Intellabeam 700HX Sparks Flying

[Bubby4j]

I had a very exciting evening, when I was adjusting one of my Intellabeams suddenly there was lots of arcing between the body of the Intellabeam and a truss (luckily I was standing on rubber!). I know that part of the problem is that the power the Intellabeam was connected to was not grounded (not making that mistake again!).

I looked inside and didn't see any wires contacting the body. (Was just a quick inspection, will be looking at it thoroughly later). I don't think that the breaker tripped. (Unless someone turned it back on before I checked.)

As I see it, there's 3 possiblities:

1. The truss was energized
2. The Intellabeam body was energized by a wire directly contacting it
3. Some other weird electrical thing happened inside the Intellabeam leaking to the body

I check the truss against a ground with a multimeter shortly after the event occurred, and the potential was only 1 volt. Unless the breaker for the wire that could have potentially been touching the truss tripped, this couldn't be it.

Any ideas?

Pictures:

 

[LavaASU]

With the ibeam not plugged in, meter continuity from the hot and neutral pins to the body.

 

[Bubby4j]

With the ibeam not plugged in, meter continuity from the hot and neutral pins to the body.

I also already tried that, 0 ohms from hot & neutral. Which makes me think where ever the fault was has been fried. It arced for several seconds before stopping.

One thing I should try though is a bare spot on the body, or simply try between ground & neutral, and ground & hot.

 

[Bubby4j]

I just realized I did that test with the cover open, so the safety interlock would keep the cord isolated from the fixture. I need to try this again in a bit.

 

[Bubby4j]

Okay, found the issue. Testing resistance wouldn't have worked anyway for this issue.

The screw for the handle on the outside was making contact with the ballast, really this is a dumb design. This would not happen if you had the yoke attached to the fixture, but I did not.



The question remains: Will simply operating the fixture without the handles in work, or is the ballast permanently damaged & not safe to operate?

 

[Les]

Wow! I can't believe HES/Lightwave Research made that mistake! My guess would be that the ballast is damaged. Maybe only slightly for now, but you could have another fireworks show in the future.

 

[LavaASU]

Okay, I can't quite see what happened there (as far as to the ballast). I'd remove the screw (completely) and inspect the ballast. Take a picture of the area of the ballast where the screw was making contact and post it. Chances are if the ballast will work normally its okay to run it without the screw there obviously. I'd definitely replace that screw with a shorter one or remove handles completely though.

 

[Bubby4j]

Okay, I can't quite see what happened there (as far as to the ballast). I'd remove the screw (completely) and inspect the ballast. Take a picture of the area of the ballast where the screw was making contact and post it. Chances are if the ballast will work normally its okay to run it without the screw there obviously. I'd definitely replace that screw with a shorter one or remove handles completely though.

That's what I was thinking. I'll do that.

 

[Bubby4j]

Okay, popped it open this morning. I found that the outer layer of insulation is a bit burnt, but it appears as if the inside windings are okay.
I couldn't get a very good look as I didn't want to damage the insulation, the main concern I have is that the connection between the black wire & ballast is higher resistance than it should be, causing it to heat up when in use.
What kind of insulation is it? Is it okay to take the outside layer off to inspect the connection and then use electrical tape to tape it back on?

Pictures (Click to make bigger):

 

[FatherMurphy]

My memory of working on these units years ago is that temps inside the body near the ballast tend to get warmer than PVC electrical tape is likely to stand up to, you'd run the risk of the tape melting/burning during longer shows. Come to think of it, one of the more common failures of the power boards I saw was the solder joints between the power terminal strip and the PC board heating and failing/cooking the card substrate. Anything you try to use for repairs should be rated for higher temperatures than the normal everyday grade hardware store stuff.

700 HX i-beams represent the state-of-the art circa 1990... although they were built well enough to last some 25 years and counting, they did have their drawbacks.

 

[Les]

Come to think of it, one of the more common failures of the power boards I saw was the solder joints between the power terminal strip and the PC board heating and failing/cooking the card substrate..

I've seen that failure mode. Maybe related, but if you have any of the push-in terminal strips, replace them with the screw-type. They're harder to work with but the socketed ones seem to come loose and cook themselves.

 

[jhochb]

Good Morning Bubby4j
DO NOT try to use that transformer again. If the outside melted like that I wouldnt trust it
Once a transformer / ballast burns up its history.
Les
The IBeam didnt have the terminal strip option that was the Cyberlight.

 

[LavaASU]

Good Morning Bubby4j
DO NOT try to use that transformer again. If the outside melted like that I wouldnt trust it
Once a transformer / ballast burns up its history

I respectfully disagree. I would absolutely try it. Obviously being very careful (making sure under no circumstances could it shock a person, in an area free on combustibles, ect). As far as the light, I can't imagine it's really worth repairing, so not a lot to lose on trying it...

 

[Bubby4j]

I contact Don at lightparts (Intellabeam genuis), he said to resolder the wire if needed, and then to check voltage output on it. (This side is evidently the autotransformer.)

Really it's not burnt up, only the insulated melted & one wire was damaged. When I do try to power it up I'll of course have it on an insulated surface, not be standing by it when I plug it in, and have a fire extinguisher ready.

If something does happen it shouldn't last for more than a couple seconds, the fuse and/or breaker should take care of it. Plus, it's on a grounded outlet now. I'll update when I find results.

The awesome about these lights is that I got a fabulous deal on them (I actually paid less for 4 of them than I would pay for 1 bulb for them.)

The sad thing is bulbs are insanely expensive for me. (I'm actually just a high school student )

Also, I think this might be good to repair the insulation on the autotransformer:
Amazon.com: 3M Glass Cloth Electrical Tape 27, White, Rubber Thermosetting Adhesive, .50-Inch by 66-Foot: Home Improvement
Supposedly it's good up to 150C, which is what the wires going into the autotransformer are rated to.

 

[Les]

The IBeam didnt have the terminal strip option that was the Cyberlight.

Are you sure? I once had 8 I-beams and about half had those push-in strips on the PSB (half of those were melted). Maybe we're thinking of different things.

 

[Bubby4j]

So, I tried turning it on. It powers up and works, but after a minute the fuse blows. I measured current with a multimeter as it's turning on, it's sucking 21 amps! And this is without the bulb connected! That's a problem.

 

[jhochb]

Good Morning Less

Its been a long time but im sure HES started using screw terminals in later Cybers


Bubby4j

21A is WAY too high even with the lamp running

Be afraid, be very afraid

8p

 

[LavaASU]

I'd let Don know about the 21A and see what he says. If there is PFC in this is could be bad and contributing.

 

[Bubby4j]

I don't think it could be the PFC, I've ran without the PFC before and without the lamp on it's normally at no more than something like 6 amps (can't remember). I'm seeing what Don says about it pulling so much power.

I wish I had a meter that could see amperage without having to actually connect to the wires, then I could see if it's something that's connected to the transformer or if it's the transformer itself.

 

[LavaASU]

I don't think it could be the PFC, I've ran without the PFC before and without the lamp on it's normally at no more than something like 6 amps (can't remember). I'm seeing what Don says about it pulling so much power.

I wish I had a meter that could see amperage without having to actually connect to the wires, then I could see if it's something that's connected to the transformer or if it's the transformer itself.

Can you borrow a clamp meter from someone?

Or buy this:
Fluke 321 | eBay
Ideal Industries Inc 61 732 400A AC Clamp Meter | eBay