Conventional Fixtures Bottoms of lamps being burnt; S4; 5/50

[GHSStageManager]

In my HS's auditorium, we currently have 16 ETC S4 Jrs. On about 4-5 of these fixtures, the pins on the bottom of the lamps are scorched and burnt. (See attached photo)

What could be causing this? Is it a bad dimmer channel, or a power problem? I feel like it couldn't be a power problem since the other fixtures are doing fine...

Thanks,
GHSStageManager

[media]http://img694.imageshack.us/img694/6917/20100125182356.jpg[/media]

Also: a photo of the base of the fixture that that lamp came out of

[media]http://img709.imageshack.us/img709/6362/20100125181551.jpg[/media]

 

[jonliles]

It appears that you have had some type of corrosion in the lamp base at some point in time. This is causing arcing in the socket. This will make lamps difficult to remove, add to premature failure, and will worsen over time. The solution is to purchase a new lamp socket and install it the new socket will have a new whip on it that will need to be terminated with the appropriate plu type (stage pin, edison, etc...). Contact your local Lighting Supplier - your school system may even have an account set up with Barbizon.

Best of Luck!

 

[Morpheus]

it is definitely corrosion/arcing. You need to replace the socket as soon as possible if you want to maximize the life of future lamps...
Basically, the corrosion causes the contact to not be at 100%, so the electricity has to arc across, which causes more corrosion, which causes more arcing, which causes.... yea, it's a bad cycle. I've seen it a lot on the mini-strips i've got here at my school, (side note, when you can't get them to keep working for one lousy flippin show you need to look at replacing something).
Another thing is to make sure you correctly seat the lamp and use the retainer clip! I've worked on some old S4 bases (pre-retainer clip) and they would eventually loosen on the lamp, and corrode over way faster than they do now.

 

[ajb]

In addition to what Morpheus and jonliles said, you also need to throw away the lamp. This type of problem spreads like a venereal disease, if you try to use that lamp in a good socket, that good socket will develop the same problem. Likewise, a bad socket will turn a good lamp bad as well.

 

[GreyWyvern]

This really isn't too terrible to deal with if you have S4s. Parts are everywhere you look. ...rant begin... However, if you are stuck with blasted Colortran 5/50s, it is a different story. I still can't find parts to replace a handful of bad lamp bases. /rant

 

[wolf825]

Also to add, the cause of this issue can be numerous...including simple age and wear from the friction of inserting and pulling out the lamps and the pins/socket getting pushed in...but it is also caused by dirt/oils and moisture getting in, sometimes from handling the pins of the lamp when they get changed out. It can also be when the lamp is not seated properly or the electrical contact & flow is not good for whatever reason. The socket or pin is not making good contact and that can begin the process of what you see via arcing.. It can also come when your plug connector/wire has loose fittings, or the wire is toasted--which adds resistance and inturrupt the electrical flow and cause intermittent contact to complete the circuit...this can go down the chain to the lamp sometimes..

This "pitting" type of degradation just only gets worse and as others have stated before, and can spread to otherwise OK fixtures by swapping lamps with these damaged pins around. It requires both the replacement of the socket and a new lamp. Its not unusual to hear the sizzle of the arcing in the cap when the fixture is on or is being brought up to full. You should be checking your plug connections as well--make sure they are not overheating ad the wires are secure cause they can loosen over time if they were not snugly secured or crimped... Remember electricity is a kinetic and moving force--the connection points can literally vibrate themselves loose over time if they are not snug.


-w

 

[derekleffew]

...rant begin... However, if you are stuck with blasted Colortran 5/50s, it is a different story. I still can't find parts to replace a handful of bad lamp bases. /rant

Really? Does the Colortran 5/50 use something other than the readily-available TP-22 or TP-220 socket?

OSRAM SYLVANIA - NEW HIGH PERFORMANCE TP22-XL and TP220-XL SOCKETS

 

[GreyWyvern]

Really? Does the Colortran 5/50 use something other than the readily-available TP-22 or TP-220 socket?

Will either of those fit into the 5/50 base?

Dave

 

[derekleffew]

From the attached document:

Socket shall be precision type TP-22 UL
recognized, steatite insulated, die-cast aluminum
construction, rated for 600 Volts, 1,000 Watts,
200°C, continuous operation. Rated seal
temperature shall not be exceeded.

Anyone out there who has replaced a socket in a 5/50 lamp cap?

 

[Les]

Will either of those fit into the 5/50 base?

