I was carrying out an A chain alignment on a Monee projector, and on this particular machine there are two tag strip terminals located in the exciter lamp chamber. Most rational people would probably use those for the low voltage DC to the exciter lamp, as they are convenient for the lamp, and also not safe to put anything but LV on as they are entirely uncovered. For anyone who doesn't kow the type of terminals I'm talking about, they are similar to those found in the front of a Century sound head. The company that installed these machines had done something unbelievably stupid. They had used these terminal for the 240V AC supply to the lace up lamp! Worse still is the fact that they sourced that 240V from one of the incoming phases, with no circuit protection, so the supply to the lace lamp is protected by a 30A MCB!!! Whilst lining up this head, my finger must have touched these terminals, and then BANG! Result, one scorched hand, and avery pissed off engineer.
I am astounded by the stupidity of anyone who could leave un covered terminals, live at 240v/50HZ in the operating chamber of projector. This really beggars belief. It's a miracle that no one has been electrocuted by these death traps before. All four projectors in the booth are wired this way.
If anyone is ever working on these piles of junk, please be very very careful. I've no looked into the rest of the wirign in this booth, and it really is unbelievable. Two core, 1.5mm2 cable has been used to wire the CP to the amps!!?? No shield, and it's so heavy that it keeps pulling itself off of the connectors. In fact they only seem to have this cable, as everything has been wired with it, with the one exception being the solar cells.
Unbelievable, and almost criminally dangerous.
You were saved by the fact that you didn't have the current go through your body, as much less than one ampere of current can cause electrocution under the wrong conditions:------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
I'm glad you didn't get anything worse than the shock. If you had been grounded just right, you might not be reading this now!
When I bought my house, it had the upgraded electrical system that was installed in 1948 with plug fuses.
I had to replace a couple of outlets that were so old that they actually made the outlet cover warm. I removed the 4 plug fuses, and went to take off the outlet cover. I received a nasty shock! I went back to the fuse box and found melted pennies behind the fuses. After pulling the main fuse, and testing to be sure it was now turned off, I pried the pennies out of the fuse sockets. I used the original fuse box for a year, then replaced everything.
I'm amazed that there was never a fire in this little wooden house. It would go up fast.
Bruce
In my youth playing with gear I shouldn't have been playing with, I received zaps-a-plenty, the HT side of a V8 engines ignition is one which I will remember for a long time! Those however were caused by me being young and stupid. This was caused entirely by negligence.
I am still questioning in my head, "did somebody really leave it lke that?"
The wheels have been set in motion, accident reports filled out, and an electrician has been brought in to make it safe and report on any other unseen horrors which may be lurking.
As I said before, unbelievable.
I was once told by someone from another comapny here that they will not service anything they did not install. It's incidents like this that make you see why.
Normally, most people in the medical profession will tell you that if you experience an electrical shock, one should go to an emergency room in the hospital just to make sure all is well. People have died several hours after electrical shocks, even though they felt fine. You did the correct thing when you went for a check-up.
When I was in the United States Navy, I got "Hit" with 3 phase 208 400Hz power. It blackened my hand a little, and scared the crap out of me. It was a nasty one. SOP was report to the Navy Hospital immediately, either by ambulance or a co-worker hauling the victim there.
A rule of thumb. Never assume a low voltage terminal has low voltage. As you discovered, it was a nasty voltage. Also, treat all electrical circuits like a they are alive. An innocent looking electrical circuit can be just as dangerous as a loaded .44 magnum pistol.
Paul
I myself had a nasty shock last year when attending to a lamphouse that was failing to strike - turns out even though i'd isolated the entire lamphouse, one circuit was still live from another feed, and the back of my hand just brushed the live part. had to go get some fresh air after that. was ok after some fresh air and a smoke. although i appreciate lecky shocks are ALL different - different V's and A's, Yours must have had a few more Amps than mine! 2 important facts i have learned though- 1. Electric Shocks are called 'Shocks' for a reason! and 2. Boy does my multi-meter get used a lot when working on otherwised 'isolated' equipment!
Seriously, another thing I think about quite often is the fact that when we have to work on the back (off operator's) side of the projector we sometimes find ourselves in a potentially dangerous situation:
ALL of the controls for the system are usually on the operator's side of the machine, completely out of reach of somebody working on the back side. If you come into contact with a live wire or get your clothes (or body part!) fouled in the machine you are SCREWED! There's probably NO F***ing way you are going to be able to shut off the power!
Whenever I introduce a new person to working on something on the back side of the projector I always tell them to be aware of that. Furthermore, I tell them NEVER to work in the building alone. In case of trouble you can at least holler for help, even if the chances of being heard from the booth may be remote. At least there's a chance you'll be eventually discovered. Keep a two-way radio or a cellular phone within reach.
I'm surprised that the projector "bit" you like that! I'd never think that there was anything higher than 12-24 volts inside the sound head, except for the power to the motor! All the framing lamp transformers in the projectors I work on are not on-board the projector head. They are all inside the console somewhere.
Glad you turned out okay, brother!
Personally even if the machine left the factory that way, I'd have altered things to remove that voltage from those terminals.
Like Randy said, most lace lamps these days are LV, point of fact I often modify older machines to use a LV lace lamp, for the very reason of removing all HV from the film side of the projector.
Unbelievable.
Josh
Just seen on the UK projectionists’ website that in your part of the land, sadly the listed ABC Muirend closes 21st October.
http://groups.yahoo.com/group/cinemationlist
Most of the ABC's have gone, all the ones I ever worked in are closed, that last one I was in, Lothian ROad, Edinburgh, was demolished, but is set to rise again with a four screen multi on the site. Those were good days, and good old barns of theatres, but their day is gone, sadly.
I advise any other Monee users to check the terminal strips located in the exciter lamp-house. There is no way this should be used for mains voltage. As Pete says, this has been used for powering the lace-up lamp within the projector. If you find there is mains routed through these connectors, you have two options-
Cover the strip connectors with electrical insulating tape or-
Just disconnect it - Its what i have done, those lamps are useless anyway.