Film-Tech Forum ARCHIVE: Christie CH20 Phase Conversion

This is topic Christie CH20 Phase Conversion in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Joshua Waaland (Member # 287) on 05-17-2011, 01:27 PM:

I acquired a CH20 console over the weekend and I took the panel off to see what the rectifier input phase was rated. It is a three phase supply and I need it to run on single phase input. My thoughts are this, gut the rectifier and all of the outdated electronics. Install my new Eprad automations and just mount a Strong switching rectifier in the base. I don't have a lamphouse or projector pedestal and this will solve both of those problems and let me get up and running. My main question is will this work and will the lamphouse portion still work if I make this change to the rectifier? Are the lamphouse ignitor parts DC and therefore will they work with any rectifier since they run off of the output side of the rectifier which is a DC supply? Any thing that may cause major problems that anyone can forsee? Would I be better off buying a new console or base and lamphouse? Thanks.

Posted by Sean Weitzel (Member # 244) on 05-17-2011, 01:32 PM:

I too am interested. I acquired a CH-10 that has a 3 phase 3kw power supply stuffed into it.

Posted by Eric Robinson (Member # 2966) on 05-17-2011, 03:33 PM:

How about using one of these to convert your single phase to 3 phase?

Phase Converters - Wikipedia

"One method for using three-phase equipment on a single-phase supply is with a rotary phase converter, essentially a three-phase motor with special starting arrangements and power factor correction that produces balanced three-phase voltages. When properly designed, these rotary converters can allow satisfactory operation of three-phase equipment such as machine tools on a single-phase supply. In such a device, the energy storage is performed by the mechanical inertia (flywheel effect) of the rotating components. An external flywheel is sometimes found on one or both ends of the shaft."

3 HP Rotary Phase Converter for $285.00

I'd be worried about maxing out your single phase supply though. Are you going to try and run a 2K bulb?

Posted by Gordon McLeod (Member # 33) on 05-17-2011, 04:00 PM:

Phase convertors unless a true MG set will not work
SO take out the rectifier and install a strong switcher since it will run on both single or 3 phase
watch the grounding and insure that there is bypass caps on the ignitor

Posted by Joshua Waaland (Member # 287) on 05-17-2011, 05:37 PM:

I am aware of phase converters, but don't really like the idea of having three phase in my house. I use 230 460 & 575 3-phase at work all the time so I am well aware of the dangers and how to handle it. I just don't like using it if I don't have to at home. I had a 200 amp panel installed in my house so I am not worried about amperage draw on single phase.

Thanks for the tips guys. The manual for the console sucks. Not much in the way of drawings or info.

Posted by Sean Weitzel (Member # 244) on 05-17-2011, 06:23 PM:

I'm going to do just that and yank out the 3 phase guts and put this standalone christie 120v 1k rectifier in it's place. I'm only going to run a 1k bulb anyway.

Posted by Joshua Waaland (Member # 287) on 05-17-2011, 06:30 PM:

I am going to run a 2,000 watt bulb since that is what this console was built for...or so I read in the manual.

Posted by Louis Bornwasser (Member # 3063) on 05-17-2011, 09:25 PM:

Christie one phase 1000 watt are disasters(fire).

Try www(dot)perfect phase(dot) com. This is a solid state 1 phase to 3 phase device with nearly perfect power factor. Better and quieter than a rotary. Louis

Posted by Dave Macaulay (Member # 813) on 05-18-2011, 09:07 AM:

I think it's "phase perfect" not "perfect phase".
Possibly you could get a Strong switcher for free if you ask around at a cinema converting to digital. I have been offered complete working consoles if I'll just take them away. Why are projection rooms never on the same floor as a loading dock?
A 2kW phase converter is going to dent your wallet pretty severely.

Posted by Richard Hamilton (Member # 321) on 05-18-2011, 10:16 AM:

When I worked at Strong, they had piles of switchers sitting around, you could call them. Oh wait, my bad, those were all sent in for repair.
Nevermind,
Rick

Posted by Joshua Waaland (Member # 287) on 05-18-2011, 11:20 AM:

I would really like to just get a newer Strong or SLC series Christie console instead of messing around with this one. It's just finding one locally that's the problem.

Posted by Andres Briano (Member # 4621) on 05-24-2011, 11:23 AM:

quote: Dave Macaulay
Why are projection rooms never on the same floor as a loading dock?

quote: Joshua Waaland
I would really like to just get a newer Strong or SLC series Christie console instead of messing around with this one.

