3 way on sign disconnect

[TwinCitySparky]

OK- I dont work on many signs at all and now have a question with one. I have an 8 lamp T-12 sign that has not worked in years. The owner said he thinks one lamp was lit up about 4 years ago... :roll: I'm thinking the two ballasts need replacing. I've traced power from the photocell thru the disconnect switch on the bottom of the sign. While checking switch, I was surprized to find it is a 3 way (with 3 wires connected) -- I figured I'd find an old single pole instead. Scratching head...

Is this some sort of ballast discharge design for servicing - OR?

Thanks in advance for replies/any additional info.

Man! My supplier sais its a "no go" on the original 4 lamp HO Signa ballasts and suggested rewiring sign with 4 new two lamp units. Internet search finds original Signa units ranging from $120.00 to $350.00 a piece! >>> Yikes!

 

[ultramegabob]

did you find a second three way switch somewhere? if not how is the switch wired, is it wired so you are selecting between the photo eye and constant power for a manual override?

 

[TwinCitySparky]

No 2nd switch around anywhere and only one hot and neutral feeding up the pipe from photocell below.


Edited to add: The switch has 3 blackwires fed to it (visable thru switch hole in bottom of sign.) Sounds like I may be tearing it apart...

 

[TwinCitySparky]

I think it might be the previous maintanance guys creation. Run 4 bulbs till one blows, then the owner can grab a ladder and switch the 3 way over to the other 4 bulbs to effectively get twice the bulb life. Sign runs at 1/2 brightness but has half the required maintanance. I wonder if this is common?

 

[chris kennedy]

While checking switch, I was surprized to find it is a 3 way (with 3 wires connected) -- I figured I'd find an old single pole instead.

Violation of 225.38(D)?

 

[TwinCitySparky]

Violation of 225.38(D)?

Most definetly.

I am leaving them with the bright, fully functioning 2 ballast 8 lamp original design.

With a new single pole disconnecting everything. :wink:

 

[Podagrower]

How about 600.6?

 

[LarryFine]

Most definetly.

I am leaving them with the bright, fully functioning 2 ballast 8 lamp original design.

With a new single pole disconnecting everything. :wink:

I'd trace those wires just to be sure before simply tying them together. It's not impossible that the switch alternated between two sources instead of two loads.

Maybe one leg is through a photocell for normal use, and the other leg is full-time hot for daytime troubleshooting. I know it's a long shot, but it's still a possibility.

Anyone who has worked on commercial exterior lighting knows what a pain it can be to cover that photocell hung about 20' above the ground. Box on a pole, anyone?


Added: At least give them a wiggy test, with the switch in both positions, of course.

 

[TwinCitySparky]

I'd trace those wires just to be sure before simply tying them together. It's not impossible that the switch alternated between two sources instead of two loads.

Maybe one leg is through a photocell for normal use, and the other leg is full-time hot for daytime troubleshooting. I know it's a long shot, but it's still a possibility.

Anyone who has worked on commercial exterior lighting knows what a pain it can be to cover that photocell hung about 20' above the ground. Box on a pole, anyone?


Added: At least give them a wiggy test, with the switch in both positions, of course.

Larry - Just one hot and one neutral feeding up pipe from photocell/junction located 4' down the support pole, below the sign. Note post #3

- As far as the switch, definetly 2 load wires and a hot. The 3 way I believe was someones not so bright idea. No pun intended.

 

[jrannis]

Maybe they were setup for turtle lighting. Is it a costal area?

 

[TwinCitySparky]

Maybe they were setup for turtle lighting. Is it a costal area?

Well, not exactly...

He could be looking to the future though. Those icebergs are melting really fast.

:grin:

 

[glene77is]

Violation of 225.38(D)?

'Shall ... Indicate ... Open or Closed ... Position'
may not apply if BOTH positions are a 'Closed' position.

Still, This Situation Should Be Indicated by tagging the wires
or labeling inside the work box.

This is a danger to the maintenance person.

 

[glene77is]

In support of your comment:

How about 600.6?

So far, I don't see a Disconnect, properly labeled, in sight of the Sign.
I only see a Control Switch, without proper labeling.

I don't think the 225.38 (D) would apply,
BUT,
600.6 may indicate a Violation of the intent of the NEC.

Any Sign without proper Disconnect and Labeling (if required)
poses a hazard for (untrained) maintenance persons.

Electricians (experienced, licensed) would check the lines for 'hot' conductors
before trouble-shooting the circuits.
Most of us would kill the circuit,
before working it.

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