Fluorescent lights flicker/ go out when table saw starts.

[Joe Hillmann]

My shop used to only have on set of fluorescent lights and when ever I would start the table saw they would flicker or go out until the saw was up to speed. I had planned on running a dedicated line straight to my table saw and switching it to 220 to fix the problem and then adding several more lights to my shop.

I started with adding more lights, all on the same circuit so I now have 4 sets of lights. Now when I turn on the table saw the light that was originally there still flickers/ goes out but the other three have no problem.

So my question is, what is causing the light to flicker? Is it the ballast?

[Ralph Boumenot]

Sounds like the saw and the lights are on the same circuit. When the saw starts it is drawing max amps and there isn't any left for the lights. Having a dedicated circuit for both is a good idea.

[Chuck Stone]

the ballast would be my guess. They get old. Someone told me
they should be replaced yearly, but that sounds like a lot. But
I suppose if it is used all day most days, maybe not. I know that
in offices I've worked in, they replaced them about once a year.

[Jacob Reverb]

I would put the saw on a 220 circuit. It'll fix the voltage-drop issue that's causing your lights to flicker, and it should spin up your saw faster, too. (It did with mine.)

[John Poole]

This suggests your wiring is insufficient to handle peak demands.

I recommend you take a voltage reading at your saw to make sure you are not getting a low voltage drop at the start of your motor. If you are getting a voltage drop, then your motor will have a very limited life as the surge of amps (lower voltage means more amps) running through the motors wires will exceed design capacity and you'll end up with a burnt-out motor.

[glenn bradley]

Pretty much covered here. Your saw may or may not be able to run on 220v. I will add that any machine will benefit from a properly provisioned circuit. A previous saw of mine performed the same on either a 110v or 220v circuit as long as they were properly built (breaker, wire gauge, outlet, plug and machine cord). There are many stories of troubled lights and machines that all end happily with proper electrical plant ;-)

[john bateman]

Regardless of whether that one particular lighting ballast is bad, it's not a good idea to have lights and saw on the same circuit. If you ever lose power while sawing you'll be standing there in the dark with a spinning blade and your hands pushing lumber into it.

[Jerome Stanek]

[QUOTE=john bateman;2144813]Regardless of whether that one particular lighting ballast is bad, it's not a good idea to have lights and saw on the same circuit. If you ever lose power while sawing you'll be standing there in the dark with a spinning blade and your hands pushing lumber into it.[/QUOTE

If you have them on the same circuit and you lose power to it the saw will quit also

[Duane Meadows]

[QUOTE=john bateman;2144813]Regardless of whether that one particular lighting ballast is bad, it's not a good idea to have lights and saw on the same circuit. If you ever lose power while sawing you'll be standing there in the dark with a spinning blade and your hands pushing lumber into it.[/QUOTE

If you have them on the same circuit and you lose power to it the saw will quit also

Yes, but it doesn't stop instantly! John's point is very valid. It won't be that important to you when the saw blade goes through your hand, that it was in the process of slowing down!

Also it won't meet code anywhere I am aware of. Lights should be on separate circuits, period. That goes for wall outlets in houses as well

[Chuck Stone]

[QUOTE=Jerome Stanek;2144817]

Yes, but it doesn't stop instantly! John's point is very valid. It won't be that important to you when the saw blade goes through your hand, that it was in the process of slowing down!l

So .. what, it should continue at full speed instead?
I think somewhere we got sidetracked into the irrelevant..

[Duane Meadows]

[QUOTE=Duane Meadows;2145233]

So .. what, it should continue at full speed instead?
I think somewhere we got sidetracked into the irrelevant..

The point is, if the saw or whatever trips a breaker(breakers do even fail sometimes!)... you can still see what is happening. If both the tool and lights are on the same circuit, you lose both!

If you don't care about safety, yeah, I guess you could say it is irrelevant! Me? I'd rather still have the lights and be able to see.

And, it still won't satisfy code to have your tools on you light circuit!

Obviously, with a total power failure, you are right... won't matter much, but that is no reason not to wire your shop properly. Which should also solve the flickering light issue when the saw starts, which as I recall WAS the original problem, no?

[Rian de Bruyn]

Its all to do with the harmonics of the electricity BUT lights en plugs must be on different breakers

[Jerome Stanek]

So if the lights trip a breaker while your cutting that is much saver

[Duane Meadows]

So if the lights trip a breaker while your cutting that is much saver

Well, now that you mention it, my lights are on three separate breakers. The chance of all 3 failing simultaneously is slim to none!

I just hope you are not an electrical inspector, Jerome.