Correct selection of switch

[ankanphukan]

Hello Everyone,

Please help me figure out this basic concept. It is vey silly though, I am quite confused.

I have a 50Ah battery pack, with a peak current of 150A. It is connected to a 3kW motor. The controller maximum current rating is of 200A. I wanted to connect a switch in between the battery pack and the motor controller.

My question here is, can I use a switch of 63A switch in between the battery pack and the motor controller? What can be the consequences? Kindly suggest any effective alternative to this solution.

Please help me !!

Thank you for your time and consideration.

 

[amberwolf]

The switch needs to be rated for the full maximum current it will ever see in use. If it is not it may heat up and the contacts (and housing, etc) may be damaged from heat generated by current higher than it was intended for.

It also should be rated for the maximum voltage it will ever see, or else if it is ever switched off under any load it could continue arcing across the contacts just like a welder, whcih gets very hot very fast and can lead to a fire (and will damage the switch even if no fire).

If the switch you're going to use is a circuit breaker, it is even more important for it to be correctly rated, which means it must be rated for *more* than the maximum current. Each breaker model should have a chart from it's manufacturer for how long it will take to break the circuit under specific load conditions, so you'd need to refer to that info to pick the right breaker for your usage.