Ot Safe light fixture for inspection

[2004sk4]

A recent fire has everyone in a panic. The fire was started by the spring end of a 8 ft t12 fixture coming loose which sparked and cause the edge of the product to catch fire.

Right now we have two 8ft t12 fixtures mounted end to end.

The request is to put one enclosed fixture in their place.

They make a 8 ft t8 fixture with (4) 4ft bulbs in it that have locking clips.

Does anyone know where i can get a 12 foot t8 enclosed fixture that hold (6) 4ft bulbs. I am afriad if i use a 8 and 4 ft enclosed fixture end to end that their will be a void of light between them which would make it hard to see minor defects.

We have tried some led lighting but they were not bright enough for inspection purposes. I might not have found the right company yet.

Any help would be appreciated

 

[Steve Bailey]

These folks make good stuff. They might be overkill for your application, though. They have experience with LED as well as fluorescent lighting.

http://www.lcdoane.com/Default.htm

 

[rsdoran]

I would look at replacing it with low bay HID, one fixture can offer better lighting in many situations, unless you need color correcting.

You can always mount 3 4ft, 2 6/8ft or whatever in an overlapping pattern and there will be no light gaps. Instead of inline do something like this -------________-------- with the ends not butted but side by side.

 

[OkiePC]

What Kinda Inspection?

If this is a vision system application, consult the digital camera/controller vendor/manuals...

I am afraid if i use a 8 and 4 ft enclosed fixture end to end that their will be a void of light between them which would make it hard to see minor defects.

Often, a vision system will require a high frequency lamp. And any change in the lighting will usually mean some tuning of the controls of the automated inspection software.

Also, many vision systems are monochrome, but if it is a color inspection system (Keyence for example), using a contrasting backlight will make for excellent results, but you gotta teach that color to the controller to make it work well...

If it is human inspection, altering the light should not pose a problem...so, what about just modifying them?

Sounds like you got some $50 fixtures. you need some that can handle vibration, not, snap together Home Depot variety stuff.

We use sleeves over products, and sometimes bump up the lumens because they do dampen the light slightly. So with the protective sleeve, if a lamp falls out, is doesn't contaminate the product with broken glass/chemicals. Most of ours also had cages under the lamps too.

I bet the whole lamp fell out with the end connector right? If the lamp had dropped only two inches, there may have not been an arc, but I would buy fixtures whose connectors are positively fastened to the fixture, and rigid along the length. You can't have dangling joules around a flamable product in the 1st place...

Okie

 

[2004sk4]

We are using the 6 bulb hibays on the sides of the folding frames.They work great. The design of the machine does not allow a low bay fixtures to be mounted. As in the past when (3) 4 ft enclosed fixtures are end to end there is about 4 inches worth of shadowing between them.

This is a human inspection area above a narrow catwalk so staggering them will not work either. All of our lights are shattershield bulbs with wire ties around them.

The machine vibration caused the ceramic spring end of the light to get weak and break. The slightest sparks will set the jute off which did happen. This product is very hard to put out cause of the lint and oil that is along with it.

 

[OkiePC]

http://www.hubbell-canada.com/wiring/killark/PDF05/7SecL/L164-L169.pdfhttp://www.thelightingcenter.com/products/*/*/1613

Maybe these will lead to a version with your specs...didn't see any 8 footers at the tops of those links tho....

Hope it helps!
Paul

 

[leitmotif]

A recent fire has everyone in a panic. The fire was started by the spring end of a 8 ft t12 fixture coming loose which sparked and cause the edge of the product to catch fire.

Right now we have two 8ft t12 fixtures mounted end to end.

The request is to put one enclosed fixture in their place.

They make a 8 ft t8 fixture with (4) 4ft bulbs in it that have locking clips.

Does anyone know where i can get a 12 foot t8 enclosed fixture that hold (6) 4ft bulbs. I am afriad if i use a 8 and 4 ft enclosed fixture end to end that their will be a void of light between them which would make it hard to see minor defects.

We have tried some led lighting but they were not bright enough for inspection purposes. I might not have found the right company yet.

Any help would be appreciated

OK if fluorescant fixtures burn up your product when they fail why keep using what causes problems??

This may be extreme and I am SURE there is going to be some cost but what about fiber optic?? The source is over there out of the way and out of the "dusty" area so there would be no ignition source in the inspection area.

Another idea from spray booth manufacturers. Explosion proof lights are too expensive. A sheet of glass is mounted to the outside of the booth ceiling and the fixture mounted onto that.

From my meager experience with lighting fixtures (schools, US Navy, industry) I have observed that if they have a GOOD cover any failure inside stays behind the cover and does not get out. Did your fixtures have covers on them or do you just have the plastic sleeves over the lamps?

BEFORE you do any changes in the lighting GET a lighting survey done. I know it is a QC area but the first complaint you will get is that it is not bright enough, too much glare, the color is wrong, etc etc. A lot of lighting beauty is in the eye of the beholder. Before and after readings of at least lumens and better yet color spectrum (if you can get there) will go a long ways to answer the "psychological based" complaints.

I do not have the magic answer but I sure can tell you the mistakes I (and others) have made.
Maybe I do not know WHAT to do but
I surely know some stuff about what NOT to do AGAIN.
Dan Bentler

 

[rsdoran]

I stop with "I can't"

Does not allow is "I can't"

I said HID low bay.

If several 4ft flourescent can be mounted then one or 2 HID low bay definitely can.

