Flouresent lighting questions for the wizards

Ive got a shop 14' wide by 55' long

For years Ive had a series of 4' double tube florescent fixtures hanging and have had no issues with them.

The shop is unheated (California) but the winter temps do go down to the high 30s at night in the winter time on occasion. Ive had some lights have issues coming on at those temps in the past.

I scored a bunch of 8' (2 sets of (2) 4' tubes) fixtures that run on

277vts. Some 10 of them or more, with nice speckle covers that Id like to put up and replace the single 4' fixtures.

Ive been using a couple 3 tube, 4' fixures that are already 277 volts in odd areas and running them off a 240/120 single phase transformer..hooked up backwards, with no issues, for a number of years.

My "HV" (mains) standard power runs between 240 and 250 volts out in the shop off the breaker panel, but Ive been concerned about isolating the lamps so Ive used old machine tool transformers hooked up backwards.

Ive been checking the "new" 4 tube fixtures out and they all seem to fire up well and Ive got several new cases of 4' T12 bulbs in the racks along with a partial case of T8 4' tubes. Ive stuck in T8s in the older fixtures over the years and they work fine even missmatched with a T12..but I generally replace both.

So at this point in time...Im getting ready to put up the 8' fixtures..but Im concerned about how to power them up.

  1. Is it "kosher" to simply hook them to an unused 240 single phase breaker?
  2. Is it better to use a transformer and isolate them from the "mains power"?

3 If I should install a transformer...where do I find a 240-277 step UP transformer cheaply? Or several of them (welding shop needs one as well

  1. How many watts does each 4' pair actually draw? 90 watts? Each of the 8' fixtures has 2 ballasts, one for each 4' pair.

I tend to work out there at night..and with Pacific Greed and Extortion charging me far more than the national average...my power bills at HOME have been around $400 a month this summer. This with a

1hp swamp cooler motor running 24/7. (which really hurts!!!)

Id like to have lighting in the shop that will work for me..but doesnt break the bank. Work has slowed down tremendously (not had a service call in a week and a half) and its not going to get much better Im afraid...California and the US manufacturing has just declined..yet again.

Id like to find some pull chain lighting switches that I can mount on each 8" fixture to either kill the entire fixture..or just half of it (double ballests) and help keep the lighting costs down as well. Ebay has "pull chain" switches for $4 each..but that will add up fairly quickly if I install 10 lights.

Any suggestions/recommendations on setting up my lighting that will not break the bank?

Thanks

Gunner

-- "Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry

Reply to
Gunner
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Your best bet is to install T8 fixtures over your machines and switch them individually. You can get decent Lithonia fixtures at Home Depot with real ballasts for pretty cheap money, at least here in NY. Payback on using T8 instead of T12 is quick, and task lighting is also a good way to save money. Buy a fixture at a time as you can afford it.

Reply to
ATP

Gunner wrote in news: snipped-for-privacy@4ax.com:

So these fittings are intended for 277V (star) operation off a 480V (delta) three phase supply.

Many ballasts are dual rated 208/277V, so correct operation off 240V is not surprising.

As the fittings are rated for use with a 480V three phase supply, your concerns are almost certainly unjustified.

Yes - but only if they are dual rated.

Two questions, but lets leave isolation aside. You need a boost transformer to 277V (nominal) if the ballsts are not dual rated.

Any transformer with a 240V primary and a 30-40V secondary can be wired as a boost autotransformer. However this DOES NOT PROVIDE ISOLATION Asuming a 35V secondary, the primary only carries 15% of the lamp curent. If the secondary current rating is sufficient, its good, Dont worry about the VA rating. An autotransformer will be much smaller/cheaper than any other solution.

N.B. it would be preferable to use a pair of 18V transformers to boost each side of the supply equally to keep the 277V output centered on neutral. This is quite possibly not to code, so wire a suitable wall mount male connector to the lights and build the transformer in a 'portable' housing with flex leads.

