Phase Current Variation

[SmokeTest]

I have a power monitor connected to the input of a 440VAC 3-phase voltage regulator. The input transformer is a delta configuration with no neutral. Is it normal to see a difference in the phase current measurements? I am observing the following: L1=0.521A, L2=1.561A, L3=1.964A.
What would be the explanation(cause)for this?
Thank you for helping me understand.

 

[busbar]

With balanced phase voltages, 3ø current imbalance is usually load based. What is the regulator powering? Of less importance, is the ‘input transformer’ separate from the regulator?

 

[SmokeTest]

I need to correct my initial thread entry.
The power monitor is connected to the OUTPUT of a 440VAC 3-phase voltage regulator. The OUTPUT transformer of the regulator is a delta configuration with no neutral.
The regulator OUTPUT is supplying a welding machine's 3 phase tranformer input primary winding whose secondary is providing the necessary voltages for the torch and circuitry of welding machine. I am observing the different phase curents with the weld machine in an idle state and when it is in a weld state. Sorry about the confusion.

 

[jbartos]

Suggestion: There are special voltage regulators for welders that regulate the welder input voltage via the variable impedance transformer (inductor) voltage regulation.
Visit

http://www.eng.uts.edu.au/~joe/subjects/eet\pas_aut97.pdf

for Problem 1

http://www.welders.co.uk/arcwelders/sip.htm

(notice a variable inductor at SIP 500)
etc. for more info

 

[jlazucena]

Have you check for harmonics?