Re: [TCML] No-load NST's

[Sfxneon@xxxxxxx]

Phil,
 
My point exactly. They changed them so that they cannot be modified in  the 
field, or by any practical means by the sign company or the sign  owner. 
They're not really concerned about how they are used outside of  their intended 
purpose. 
 
GFCIs, called Secondary Ground Fault Protection (SGFP) on most NSTs,  are 
required by the NEC (National Electrical Code) and UL 2161 spells  out the 
Underwriters Laboratory standard for neon transformers, if anyone  wants to Google 
it to learn more. Sadly, this was an attempt to reduce the  amount of neon 
related fires caused by shoddy installations by untrained,  uncaring installers. 
There's such a lack of pride and knowledge nowadays by  so many people in the 
business, that UL was forced to try to remedy the  situation by trying to make 
NSTs "fool proof", which also made them a real pain  in the backside to use. 
UL 2161 is an ever changing regulation trying to  keep up with new developments 
and situations, so you are likely to see more  changes in NSTs as time goes 
by. 
 
Another change that UL 2161 brought about is the floating secondary  
midpoint. Before that, the midpoint of the secondary was grounded to the case,  but 
now it is an insulated terminal. This secondary "ground potential" output  
terminal is connected internally to the fault sensor, and it must not be  
earth-grounded, unless you yank out the SGFP device first. However, some NSTs  with 
SGFP may work fine for coiling as long as there is equal current on both  sides 
and very little leakage to ground. 
 
Tony Greer
*************

In a message dated 6/27/2008 4:10:27 P.M.  Central Daylight Time, 
FIFTYGUY@xxxxxxx writes:

<<  If somebody goes through the trouble of  unpotting  an NST and removing 
the GFCI circuit, I don't possibly see  how the NST  manufacturer could be 
liable. It would be one of the first  things investigated  in case of a death 
or 
serous injury, and any  tampering would be obvious.

I consider it a lot quicker and easier to  bypass  the brakes on my car by 
cutting the lines than it is to unpot  and bypass  the GFCI in a typical 
modern NST. And the car manufacturer  has a deeper  wallet... >>
 



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