Data should be on the ballast. Add them up. If in doubt, MEASURE!

HTH Ian.

Reply to
Ian Malcolm

But which voltage?

Gunner

-- "Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry

Reply to
Gunner

I would just buy new 120v fixtures. I actually have some nice indirect 277 T5 fixtures that I wanted to use but eventually decided installing a buck boost transformer and having a different voltage in the shop just wasn't worth it.

Reply to
ATP

What's the big deal? A single 24 V transformer in boost configuration will drive all the lights. 277V is 115% of 240, and 264 V (240+24) is within 5%. Standard light switches are rated for 277 volts.

80 watt lamp at 277 draws 0.2888 amps. Round that up to .3A per tube for easy calculations. 40 Watt would be about .15A. 55 feet only has room for a little over six eight foot fixtures in a single row, so the maximum load would be .6A * 6 or 3.6A if all six fixtures are on. If he used the other four fixtures over machines, that would be another 2.4A for a total of 6A at 277 Volts. You don't need, or even want isolation on the fixtures. The housings should be grounded, so a fault will blow a fuse, or trip a breaker. They used to put a fuse in some brands of eight foot fixtures, so a failure wouldn't take out all of the light fixtures. Not a bad idea, but the fuses need to be rated for 600V circuits to prevent a plasma arc inside the fuse.

You can even wire the fixtures to turn on pairs of tubes instead of all four, with some ballasts.

Reply to
Michael A. Terrell

Buying...is out of the cards at the moment. I might be able to start swapping ballasts over time...but...there is no money for changing fixtures. Seriously.

As long as I dont have to spend money..Im golden.

Gunner

-- "Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry

Reply to
Gunner

My shop is full lighted with standard 8 foot fixtures. In really cold mornings they are slow to come to full power also.

Reply to
Bob La Londe

So let me get this straight..Im very weak here...

input side is 240vts. Output side is 24 or 32vts..simple step down transformer, right?

Hook one side of the 240 volts to one 240 term..and wire a jumper around to the low voltage side and connect to (1) 24 volt term

The othe 240 hot goes to the other 240 input term..

The remaining 24 volt OUTPUT terminal then becomes 264 volts output along with the jumpered 240+24 volt tern?

Do I have that correct?

And if so...where do you recommend I put the fuse(s), on both sides of the transformer..single input and single output terminals?

Im VERY weak on transformer work. Shrug. The stroke took a lot of what I did know..away, from the looks of it.

I may..may have (3) decent sized "buckboost" transformers on a board out on top of one of the racks. Used for bucking UP machine tool voltages as I recall. Ill have to climb up and check. They were as I recall..used on a 3 phase machine..hence 3 of them.

Gunner

-- "Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry

Reply to
Gunner

I used to just brush them with a corn broom to get them to "fire"

Reply to
grmiller

Yes. Like a control or rectifer transformer used to provide 24 volts vopr a machine.

Yes. She the photo in the link to help you visualize it. You can think of it as a Variac set in boost mode, if that helps.

formatting link
sows how to connect a transformer in boost configuration. The 'H' windings are the

240 side. The 'X' windings are the low voltage secondary. If they are connected in phase, they raise the output voltage. If you reverse the phase, it will subtract from the line voltage. Both sides show split windings, so just ignore the H2 to H3 and the X2 to X3 connections if your transformer has single windings. I would put a 10 to 15 Amp fuse or breaker after the transformer, and use a 15A circuit breaker in the panel.

Feel free to email me if you have any other questions.

I would mount one in a box, if the terminals are exposed. If they have a wiring compartment, just mount it next to the breaker box & wire it in. This is like that repair I did last year to that Ineco pipe bender that was reporting low voltage. BTW, they lost a second computer in that thing. Luckily, I was able to repair the oldest one so they didn't have to wait for a replacement from Italy. I'll try to post photos of the second controller before & after I repair it. They will be posted on my Fliker account, until I start a repair blog.

formatting link

Reply to
Michael A. Terrell

Sure, but that only works in Canada!

