2 phase weilder

[gjcone44]

been asked the question, why is only one of his three phase meters, spinning faster, when the weilder is used, when it has a 2 phase supply?

 

[pmac10]

never heard of or used a 2 phase welder, but to hazard a guess, perhaps the welder uses a transformer with a 400 V primary (this would mean connecting 2 phases), and some other useful secondary voltage. if you connect L1 and L2 to the primary winding, say L1 to the 400V terminal and L2 to the 0V terminal i would imagine L1 meter to spin whilst not the other 2 with the welder in use as the power has been used. alternatively i might be imagining this
:confused5:

 

[gjcone44]

thanks pmac10, i think that is how it is working, one of the phases is acting like a nuetral, which does not get recorded on a meter. the welder in question needs a 65kva, supply.!, there is only a 60kva supply to the building, but they tell me it only works for 10 seconds at a time.