Series inductor with drive question 1

[gfdona]

I have a piece of equipment that essentially IR heat lamps driven by SCR's. In series with the equipment on the main incoming power feed (480v, 400 amp) is a .054mH inductor with 15 kvar delta caps on each side configured as in a pi filter. If my calculation came out right this is set up for the 25th harmonic. What is the purpose of this circuit??

 

[jbartos]

Suggestion: Visit

http://www.rficorp.com/Filtchar.pdf

http://www.rficorp.com/tubulars.htm

for:
A Pi filter is usually the best choice when high levels of attenuation are required and where input and output impedances are similar values. It should not be used with switching circuits.

The PI filter will attenuate the higher frequency that might cause EMI interference.

 

[busbar]

Without some in-service field measurements, it’s a bit hard to make a concrete statement.

Are there any as-built drawings / design calculations / operating history as evidence? Is their some aspect of operation that is unacceptable or suspect?

15KVAC on a 400-ampere circuit seems kind of "dainty".

 

[gfdona]

Sorry for the delay, I was out. I talked to the new equipment manufacturer who acquired the design from the original manufacturer and did not get much out of them other than "because I said so". My real question is does this filter help me in any way other than RF mitigation. Does it help with transients/spikes to the equipment/ harmonic mitigation ( I have 5th banks at the unit sub)etc..