This is my first post, and I have been through pages of archives and am still searching for an answer.
If my problem is not allowed for discussion, I won't take it personally.
Short version, purchased an external quench furnace with element damage with electrical components missing.
It came with a step down Delta 480v/90 amp to Wye 57.7v/ 180 amp transformer.
I am powering this transformer with a 75kva Delta to Delta step down transformer in boost form, line side 240v (45amp fused) to 480v load side (15 amp fused) at an estimated 37.5kva.
My main current is a 400 amp, 3 phase 240v/208v with a wild leg that comes from a 2 wire line through a 15 and 25kva transformer from my local REC.
I have 3 ribbon elements .750 wide x .067 thick x 25' long, each separately wired to the Wye transformer, phase to neutral.
I have 57.5 volts phase to phase, drawing 90 amp from room temperature, up to around 750 degrees in 15 minutes and that's as high as it goes.
These high nickel elements have very low resistance and I have been unable to make any other connection work without blowing fuses or popping breakers.
I even tried resistors on the neutral end to slow the current, but only gained about 100 degrees.
I have to get the voltage and current working before I can move on to designing a scr/ssr controlling circuit.
Does anyone have any idea what I need to do?
I just can't think of any thing else and no one around here has an answer either.
Thanks in advance
If my problem is not allowed for discussion, I won't take it personally.
Short version, purchased an external quench furnace with element damage with electrical components missing.
It came with a step down Delta 480v/90 amp to Wye 57.7v/ 180 amp transformer.
I am powering this transformer with a 75kva Delta to Delta step down transformer in boost form, line side 240v (45amp fused) to 480v load side (15 amp fused) at an estimated 37.5kva.
My main current is a 400 amp, 3 phase 240v/208v with a wild leg that comes from a 2 wire line through a 15 and 25kva transformer from my local REC.
I have 3 ribbon elements .750 wide x .067 thick x 25' long, each separately wired to the Wye transformer, phase to neutral.
I have 57.5 volts phase to phase, drawing 90 amp from room temperature, up to around 750 degrees in 15 minutes and that's as high as it goes.
These high nickel elements have very low resistance and I have been unable to make any other connection work without blowing fuses or popping breakers.
I even tried resistors on the neutral end to slow the current, but only gained about 100 degrees.
I have to get the voltage and current working before I can move on to designing a scr/ssr controlling circuit.
Does anyone have any idea what I need to do?
I just can't think of any thing else and no one around here has an answer either.
Thanks in advance