Reply to
Michael A. Terrell

I just went out and pulled down the (3) transformers on a board (G) that were hooked up for buckboost. They are Acme 1kvas and I just downloaded the data sheet from Acme. Shows exactly how to do it..and I was right in my last post.

Thank you!! A life saver!!!

Ill put a fuse on the single input hot leg (H1X4) and one on the single output leg. ( That will unfortunately leave me the H4 hot ...hummm..no..if I put it on the input side of the H4 pass through...and another on the X1 output..thats three...hummm unless I have some doubled breakers..that will cover the input and output side with two (double) breakers. Or do you think I need to put fuses on the output side and just a double breaker on the two input lines?

What would YOU do?

According to the data..this thing in buckboost will handle 41 amps and Im not going to have more than about 15 amps worst case sceanario with every light in the shop on at the same time.

My apologies..but I appear to have just discovered another hole in my memory left over from the stroke. I know Ive done these before..quite a few of them. In fact..the 3 phase buckboost I originally installed some 10 or so years ago to get a machine up to voltage...as I recall..they had about 190 volts in the shop..and the VFD was kicking out with an undervoltage alarm..so I put this together and ran their lathe until they redid the entire shop and service..and I got to "scrap" it.

And now Im relearning how to do it!! Yippeee!...sigh. Gunner

-- "Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry

Reply to
Gunner

I would just use a 15 or 20 A double pole breaker on the prrimary, and a 15 A 600 V rated fuse in the 264V output from the transformer. If a fixture shorts, you'll lose the fuse. If the transformer fails or the wiring is damaged, the breaker will trip. It will also remove all power from the fixtures when you need to replace a ballast or socket.

Reply to
Michael A. Terrell

Why not? You are slightly underpowering them - but if they work you most certainly will not be harming them.

What do you expect this to accomplish?

How about running two circuits - one on ballast #1, and one on ballast #2 - with separate switches. You can light the whole fixture, or either half, depending how much light you need. You could also add a switch to drop out one half of the shop if you are only working in the other half, so you could have the "active" end of the shop at full or half, with the "inactive" end either on or off. Just 4 standard switches.

Many other combinations available, Just remember, the pull-chain switches NEED to be rated for 240 volts minimum.

Reply to
clare

Yup. You will have either 264 or 216. If 216, reverse the connections on the 24 volt transformer secondary

Correct. The secondary of the 24 volt trans just needs to be able to handle the full load current.

Fuse the load and the transformer secondary (which are in series) or simply fuse the parallel combination of the load and the transformer primary. If you think you need to fuse anything beyond the panel protection (fuse or breaker)

Reply to
clare

On 9/9/2012 7:44 PM, snipped-for-privacy@snyder.on.ca wrote: >> 2. Is it better to use a transformer and isolate them from the "mains >> power"? >

My parents house had all fluorescent fixtures in the basement except for a single incandescent bulb all on one circuit, that bulb was frequently blown by the mag ballast's spiking when turned off, so it can be good to isolate fluorescent fixtures if electronics are on the same circuit. MikeB

Reply to
BQ340

Except the isolation transformer will just pass the spike right through. A surge protector might catch it.

Reply to
clare

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The cheapest way would be to get a step-*down* transformer which goes from 240V to around 40V and hook it up with the primary across the line, and the secondary in series with one side of the line phased so it adds to the voltage (if it drops the voltage, just interchange the two secondary wires).

Probably easier to find ones which put out 28 VAC, which will get you up to 268 VAC -- close enough for most purposes -- especially with your slightly higher line which I think that I already trimmed out.

