarily the component that failed.
volt101
Senior Member
- Location
- New Hampshire
As far as heat sinking is concerned, some would argue that the wire protects the breaker.
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