Shunted vs non-shunted fluorescent sockets


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Old 05-16-21, 07:48 AM
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Shunted vs non-shunted fluorescent sockets

I was trying to install ballast bypass LED tubes, first figuring whether the existing wired sockets were shunted or not in order to get the wiring correct for single end installation.

The sockets each had one wire going to them, and there was no wire jumper within the socket, or going from socket to socket. So I figured they had to be shunted in this case, but the meter indicated no continuity. (I checked the meter, and probe to probe continuity was ok.)

So this doesn't make sense to me. Am I missing something here?
 

Last edited by Gen; 05-16-21 at 09:54 AM.
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Old 05-16-21, 11:29 AM
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When using electronic ballasts..... only one wire is required to be connected to the tube. Although the sockets are two pins and the tubes are two pins..... they only need one at each end to start the arc.

When installing replacement LED tubes..... many come with replacement sockets.
If not... they are not expensive.

You need to determine what type of replacement LED tubes you're using.
One type gets 120v at only one end of the tube. This requires a non shunted two wire socket.
The other style needs 120v at opposite ends of the tube. With this style.... any socket can be used as they are only using one pin at each end.
 
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Old 05-16-21, 12:49 PM
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Thanks Pete. I was hoping to not replace sockets...but oh well.

On another note, your depth of knowledge is quite astounding. So like I'm curious...do you just see or experience a trade condition or situation in writing one time, and remember it forever? Or how has your knowledge developed that you store so much info?

On my own end, I have a fair knowledge base, but don't always incorporate info from one experience or reading...
 

Last edited by Gen; 05-16-21 at 01:50 PM.
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Old 05-16-21, 03:04 PM
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I'm an active electrician and installer so I do see some of the same problems over and over.
I have been installing customer supplied LED tubes which is how I know there are different types.

The ones I bought from depot get their power at one end. I like those the best.
They also came with prewired sockets with white and black wire.
 
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Old 05-16-21, 05:52 PM
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The type of LED lamps we like the best is fed from each end, hot on one side and neutral on the other. These can use both shunted and non-shunted sockets. It makes the bypassing of the ballast much simpler. Just connect all the wires going to one end of the fixture to the hot and all the wires going to the other end to the neutral. No replacing the sockets required.
 
 

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