You really want the number of amps -- which can be higher than the Watts would indicate. Do you have a clamp-on ammeter? If so, that should tell you what you need. (The power factor in the ballast is something which I could not predict.) But because the boost transformer I described does not have to provide the current at the full voltage, it can be smaller. A 28 VAC transformer at 1A is a lot smaller than a 277 VAC transformer at 1A (28 VA vs 277 VA -- so nearly a factor of ten in the weight). And a 1A transformer can supply 268 VA boosting a 240 VAC line.

What would probably draw the least power would be LED lamps, but the price on those is far from low enough yet -- aside from you not being in a position to buy new which is all there is out there in the LED family. So it would cost you less to *run*, but way too much to

*acquire*.

Hmm ... how many relays can you find in the junk pile? Look for ones with AC coils for 24 VAC, 120 VAC or 240 VAC -- whatever you have most of. Set them up so you switch power to the relay coils from a convenient location -- so turning off the power to one set of relays will turn off half the lamps in each fixture. Turning off the power to the other set will shut down the other half. Maybe set it up so a rotary switch powers the coils. If you have a four-deck switch with five rotary positions -- you can have it so fully CCW has all the lamps off, one step up turns on 1/4 the lamps, the next step 1/2, the next step 3/4 and the final step all of them.

If you have a bunch of solid state relays, you could use them instead -- they use a lot less power (anything from 3VDC up to 32 VDC IIRC) and almost no current.

If you want to be able to do it from multiple locations, replace the rotary switch with a stepping switch. Wire it like the rotary switch, but you have the ability to push a button to step it through the positions from a number of locations around the shop. There was one style of stepping switch by Automatic Electric which had two coils. One would step it up from a rest position to any one of ten active positions, and some of them had as many as four decks and wipers. So -- you push one button to increase the light, and another to turn them

*all* off at once.

Of course, you want a master disconnect to make it safe to work on the circuits -- especially since it is possible for the SSR to fry in the *on* state -- especially if there is nearby lighting.

If you already have stepping switches like these (eBay #

120645014544), you can wire them up so if you hold a button down, they will keep stepping up so you hold the button down until it is bright enough, or until it goes dark again.

BTW For anyone looking for stepper switches on eBay currently *Beware*! A lot of what are being sold as stepper switches are in reality only the bank of contacts, without the rotary wipers, or in some cases with the wipers, but without the electro-magnets which perform the stepping.

I was trying to find examples of the 10 position quick reset ones to show you what to look for in the "pile of junk" -- but nobody has them up for sale at the moment.

If you want more details, you have my e-mail address -- or can recover it from what is posted with the instructions in my .sig below.

Good Luck, DoN.

Reply to
DoN. Nichols

I've gotten panic phone calls from Kinkos locations: "They sent me a

277V Poster Laminator and the building only has 240V - HELP!" If you really want to use up those fixtures till they die, go find yourself a 120/240V to 16V/32V "Buck-Boost" rated transformer.

They are NOT all suitable for Buck-Boost Autotransformer use - Read The (Friendly) Manual, or the nameplate for mentions that it's suitable, or get the make and model and pull up the cut-sheet before you try it.

Some craptastic Lighting and Signal transformers use thin insulation on the secondary that will break down seeing 277V to ground instead of the 32V expected. Rule #1 - Magic Smoke Escape is bad.

Give it 240V in (always use a Handle-Tie 2-pole breaker!) and wire it by the instructions for Boost, and you get 240+32= 272V Single Phase.

5V low = Close enough for Government Work.

A 1KW rated transformer will Boost like 3KW to 4KW of load - read the instructions. The transformer "load" is all used to kick the output voltage higher, and it's only a percentage of the total output. Again, Read The (Friendly) Manual, it tells you how to calculate it.

And when you get new fixtures or replacement ballasts, get 120V.

Some of the fixtures are coming stock with Universal ballasts that take whatever you feed them, be it 120 - 208 - 240 - 277V - Some even take Japan's 100V 50Hz.

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Reply to
Bruce L. Bergman (munged human readable)

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