Dave

Judging by this quick google search (Colortran 5/50 Socket), the 5/50 uses a standard lamp base as derekleffew pointed out.
colortran 5/50 socket - Google Search

For an exploded diagram and parts list, click on the second link (Functions Maintenance), which is a PDF file.

 

[derekleffew]

...of bad lamp bases.

...a standard lamp base ...

/rant The base is the part of the lamp containing the electrical contacts. The part the lamp goes into is the socket. /rant off

 

[GreyWyvern]

So I should be able to just pull the old socket out of the assembly and put a new one in, right Derek?

Les, that is the same pdf I attached to a reply for someone last night regarding lens placement for different degrees.

I have been looking for the entire assembly rather than just the socket.

Thanks guys.

Dave

 

[Les]

/rant The base is the part of the lamp containing the electrical contacts. The part the lamp goes into is the socket. /rant off

I call(ed?) that a Lamp Cap. Don't judge me.

 

[Les]

So I should be able to just pull the old socket out of the assembly and put a new one in, right Derek?

Les, that is the same pdf I attached to a reply for someone last night regarding lens placement for different degrees.

I have been looking for the entire assembly rather than just the socket.

Thanks guys.

Dave

Yep, just remove the old socket, and install the new one, running the new leads through the fiberglass sleeve. Note that the old socket will come out with the old leads attached, so you will need to remove the connector from the whip. Discard the old socket and leads. Well, were it me I'd clip off the old leads and keep them because, you never know.

 

[chris325]

How much do those socket replacements cost? We've got a bunch of lamp bases that aren't functioning, and it looks like socket replacements may fix at least some of them. (I think we're up to around 8 bases that don't work, translating to around 8 fixtures that can't be used.) Also, if this does work, what would be the proper procedure to go about replacing a 5/50 socket?

 

[Les]

How much do those socket replacements cost? We've got a bunch of lamp bases that aren't functioning, and it looks like socket replacements may fix at least some of them. (I think we're up to around 8 bases that don't work, translating to around 8 fixtures that can't be used.) Also, if this does work, what would be the proper procedure to go about replacing a 5/50 socket?

Last I checked they cost between $10-$20 each. Any major stage lighting supplier will carry them. I can't comment on the procedure of replacing a socket on a 5/50, having never done it. It shouldn't be too much different than the reverse order of removing the socket (literally). You shouldn't have to do any wiring other than reconnecting the connector. The ground wire will be bonded to the plate that the socket mounts to (or some other part of the lampcap housing) and it should remain that way - no need to mess with it. Make sure it's tight though while you're in there. It will most likely be riveted to the plate that the lamp socket mounts to, assuming it is built at least somewhat like a 360Q.

Do you have anyone on campus that might be familiar with this type of work who could supervise you? Failing that, you might try calling Leviton for their advice. They might even be able to point you to an online repair manual.

 

[chris325]

If they are that cheap, I will certainly recommend purchasing some to my school's TD. (This is certainly not a procedure I would do on my own. Under the supervision of the TD, maybe.)

Unfortunately, finding replacement lamp bases if we have any that still don't work with a new socket will be near impossible. The biggest problem I have with the 5/50s is that there really aren't replacement parts, and many of our shutters have bit the dust.

 

[Les]

To find the bad sockets, grab your favorite flashlight and pull out every lamp cap and with the lamp removed, check the contacts inside the socket (this is what you need the flashlight for). If they look anything other than shiny silver or gold, put them on the watch list, they may need to be replaced. But what you are really looking for is pitting. The surface the lamp pins contact should appear smooth. If it doesn't, it's bad.

Try contacting Production Advantage for your replacement parts. The fixture is still being made, surely the parts are available. Bad framing shutters are not a new thing or exclusive to Colortran/Leviton -- it's a condition that plagues any fixture with an aluminum reflector.

Quality Theatrical Supplies and Equipment?Production Advantage, Inc.

 

[derekleffew]

As Les said, try Production Advantage. Their Instrument Parts Catalog (.pdf attached) lists quite a few 5/50 parts.

The complete Lamp Burner Assembly (Lamp Cap) is Cat#INPT-0294, Leviton Socket Assy, 5/50 Series, $89.85.
For shutters, Cat#INPT-0293, Leviton Shutter Blade Assy, 5/50 & 213, $6.25/each.

One would think (hope) any Leviton dealer should be able to source these.

 

[GreyWyvern]

I guess my trouble is that I have only been looking online and not calling any place. I also never thought to look for Leviton parts, only Colortran.

Thanks alot Les and derekleffew!

If I can get some ordered this week and done soon, I will post any tips I think might be helpful for chris325.

Dave