Re: SRSG motor - HELP!!!!!

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

Original poster: "BunnyKiller by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bigfoo39-at-telocity-dot-com>

Tesla list wrote:

>Original poster: "Mr Gregory Peters by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
>
>Hello all,
>
>Today I was running my coil and getting solid 8 foot arcs, when
>suddenly, and rather destructively, the SRSG motor died. 
>

snipperzz..


Hi Greg...

by chance, did you have the cord which feeds the motor a bit long and 
was it coiled up to make things tidy? and was it in close proximity to 
the primary ( a few feet ?? )

I has modified a motor from a Sears bandsaw to use as my SRSG and it ran 
very well for quite some time ( never got hot, warm but no hotter than 
normal use as a bandsaw) . I had set my coil up and used a different 
extension cord ( a bit long) and coiled up the excess cord and hung the 
excess on the lower part of the cabinet. After about 2 minutes of 
running, POOFFF  the motor smoked and died rather quickly. An autopsy of 
the motor showed that the windings in one spot had arced to the rotor 
and there was also arcing from the rotor to the bearings to the case... 
 seems strange that 120 volts could arc across 1/4" of air to the rotor 
from the windings in the case...  

my only assumption was that the excess extension cord coiled up in close 
proximity to the primary was enuf to induce a fair amount of voltage in 
the cord from the primary field...   thus finding its way to the 
"grounded" rotor via the bearings and motor housing.  

something to think about......


Scot D