ECN Forum Forums Photo Discussion Forums Electrical Nostalgia Avalon Theatre - Part 2

Get a load of those bakelite fuses! Are those CLEARSITE fuses?

Hemingray:

Good call on the fuses. Yes they are clearsite fuses. The only spares left in the theater are modern style though.

It says something about the quality of the original workmanship that a majority of the fuses on the lighting circuits are still intact!

To cintinue the commentary:

#10: A close-up of the contactor busses. Beautiful layout and decent clearances (the pic angle gives the opposite impression.) I need to mention that the way this system is layed out is the dimmers and deadfront mount through the booth wall, then there is a working gap of about 28", then the cabinets holding these contactors and fuse panels. There are overhead busways (at about 6' above the floor) between the two cabinets. The contactors and fuses face INTO the rear of the dimmer board. More on that later...

#11: The plate style resistance dimmers....and yes that copper buss is live!

#12: Close up of the dimmers. The handle rotates the double sliding contacts(180 degrees apart) over the buttons, which are attached to the resistance elements imbedded in the ceramic. They are designed to dim the rated loads to dull glow, not full black. For complete blackout, the respective contactor is opened.

#13: This is the dimmer for the blue wall wash, which suffered an arcing failure intense enough to MELT the ceramic!! If memory serves, the contactor which flamed out in the pervious thread was also on this circuit.

#14: A plethora of plug fuses. A surprising number are still original.

#15: A closeup of some plug fuses and the disconnect switches for same. IIRC the switch disconnects the power to the cartridge fuse which acts a a sub-main for the select plug fuse circuits. The clearance to the cartridge fuse and that door is extremely tight, you wouldn't want to try to pull that fuse hot!!

#16: And here's the motor which drives the grand master dimming linkage which allows for smooth dimming of many circuits. This can be controlled at the main board, at EACH of the three film projector locations, at the spotlight location and at the switchboard on stage! Activating it results in a loud clunk from the contactors on the left, a deep hum from the motor and squeaks and groans from the dimmer linkages!

As I'd mentioned, working space is tight behind the dimmers and in front of the contactors. The dimmer bays are open for ventilation, and you have to be very careful when walking thru or working in that area to avoid hitting a live busbar! I had a safety spotter with me when I took these pics to make sure I didn't back into anything live.

Again, it does say a lot for the original designers and builders that the majority of this system still works and with very little attention. I seriously doubt that any of the modern stuff today will still be operational in 75+ years!

Whoa Tony!!,
Now that is cool.
Thanks for the pics mate.

I used to do a show every year in a 1923 era building with a dimmer system very similar to this.. As with this one, much of the original wiring was still servicable, althought there were some notable exceptions, such as the multicable to one of the X-rays (overhead 4 circuit border lights).

This facility had some more modern dimmers added for additional control, although the installation of those was a bit sketchy..

I used to bring in a complete lighting system, with a touring dimmer rack of 48x2.4k dimmers, multicable, fixtures, control board, etc.. I tied in power directly off the live busses in the power room, which was full of contactors as shown in the previous series of photos.. The tie-in was done hot, using Mole lugs, as the only way of de-energizing was to kill all power to the entire floor. Unlike this installation, I had 5-6 feet of working clearance.. It was actually one of the easier tie-in's that I have done, despite it being a hot tie-in.

Mole lugs are lugs designed for the motion picture industry, that slip over a busbar, and clamp down with a bolt. It used to be common to have junction boxes with several compartments, each with a short section of bussbar, onto which the mole lugs were clamped, similar to these:

Lugs http://extranet.mole.com/public/index.cgi?cmd=view_category&parent=-1899-1950-1966&id=1967

Spider boxes http://extranet.mole.com/public/ind...;parent=-1899-1950-1951-1979&id=1987

Distro boxes http://extranet.mole.com/public/ind...t=-1899-1950-1951-1979-1988&id=12186 http://www.mole.com/backlot/pages/1000ampsled.html
manufactured by Mole-Richardson, a longtime supplier of motion picture lighting equipment.

Just to be clear doing any of that work hot is very bad idea.

It is also a OSHA violation if you are not self employed.

Great pictures, thanks for posting them and explaining them.

Bob

Thanks for posting these pics; the younger crowd simply can't imagine how anything was ever controlled without using mysterious black boxes of electronics!

Likewise, there WAS life before circuit breakers.

That this stuff is, even today, perfectly safe and adequate says a lot for the original design. Sometimes people forget that :real" electricians actually consider the customers' application- rather than doing the absolute code required minimum!

Ahh, yeah I kinda figured those to be Clearsite fuses. I have a 30A one hangin around here somewhere.

A big you're welcome to all who commented and again thanks to Bill for posting these. I also sent in some more pics, of the projection equipment and old motor-generator there which is also still fully operational.

As I'd mentioned in part 1, those contactors are the main source of trouble there. And so far, neither the building maint. super nor I have been able to locate any kind of spares or source for replacement parts. The current line of thinking is that they'll have to somehow adapt modern open contactors to repalce the ones that failed.

As techie mentioned, to de-energize this would take out (in this case) the entire booth [lights too!] and a good portion of the mezzanine level. I guess sparkies back then worked things hot a lot more than we do today. (Of course, we tend to survive longer now too.)