Stumped

[rfsign]

I am stumped, looking for any ideas. When I first looked at the sign there was a bad buzzing noise coming from the sign and the electrodes were firing but not illuminating the glass. The transformer (France1530) light indicated the transformer was working properly and it was a newer transformer. I replaced the transformer. I went through the sign to look for any shorts or anything obvious like a tube too close to another tube or wire, insulated a few different spots. I ran new leads and new connections between all the glass but had no success. I started jumping out the tubes and found that when I jumped out the tail of the letter that I could get the rest of it to illuminate. This led me to believe that this tube was failing causing the problem. I replaced the tube and when I started up the sign I was back where I started. The electrodes were firing but the sign was not illuminating. I started the process over. I checked all of my connections and even reran one of my leads because I thought I felt a buzz when I put my hand on the conduit it was running through. I jumped each piece of glass and was still unable to get it to illuminate. When all else failed I jumped the new tubes I just installed and the sign illuminated again. I checked my connections found nothing.
I believe I ruled out the assumption that there was too much footage for the transformer because while I was jumping the tubes at one point I had two long runs disconnected at the same time.

Any ideas would be appreciated.

 

[nodrenim]

You may have a problem with high voltage wire going through metal conduit. The insulation on the wire will deteriorate, due to the corona effect. This will cause the insulation to break down and create mini short circuits, to the conduit. If you have pyrex neon housings, you need to check for cracks in the housings, as these can short to the metal and cause your problem. Or if you have bushings in the metal that are old and cracked, you will have the same problem as with housings. Hope this helps. Good Luck, if you need to, call me @ 1-336-353-3284, or pm me. Peace.

 

[Sign Prophet]

Does this transformer run this letter only? Did you replace the GTO home runs to the transformer? Are you using GTO with an integral sleeve? If you are 100% sure your wiring is correct and there are no shorts in any of the wiring, then one of your tubes could be bad. I would also recommend checking the load on this transformer to make sure it is operating at 80% of it rated capacity. You will need a milliamp meter designed for checking the load of neon transformers. You want a 30 MA transformer running at about 24 MA with the neon connected. My guess for your problem is either a shorted home run or a defective tube.

 

[rfsign]

Yes, the transformer only runs this letter. I ran new leads back to the transformer. Replaced the transformer with another one that I know is working. I jumped all the tubes one at a time to look for bad glass (did not make a difference). I ran all new GTO connections between the glass.

The only time the sign illuminates is when I jump the glass in the tail of the letter which is the glass I just replaced and checked with my tester.

At one point I had 2 of the 5 pieces of glass jumped (only trying to illuminate 3 pieces) and made no difference. This is why I ruled out it as a footage problem or even shorts.

 

[Westcoast Sign Guy]

Need a bigger pic, at the same time post what's behind the wall. I would recommend you get yourself a HV probe too.

 

[Keneh]

Is the load for the transformer correct?

 

[J Hill Designs]

I've seen this caused by not having the letter bonded back to the tranny box / bad ground

 

[NSW Systems LLC]

Have you checked to see if the job is set up as a mid-point ground?
The way to check is look at the transformer and if the secondary leds those are the ones that come off the transformer. are hooked up in the middle of a set of letters and look for the mid-point ground lug there will be two wires running back to that share the same lug.
check the mid-point wires first if loose or not connected the sign will not light up but the other half will.

get back to me

Mike
NSW Systems LLC.