Can't never could.

 

[2004sk4]

The current light fixtures are 277volt t12 8 foot non-enclosed fixtures. The bulbs are shattershield with wire ties around them, The main problem with a 8 ft fixture is the spring end becomes brittle over time.

"This may be extreme and I am SURE there is going to be some cost but what about fiber optic??"

leitmotif What fiber optic company's have you had good experience with.

Rsdoran, You are right i dont need to say i can;t before i see the type of fixture you are talkiung about.

Which hid low bay would you recommend. The product with is 13 ft wide. and i only have about 6 inch wide place to mount a light

Okic. Do you know how much the lightingcenter lights are?

There seems to be more choices than i was thinking. This forum is very successful because alot of purchasing mistakes can be avoided by other people experiences.

Thanks

 

[milldrone]

2004sk4,

Just to clarify a few things
1. The fixture needs to be less than 6 inches high,. Is this correct?
2. Is the width restricted? If so what is the measure?
3. You indicated that a 8 foot fixture and a 4 foot fixture placed end to end casted a "shaddow" between them. How does this work with 13 foot product? It seeems to me that there wood be 6 inches on each end that would be "shaddowed". In your original post you indicated that you were using two 8 foot fixtures. so there must be some extra length so play with. Can you explain how these two 8 foot fixtures did not cast a "shaddow" between them?
4. What is the height between the product and the light?

 

[keithkyll]

HID's are nice. Ron (rsdoran) said Low Bay. I've only seen the standard size, which is similar to a street lamp. Perhaps you have room for the low bay type of fixture.

Ideas if you're stuck with your current setup.
1) Do you have room to add shock mounts? If so, they would help with the vibration problem. If you have room for a double setup, you could almost eliminate vibration by getting special shocks that are tuned to cancel each other out (one at 9 Hertz, other at 4.5 for example). Someone else may be able to expand on this idea.
2) Signs use a high brightness type of 8 foot lamp. I think the fixtures are stronger.
3) Consider mounting the fixtures upside down (facing up). Create a reflector out of 1/32 inch Stainless and curve it. With the correct shape, there won't be a dark spot in the middle.

 

[Lancie1]

We are using the 6 bulb hibays on the sides of the folding frames.They work great.

I agree, the relatively new fluorescent High-Bay fixtures have high intensity lamps that provide as much light as the old 400 watt high bay metal halide fixtures. I would think that some fluorescent high-bay fixtures would be an ideal solution for this lighting problem.

 

[2004sk4]

Just to clarify a few things
1. The fixture needs to be less than 6 inches high,. Is this correct
YES.
2. Is the width restricted? If so what is the measure?
The current setup is 16 ft. I need to take atleast a ft off each end to eliminate a salvage wrap from hitting the fixture.
3. You indicated that a 8 foot fixture and a 4 foot fixture placed end to end casted a "shaddow" between them. How does this work with 13 foot product? It seeems to me that there wood be 6 inches on each end that would be "shaddowed". In your original post you indicated that you were using two 8 foot fixtures. so there must be some extra length so play with. Can you explain how these two 8 foot fixtures did not cast a "shaddow" between them?
The current fixtures are non enclosed so there is next to no gap between the lighting ends. The enclosed fixtures would space the bulb ends apart 4-6 inch becuase of the extra housing. The side lights we have installed will cover the difference from 12ft to 13 ft.
4. What is the height between the product and the light?
The light is mounted 2 inches below the product above a inspector catwalk.

I have some room to install shock mounts but unsure about the hz thing.

 

[keithkyll]

I have some room to install shock mounts but unsure about the hz thing.

Everything has a natural resonance. In optics, an anti-vibration setup uses 2 shocks per leg. One has a resonance of 4.5 Hertz. The other has a resonance of 9 Hertz. Any vibrations cancel each other out. An Engineer could probably explain it better.
I probably went too far. This setup is a bit more exotic than what you need. Simple rubber mounts should do the job. I would think very soft would be best.

What's needed first is a deep analysis of what is causing the ceramics to break? Are they moving within the mount (glue them in), or is a resonant frequency causing them to break (add shocks to cancel this frequency)? Are the vibrations being transmited by the framework, or sound noise?
From what you said, none of this is happening.
My first guess is the sheet metal is too thin, and the flexing is causing the springs in the socket to flex until fatigue failure. Adding stiffeners to the sheet metal should stop this, or remake the mount plate with thicker metal. That's why I mentioned sign (commercial) fixtures. They're usually built better (i.e., thicker metal).
Redesign with a different product is difficult because of space limitations and uniform illumination requirements. Correcting the current design is easier.
A fire indicates further failures can't be tolerated. Serious anaylysis of the cause of failure should enable you to properly cure the problem. It may take a combination of the solutions mentioned above.
In addition, someone mentioned a safety shield of some type. This should be seriously considered, and may be manditory to maintain fire insurance. Almost any light source could be a source of ignition in the event of failure. Containment is probably the only thing the Fire Marshall will accept.

 

[keithkyll]

My first guess is the sheet metal is too thin, and the flexing is causing the springs in the socket to flex until fatigue failure. Adding stiffeners to the sheet metal should stop this, or remake the mount plate with thicker metal.

The 8 foot lamp is a solid rail. The mount plate needs to be just as solid, as well as the sockets. This forms a complete box.
Make the 'box' solid, so no corners flex. This will minimize the movement of the springs.