small three phase transformers inrush current
small three phase transformers inrush current
(OP)
Gentlemen
we use a plasma cutting equipment that may be seen from the supply side as a three-phase transfomer. For safety reasons it might be switched on and off quite frequently, say every ten minutes in worst cases.
The primary voltage is 400 V, the size of transformer is 50 kVA.
Is there a proven and cost-effective solution to limit the inrush current?
Will a set of three resistors by-passed after a short time do the job?
Not a real problem, I am trying to improve and reduce potential causes of trouble since we have a lot of delicate equipment around.
thanks for your time
we use a plasma cutting equipment that may be seen from the supply side as a three-phase transfomer. For safety reasons it might be switched on and off quite frequently, say every ten minutes in worst cases.
The primary voltage is 400 V, the size of transformer is 50 kVA.
Is there a proven and cost-effective solution to limit the inrush current?
Will a set of three resistors by-passed after a short time do the job?
Not a real problem, I am trying to improve and reduce potential causes of trouble since we have a lot of delicate equipment around.
thanks for your time






RE: small three phase transformers inrush current
doesn't plasma welders work with very high inrush currents? I dont see how by avoiding the inrush current, you will be able to run your welder. This is the way I understand your commnent, if you can be more specific please state so...
Regards
RE: small three phase transformers inrush current
Regards
RE: small three phase transformers inrush current
fab; Certainly a switched in/out resistance will do the trick. Might be interesting too to just turn the unit on and off at just the correct point in the power cycle. You'd only need to monitor one phase obviously. I wonder if anyone has tried that..
Otherwise you'd just run an "ON DELAY" relay to cut in a shorting contactor around your resistance 1 second after the ON switch is turned on.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: small three phase transformers inrush current
RE: small three phase transformers inrush current
RE: small three phase transformers inrush current
"It has to do with when the transformer was turned off in the power cycle and when it is turned back on"
I kept thinking of just the plasma welder not the whole picture (engineering basic mistake, jajaja!)
Regards