48" Fluorescent lamps and Switches.


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At work and for a customer’s permanent install, I have been requested to install some switches on some architectural dual lamp/dual ballast fluorescents. Not a problem, intent is for a photo studio to control the lamps separate for output reasons, and with dual ballasts that’s simple enough. Simple project, install a suitable grade of switch in-line before the power to the ballasts. Got lots of left over switches that came off Mole Light audience blinders which are sufficiently heavy duty... This should be sufficient for a fluorescent fixture mount, I say I’ll do the project.

Than the by way of the sales person that has already sold the project, the customer specifies what switches he wants to use and a red flag goes off in the back of my head. Unlike in other stuff however, that red flag while theorized as not such a good idea I can’t express for certain why.

Customer wants to use rotary based pull chain and rotary based turn switches such as one might find on a table lamp or pull chain from a overhead light or fan. It’s just something about the rotary snap switch both have in common that I for some reason beyond home owner grade switches have a concern about when used on a 40w fluorescent lamp. Don’t know why yet. Any ideas or the real reason I shouldn’t do this?

My theories are ranging that the spring snap contact of the rotary switch, and the higher amperage startup of a fluorescent lamp, even if the switch is rated for the amperage, it will tend to wear out the home owner grade switch faster. The heat by way of resistance to good contact and phase harmonics plus start up amperage... But of this, while the switch probably won’t last as long as a more heavy duty one, the switch still should function to some extent sufficiently - at least as sufficiently as in that of a 240w or more watt home owner grade eight lamp light fixture in cold start using a rotary switch.

Than again, at least on the pull chain switch, I understand that this fixture will be mounted overhead and for some reason they want localized control over it instead of running the fixture to a wall switch. I won’t be installing the gear and it’s theorized that it’s a temporary install, nor will I be dealing with the perspective chain hanging down in the photo... Not aware of a more industrial grade of pull chain switch... perhaps I take apart a porcelain pull chain for standard surface mount lamp socket it will have something more industrial in a pull chain switch, but other than that possibility I’m told they would loose any wireless remote and a wireless wall mount switch is out of budget.

So, short of me re-reading a bunch of texts read in the past that no doubt were telling me something that now sticks in the back of my head as a concept but doesn’t come to mind, any ideas on why not to do this sufficient the customer won’t want to do it?

Follow up to this is that today I installed a chain hanging fluorescent fixture over my metal working area at work. That’s up to code or at least to the point that work doesn’t want me running conduit and instead it’s cord run across a beam than down the wall. Like the flexibility concept which is ok to a point as long as that concept allows me to at some point do a land grab for more space. On the other hand, conduit is easy enough to install, move and re-install as needed, at least for me who doesn’t make the rules about such things.

None the less, I left the thing on by accident tonight after I went home. I’m not going back in, turning off the alarm etc. to turn this off once I noted it from an outside window and already in my car. Each worktable or desk in my area has a set of localized switches at the work table that kills the power to it and is easy enough to see as one leaves for the night or is easy enough to remember as one goes home. The metal working area on the other hand is different. I go back there at random to cut or drill stuff, or just find raw materials and am in and out or there all day long dependant upon what’s going on. It’s a fluorescent so turning it off and on frequently or even motion sensing the area wouldn’t work. Plus there is shop cats which wander about the building while nobody is there. A pre-set timer switch also wouldn’t work, it’s too random between the standard and long hour days. Today on a Sunday, it was only 5.1/2 hours, on Monday it will be 12.1/2 or more.

I’m thinking something like a four hour timer switch to control the lighting in the back work area. I have a one hour timer already mounted on my 3.6v cordless screw driver battery charger and it seems to help battery life in a high harmonic disturbance environment. - Lots of computers and moving/strobe lights. This turning off the power completely for the small batteries, over that of surge suppressers or the isobar power strip I have on my 14.4v battery chargers - doubtfully working better than nothing helps a lot for battery life. Four hour periods of time on the fluorescent would probably be sufficient in me turning it on no more than twice a day, but as with the above, not so sure how healthy fluorescents run off such a timer switch would be, or if it’s the best proper use of it.

Such gear would be more industrial but any thoughts?


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For your timed switch... I have this cool switch I bought at Home Depot for my porch light. It replaces a standard wall switch but has a built in 7 day digital timer. You could put those back in the corner so that the lights always turn on and off at a certain time.

As for the fluorescents... is there a reason they didn't just buy something off the shelf with the chain switch already installed? What you describe sounds like what I have hanging in my garage. Sorry I can't help you with the electrical theory issues.


CB Mods
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I have to admit that I am having the same sort of gut reaction to the switches. And I'm not 100% sure what is causing it either, so let me see if I can work it out (these are really thoughts on paper, so no guarantees they will be logical). Fluoros are an inductive load. So much of the time, switch derating becomes necessary. I think this may be a factor. Second thing is that what what I gather, we are talking about a domestic grade switch that isn't the most solid thing in existence. Now the switch might be good for a domestic application of turning the lights on maybe once or twice a day, but in a commercial application where they might be getting what 10, 20, more operations over the course of the day? Sounds to me like a recipe for premature failure. Now this can be either a good thing or a bad thing. Good thing if you want a service call in the foreseeable future, bad thing if you don't. If it weren't for the desire for an inline control, then you could do almost any type of switch and have it control a relay or contactor to do the actual load switching

As far as switching Ship's metalworking lights goes, I tend to think that a timer should work. Most of them just run with a relay to switch the load so I can't see how that would muck up the harmonics or anything along those lines... no different to a switch I would have thought. I know that down here they make industrial timers so I can't imagine why they would not over in the states. I'm not quite sure what you mean about the nasty harmonics in your building, is this to say in a nutshell that the timer might be affected by said harmonics and hence loose some functionality? If so, perhaps a mechanical timer would be better, though I don't know if they exist in a suitable sort of thing for this. Hope the food for thought is of some benefit.


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thinking along my lines. Bought a McMaster Carr 12hr timer switch, it said in the instructions that it was rated for fluorescent loads. Same gut reaction and I attempted to relay to the sales person about the perspective limited life of a home owner grade switch on such gear which he was concerned with by way of it not lasting as long, but there is nothing more industrial on the market. No store bought fluorescent fixtures have either of these types of switches, much less have a dual ballast for controlling the fixtures indipentantly. KinoFlo type fixtures is what these emulate - only for a perminant less money spent install. I'm told the customer is very cheap but wanting only high quality - of course. GE discontinuing the 95CRI Chroma 50 didn't help the matter either.

Anyway, bought the timer switch... guess I'll install the home owner stuff but make it known to the buyer that I don't recommend this type of switch. The red flag is beyond life of the switch concern, there is something about such a rotary operating switch that I don't remember the details of but remember sufficiently that I wouldn't do it short of the customer specifically wanting it.

Very much grey area in the NEC and ethics of wiring stuff I suppose. It will work and work safely as long as it's start up amperage does not exceed the rating of the switch, just got this feeling beyond terms of usage switch life that I shouldn't be using it. This also beyond the concept that it's a engineered product and modifying it voids the UL listing.


For the perm install at the customer site, McGill makes or made a good quality pull-chain switche. You local eclectrical supply house should stock them or a suitable replacement.

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