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Hackenschmidt
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How did you determine a 200A breaker for that machine?
 

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Marine
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This welder has 3/0 copper and a 200amp single phase 208v breaker.

When in operations the wires slap in the conduit as well as lighting flickers a bit... any ideas as to what could be the cause of this as well as a possible resolution?

I am planning on moving lighting to a phase not used by this machine. Hopefully that resolves the issue..

In my experience the wires jumping in the conduit signifies too small of conductors?

Thanks
The wires are moving because of the amount of current flowing. Wires carrying current in opposite directions will push themselves apart. If anything, larger conductors will allow more current to flow.

Bus bars can be bent if enough current flows during a fault. That's why cables should be lashed inside gear.

Line Font Parallel Auto part Aviation
 

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Hackenschmidt
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To me it seems like with it being 1phase it has to be a ground fault becuase the vibration of the wire in conduit is caused by lenz law basically 2 magnets pushing against each other and the only way to have that on 1 phase would be ground fault. Be it in your wiring or the machine. Could be I squared r loss too and that’s amplified by being undervolted increasing the resistance
I am not sure about that, if the current on the two wires is in opposite directions, they push apart, right? The two phase conductors are 120* apart but the current in the conductors is still equal and opposite at any time, the magnitude of the current is still alternating on a sine wave.
 

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Ready Mix concrete plant electrician
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I am not sure about that, if the current on the two wires is in opposite directions, they push apart, right? The two phase conductors are 120* apart but the current in the conductors is still equal and opposite at any time, the magnitude of the current is still alternating on a sine wave.
You’re right, when current flows through a conductor, it’s a magnet. When it’s on AC current it’s going to move around and rattle in a conduit that’s not full.

Watch loosely coiled welding leads hanging while someone is stick welding with a high current. They jump and move quite a bit.
 

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Commercial/Industrial and Service work
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I am not sure about that, if the current on the two wires is in opposite directions, they push apart, right? The two phase conductors are 120* apart but the current in the conductors is still equal and opposite at any time, the magnitude of the current is still alternating on a sine wave.
That’s right I forgot he feed it with 208 sp so they are 120degrees I stand corrected
 

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I can't believe nobody has pointed out the obvious solution. Wires jumping around in the conduit just means the conduit is too big. Smaller conduit = no room for the wire to move. Simple ;)

Seriously though. Isn't a spot welder basically a fault by design?
 

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I can't believe nobody has pointed out the obvious solution. Wires jumping around in the conduit just means the conduit is too big. Smaller conduit = no room for the wire to move. Simple ;)

Seriously though. Isn't a spot welder basically a fault by design?

NAILED IT !!
 

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When I used to do a lot of primary injection you could get the cables to push each other apart a good foot, foot and a half.

When we were maxed out on current on a particular setup, twisting the cables would sometimes give us that little bit of extra current to hit the pickup we were shooting for.
 
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