Experts I'm gonna need some clarification regarding the ferrite core. I have a transformer that both primary (stator) and secondary (rotor) winding are attached in ferrite core and have 1:1 turns ratio. While I was working with it I noticed that primary winding is leaking on its cylinder housing, I used megga-ohmmeter to check the insulation of primary winding to cylinder housing and I got <1Mohm at 500Vdc. While continuing the check I figured out that the ferrite core itself is leaking as well to the primary winding. I tried as well to check the ferrite core itself and I got ~1.5Mohm well I was not expecting that it would give me some resistance as I believe that it has high insulation and it is made of ceramic mixed with either iron, nickel, zinc or manganese but the high insulation turns out to be true in low voltage multimeter only.
My questions are:
1. What is the breakdown voltage of ferrite core?
2. Is there specific insulation value for ferrite core when testing it with megga-ohmmeter? I tested it with 250Vdc and got same value with 500Vdc.
3. Is it the same material as the low voltage surge arrester?
4. Is it porous? Because when I wrote a mark on it using temporary marker it sucks the ink.
5. What would be the effect of bad insulation between winding and ferrite core?
6. I am thinking of laminating the ferrite core to isolate the winding and eliminate the bad insulation between them, will it be effective?
For sure I will do some test to see how a bad insulation between winding and ferrite core affect the transformer but before that I need your opinion. I cannot rely on my instincts and my own understanding for now as I really need to understand more deeply regarding this and two or more heads are better than one. I know you all have a big head to help me with my problem.
Thanks,
NHB
My questions are:
1. What is the breakdown voltage of ferrite core?
2. Is there specific insulation value for ferrite core when testing it with megga-ohmmeter? I tested it with 250Vdc and got same value with 500Vdc.
3. Is it the same material as the low voltage surge arrester?
4. Is it porous? Because when I wrote a mark on it using temporary marker it sucks the ink.
5. What would be the effect of bad insulation between winding and ferrite core?
6. I am thinking of laminating the ferrite core to isolate the winding and eliminate the bad insulation between them, will it be effective?
For sure I will do some test to see how a bad insulation between winding and ferrite core affect the transformer but before that I need your opinion. I cannot rely on my instincts and my own understanding for now as I really need to understand more deeply regarding this and two or more heads are better than one. I know you all have a big head to help me with my problem.
Thanks,
NHB