480 VAC pilot Lights 1

[DanijelM]

I have old (40y) TG control panel with about 30 pilot lights.
About 10 of those lights are 480VAC. What i want to do is to bring all of those lights to the PLC HMI. However 480 VAC presents the problem.
Cannot modify the source of the 480VAC pilot lights.
Short of installing step down transformer on every light what are my other options? Could not find any interposing relays with 480 VAC coil.
Any feedback is appreciated.
Thank you

 

[waross]

What type of sources or circuits are behind the pilot lights? For example, if these are giving contactor status you can often add contact blocks to the contactor.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[dpc]

You might want to really think about getting rid of those 480 V pilot lights and any other 480 V pilot devices you have still in service. That is trouble waiting to happen.



David Castor

http://www.cvoes.com

 

[djs]

Most 480 VAC pilot lights I know of have transformers in then to reduce the volatge down to six volts. The actual bulb is a six volt bulb. You can verify this by inspecting the buld from one of the pilot lights.

The alternative is to use a small IEC type contactor with a 480VAC coil. Not as small as an interposing relay, but in a crunch will work.

 

[jraef]

I agree. With the exception of Neon pilot lights, nobody makes or made 480V filament bulbs, they would have had a small 480-120V transformer on the back of the pilot light and used a 120MB (Miniature Bayonet or BA9s base) or 120PSB (Push Slide Base or TS5 telephone base) lamp. I could just leave those little transformers in the circuit somewhere since you already have them and use the 120V to power 120V PLC inputs or at least allow the use of more readily available and inexpensive 120V interposing relays.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[Bobngavan]

You can use GE CR104P pliot lights which are readily available. These are 30mm. They are available with 480VAC input. The transformer is part of the assembly.

 

[jraef]

The transformer is part of the assembly.

As it is with every other 30mm pilot light mfr.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[dpc]

The fact that there is a transformer on the light assembly does not eliminate the 480 V terminals on the back of the light. 480 V pilot devices are a safety hazard and should be eliminated at every opportunity.

Some industries are moving away from even 120 V ac control circuits and converting to 24 V dc.

David Castor

http://www.cvoes.com

 

[DanijelM]

Update.
The prints I had for this Panel date back to 1954. However, somewhere along the lines someone changed 480 VAC lights to 125 VAC.
Thank you for tips