I have a cord connected welder that plugs into a 208/2P receptacle. I am trying to determine the size of the circuit breaker to feed this receptacle, and the size of the receptacle. The welder is rated for 48amps. Should the receptacle be a 250V 50A receptacle? I saw that the OCPD (circuit breaker) can be rated up to 200% higher than 48A but how do I know when to do this, or should I go ahead and use a 100A breaker?
Welding Equipment
- Thread starter lizzie14
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Re: Welding Equipment
You can use a 100 amp circuit breaker but you would need #2 copper wire in cable OR #6 copper wire in conduit most of the way. In the case of #2 copper you would need to reduce the size to #6 before connecting the receptacle.
The wire size also depends on distance. One problem is that when striking an arc the welder can draw 96 amps which would be rather hard on a 50 amp circuit breaker and could slow spot weld the contacts in the circuit breaker. That is, a 50 amp circuit breaker could turn into something that isn't. At longer distances from the power source you need large enough wire to supply that 96 amp peak without excessive voltage drop.
Also, when the arc is steady state you still have occasional peaks currents of twice the average current. If you have too much voltage drop the arc will tend to go out too easily.
In other words, welders draw peak currents that beat up electrical equipment.
You also need to label the receptacle "Welders Only" because of the 100 amp circuit breaker.
And for God's sake, I hope that you are running the branch circuit off of a 150 amp or larger service panel.
You can use a 100 amp circuit breaker but you would need #2 copper wire in cable OR #6 copper wire in conduit most of the way. In the case of #2 copper you would need to reduce the size to #6 before connecting the receptacle.
The wire size also depends on distance. One problem is that when striking an arc the welder can draw 96 amps which would be rather hard on a 50 amp circuit breaker and could slow spot weld the contacts in the circuit breaker. That is, a 50 amp circuit breaker could turn into something that isn't. At longer distances from the power source you need large enough wire to supply that 96 amp peak without excessive voltage drop.
Also, when the arc is steady state you still have occasional peaks currents of twice the average current. If you have too much voltage drop the arc will tend to go out too easily.
In other words, welders draw peak currents that beat up electrical equipment.
You also need to label the receptacle "Welders Only" because of the 100 amp circuit breaker.
And for God's sake, I hope that you are running the branch circuit off of a 150 amp or larger service panel.
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- Massachusetts
Re: Welding Equipment
What?
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