Re: [TCML] frailty of NSTs

[Mddeming@xxxxxxx]

In a message dated 3/24/08 8:54:19 P.M. Eastern Standard Time,  
teslatech@xxxxxxxxxxx writes:

Hello

I have some questions about NST failures. I haven't had  one yet but was 
wondering what characterists they
have when they do  fail. Do they just suddenly stop working or do they become 
intermittent?  Is there a way
to determine NST health after years of operation in a Tesla  coil?

Thanks for your time.

Vinnie



Hi Vinnie,
 
The most common forms of failure are on the secondary  side.:
1) for one side or the other of the secondary to fail open due to  a break.
2) for one side or the other of the secondary to short out due to a  burn 
through that spot welds turns together.
3) cracks in the potting material that allow arcing to the case or  between 
layers.
 
Failures can be sudden or progressive, but all tend to occur  in fairly short 
order. The spark gap arc becoming rapidly weaker of  stopping altogether are 
the main symptoms.
 
There are a couple of easy tests that pick up a majority of the  problems.
1) Check the DC resistance between each HV terminal and ground. If there  is 
more than about 5% difference, you have a problem(possible shorted  section. 
If one side measures open, you have a break.
2) Attach a wire to the case ground terminal and pull an arc from each HV  
terminal in turn they should be very similar to each  other in size and strength.
3) check the "tar" inside for cracks, splits and excessive wear. heat to  
refill cracks or use oil.
 
 
Matt D.
 
 
 
 
 
 



**************Create a Home Theater Like the Pros. Watch the video on AOL 
Home.      
(http://home.aol.com/diy/home-improvement-eric-stromer?video=15?ncid=aolhom00030000000001)
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla