Re: MOT pri, sec insulation rating

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Is it really good to 20KV, or was that the "hi pot" voltage?

It's unlikely that the primary (110V) winding to core insulation is good
for that much voltage (cost considerations).  And, since one end of the
secondary (HV) winding is connected to the core, it's just the insulation
from the other end to core you have to worry about, and that's going to be
2-3 kV, typically.

Tesla list wrote:
> 
> Original poster: "J Whyte by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<xoom321-at-hotmail-dot-com>
> 
> I found some older SEARS, Kenmore Microwave XMFR's....manufacturing company
> "Toshiba Co (Jpn)" says that the XMRF's winding insulation is good to 20
> kVDC. NOT BAD!!!
> 
> These Toshiba MOT's are HUGE!! However I have a slight problem with my new
> formers!
> I'm only getting 4" arc's on a single 1.25 kW XMFR (on 120VAC), not 8"
> (which was achieved with a VERY small MOT!") and this troubles me! I am use
> to 6-8" electrical arcs at 2-2.5 kVAC. However the cap does say
> .98uF at 1900 WVAC, but shouldn't the transformer be outputting more voltage
> out of curcuit?????
> 
> Any ideas on this?