Why?? I would love that experiment! Focus on the learning and the satisfaction derived from it! Go ahead!! [beer]

Andrés

Posted by Jim Cassedy (Member # 4115) on 05-28-2011, 12:28 PM:

I know of one booth here in San Francisco where at some
point in history, a tech converted two Christie CH-20's
to run on single phase using a bank of huge hi voltage
capacitors across the incoming AC line to create the
"phantom phases", so to speak.

I was tempted to trace-out the circuit, but it's such
a shakey arrangment that I really don't want to get
too near it. It does work well however, and has been
doing so for over 10 years. The only 'problem'
(aside from numerous electrical code issues I'm
sure it violates by the sloppy way it was done)
is that the rectifiers now produce an extremely
irritating and very loud 120hz hum. I can't spend
more than a few minutes in that booth when those
things are turned on. I'm tempted to bring my
RTA with me next time I go there and measure
the noise level!

But other than that- - it works well!

Posted by Joshua Waaland (Member # 287) on 06-01-2011, 07:58 AM:

An Ohio dealer that I know told me he has a single phase rectifier that came from a CH10 that I can put into my console. He also told me that my console has the Phoenix Kit which does make it more desirable to hold onto. Besdies changing the rectifier and automation, this should be a pretty easy job. [Roll Eyes]

Those dumb automations are so integrated into the wiring that it may take a few weeks to accomplish that task.

Posted by Mark Gulbrandsen (Member # 72) on 06-02-2011, 08:58 AM:

LIke Louis says... be very careful as they all fail but I think that is a bit of an understatement... At a theater in Vernal, Utah I literally saw one shoot flames three feet out the back of the console! You'd probably be better off using a capacitor bank on what you already have to generate the third phase. Also with the Phoenix kit a medium size candle might give you sufficient light to get to 16 fl on a small screen although color temperature is bound to be a little warm [Smile]

Mark

Posted by Louis Bornwasser (Member # 3063) on 06-02-2011, 10:56 AM:

Every single phase Christie rectifier that I have ever seen required multiple wiring repairs in the primary, and eventual transformer replacement. All were 1000 watts. Each one drew 29 ampf at 126 volts. This is 3,654 watts to power a 1000 watt bulb, running at 45 amps. I never felt comfortable running above "LOW" due to the fires.

All were replaced with used IREM rectifiers, which are still functional 30 years later. Louis

Posted by Joshua Waaland (Member # 287) on 06-07-2011, 08:19 AM:

Wow! Maybe a phase converter is the way to go.

Welding power sources are basically a big rectifier also. They convert three phase AC power into DC power. The old transformer based welders were all three phase and any single phase units only provided low amperage for welding thin material. A few years ago inverter based technology was introduced to the welding market and inverter welders are much different. You can plug an inverter into any phase or voltage level and it automatically detects it and adjusts internally. They are also much smaller and much lighter since they do not contain a transfromer. However they do have a lot of electronics which are more prone to failure. Overall, they are great machines and you can do many different processes with them like MIG, Pulse MIG, Scratch Start TIG, Stick, etc, etc. The old transformer based machines only can do MIG at best. The new inverters are still somewhat limited in output amperage on single phase input, but they are better than the transformer based machines.

I am guessing that the Strong switching power supplies are the cinema industries version of an inverter welder?

On a separate note, I pulled the xenon bulb out of the lamphouse this morning and it had some black spots inside. The lamphouse support screws were all falling out and the whole internal aluminum lamphouse was leaning to the igniter side. The previous owner of this equipment that ran the theater was a really nice guy, but I could tell he had absoluetly no experience working with this kind of equipment. The bulbs were obviously never rotated or changed out, so I tossed them to prevent any future explosions in the lamphouse. Considering that the console is sitting in the garage (with no projector on it and the snood is open) where my son plays sometimes, I feel much better having gotten the bulb out. The previous owner removed the equipment and took it home with the bulbs still installed. [Eek!]

Like I said, he had no understanding of this equipment and how to handle it properly.

There were two consoles but one of them fell out of his trailer when he was transporting it home. It was smashed and the bulb ends were just hanging there and most of the top of the console was gone. I stripped it down and kept some spare parts from it, but the sheet metal and the transformer have been in the back of my truck for the past two weeks waiting to go to the scrap yard. I tried taking the transformer apart layer by layer, but that is taking forever. I brought it to work today to try and cut it with a torch or our metal saw to remove the copper. This is too much like work. [Wink]

Posted by Gordon McLeod (Member # 33) on 06-07-2011, 11:27 AM:

ORC used Miller welders as does Imax with a modified boost circuit