neon light

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jcole

Senior Member
Hey guys and gals.

Trying to learn how a neon light works.
A few questions:

What is a PK housing?

What is a hage connector?

What is a GTO cable?

Have a friend who owns a liquor store and he called and said L-I-Q was not lit up on his L-I-Q-U-O-R neon light. Never really messed with one but I assume it works alot like a flouresent but uses neon gas in the tubes instead. I assume there will be a ballast or starter to ignite the gas but I think if it was the ballast it would not work at all.

Done some research but I dont know the answers to the 3 previous questions.
Any pictures or advice would be appreciated.
 

480sparky

Senior Member
Location
Iowegia
Google is our friend:

PK Housings are the glass receptacles that accept the electrodes of a neon tube. These glass shells insulate the high voltage that fires the neon from the metal cabinet.

pk_housing.jpg


Hage connector: An electrical connector is disclosed for luminous displays having one or more gaseous electric discharge tubes provided with electrode contact bearing ends and disposed within a letter or sign housing mounted at the exterior side of a building wall. An electrical housing for a high tension transformer and electrical raceway is mounted at the interior side of the wall and rigid metal conduits extend through the wall and have their opposite ends secured to and in communication with the interiors of the letter and transformer housings for accommodation of a high tension conductor. The improvement of the present invention includes a dielectric conduit for the high voltage conductor and having a length and dimension for removable telescopic mounting in and support by one of the rigid metal conduits and having a right angularly related open ended dielectric receptacle or socket at its outboard end to telescopically receive one of the electric tube ends so as to support the display tube substantially parallel to a mid-plane of the letter housing, the dielectric conduit and the metal conduit cofunctioning to position and support the display tube in the letter housing substantially parallel to the center plane thereof.



GTO cable is the high-voltage stuff used to wire neon signs....

http://www.paigeelectric.com/Tuf-hideGTO/subcategory91.aspx
 
neon is relatively straight forward as long as you remember you're dealing with 3kv-50kv. Interesting things happen at those high voltages so good insulating practices should be observed as an arc can jump several inches. The only components are a high voltage transformer and the tube which is just a glass tube filled w/neon that has wire in each end to apply power. Tubes are wired in series to a length determined by how high the transformer voltage is. If the length is exceeded then multiple transformers will be used as it sounds.

Insulation and transformers tends to "break down" with w/age. Tubes are very fragile and crack easily in handling, and the wires coming out the ends of the tubes are thin/fragile and tend to break since they are thinner than the insulated wire connected to them.

It sounds like he has 2 transfomers so I'd normally:
1. voltage check power to transformer (stay away from HV)
2. turn off & inspect the dead tubes for signs of cracks.
3. turn off working transformer and turn on unlit transformer.
You should hear it humming/ feel static electricity if its ok.
Buzzing can be caused by arcs to the frame which you may be able to see if its dark enough, also look for bad insulators where conductors are supported by frame.
4.Try exchanging transformers (check nameplate first to verify same output voltage)... if the "bad" one will light the "good" tube its good and if "good" one won't light the "bad" tube then problem is probably a bad tube or wiring. A cracked tube in a series string can be temporarily bypassed with a HV jumper wire, since a tube of air gives almost infinite resistance. :wink:
 
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220/221

Senior Member
Location
AZ
Caution: It feels like a spark plug shock if you get into it.


Generally the failure is the leads from the transformer. The PK glass gets cracked/wet and the voltage starts arcing to ground. I USED to repair neon but it is too much of a pain. I even made a tool to extract the PK connectors out of PVC, a long eye bolt, nuts, washers and a piece of hydraulic hose.
 

DIRT27

Member
Location
Ca
My Dad was an electrical sign contractor and I have worked for a sign shops in the past and have quite a bit of experience with service and installs.

Best advice is let an electrical sign contractor fix the problem. Neon is really simple but the high voltage can be dangerous as far as fire problems. The high voltage end can have a direct short and not trip any OCPD. New style transformers have GFI with an LED on the transformer to help determine the problem. There are also some testers that come in quite handy, like a neon tube tester that you just touch to the glass on the tube and it will light part of it up if the tube is still good.

PK housings are a pain and are hardly ever used in new applications any more.

The neon system is really simple and only a few things can really go wrong. Primary power the 120 or 277 supplying the transformer. IMO this is where the electrician should stop and also this something a electrical sign contractor will have an electrical contractor fix. Bad transformer. Burned GTO wire or bad connection. Bad pk housing. The last but not least bad, broken, or burned up neon unit.

You probably won't be able to go to the local supply house and pick up any wire or parts for the neon sign at your local supply house and if they can get it will be really expensive. I know some of the local sign contractors won't sell those things to an electrical contractor because they believe it is out of there scope of work , have seen bad or unsafe repairs from electrical contractors and/or don't want an electrical contractor stealing there work.

If you are still interested in doing it I will post some really easy steps to follow to help trouble shoot it. The best part is the best tool to help trouble shoot is a piece of GTO wire you can test transformers with it and for bad neon if you don't have a neon tester. I'm guessing unless you are doing your friend a favor (Free) you won't be saving him any money. A real electrical sign service guy will be able to fix it in one trip unless the neon is bad then he will have to have new piece of neon bent at his or subed out shop. BTW if neon is bad you will have to find a neon bender to repair or bend a new piece of neon for you.

I have to go work now if you decide to do it let me know and will help as much as I can.
 
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