resistance welders

[mo2004]

Hello every body,

Does any body have experience with resistance welder overcurrent protection?

I have read the NEC code 630.31 & 630.32 and I understand it.

But want see how people with experience are dealing with resistor welders. If you can direct me to good internet source to learn more about the subject i would appreciated.

 

[LHarrington]

Good morning,
You need to know what KVA, line voltage and duty cycle your using. For example if you have a 85 KVA transformer on your spotwelder and it's 480 volts the math looks like the following, 85000/480*.70% = 123amp. Size your wire to handle this amperage and then protect the wire. Use class RK1 fuses. Make sure you follow your local requirements as well.

LHarrington

 

[mo2004]

Thank you,

I think this is the case in most cases sense the duty cycle is adjustable and most manufacturers will change the duty cycle.

:smile: :smile: :smile: