Film-Tech Forum ARCHIVE: Projector Motor Power Consumption

This is topic Projector Motor Power Consumption in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Lyle Romer (Member # 1266) on 04-10-2009, 08:31 AM:

I'm working on an electrical use study and I'm trying to get an accurate representation of the power used by a projection booth setup. I assume the lamp uses FAR more power than the projector motor but I want to include the motor's power consumption for accuracy. Does anybody know the typical power consumption of a projector motor? I can't find it in the manuals. The specific projectors in use are Centurys but I'm guessing that most projector motors would consume approximately the same power.

Posted by Tony Bandiera Jr (Member # 2365) on 04-10-2009, 02:04 PM:

Lyle,

You can figure on about 3-4 amps per projector motor and be safe. Some run at a lower amperage and all have a peak starting current several times running current (it only lasts a second or two and is not significant to power calcs).

The actual running amps of identical make projector will vary slightly depending on the friction of the projector's gears, etc. and whether or not film is actually in the machine. [Smile]

Posted by Gordon McLeod (Member # 33) on 04-10-2009, 02:39 PM:

Be aware that most electrical codes will require service and panel sizing based on breaker loading.
One is wise to have a seperate breaker for the motor so if it fails and trips the breaker it doesn't kill anything else
typicaly we size smaller theatres with 2K xenons as
1 15amp motor
1 15 amp platter
1 15 amp automation
2 20amp dimmers
1 15amp processors/digital (UPS feeding them
6 15 amplifiers
1 3 pole 30 amp rectifier
1 15 amp lamphouse
1 15amp cleaning lights
1 15amp booth lights
2 15amp raceway outlets
1 15amp booth outlets

the total cannot in many locations exceed 80% of the feeder size so that would mean approx 150amp per phase feed

Posted by David Zylstra (Member # 4230) on 04-10-2009, 02:55 PM:

My measurements of a late model 35mm Christie set up is:
Fans(120v)only (at rest between shows) - 2.4 amps
Motor running (with above fans) - 6.7 amps (so net motor is 4.3 amps)
Lamp PS (3 ph) - 33.93amps ave per leg

If you are interested in digital (early Christie CP2000H):
DLP engine - 2.7 amps (208v same when showing picture or between shows)
Fans - 1.2 amps (fans are 208v and run constantly)
Lamp PS (3ph) - 34.3amps (ave per leg)
Screen server - 1.7amps (on 24/7)
TMS rack - 9.8amps (on 24/7)

Both lamphouses measured were running CXL-60 lamps and I forget what the lamp wattage was on each.

Posted by Gordon Bachlund (Member # 124) on 04-10-2009, 03:17 PM:

Gordon's circuit loads are conservative and safe.

Be advised that most motors have nameplates as required by Code and industry practice that provide the information you are looking for.

Posted by Jason Burroughs (Member # 68) on 04-10-2009, 04:08 PM:

Keep in mind, breakers should be de-rated by 20% when factoring what size breaker should be sized for a given load.

A 30Amp breaker should be sized to equipment that has a 24Amp Load.

Also its good to make sure that you don't have major inductive loads on the same branch as a resistive load.

Breakers below 600Amps are not "continuous duty"

A good electrician should be able to size breaker and wire sizes appropriately for you.

Posted by John Hawkinson (Member # 1135) on 04-10-2009, 07:59 PM:

Waitasec.
Lyle, are you asking about this for purposes of sizing wires, breakers, etc.? Or are you asking for purposes of estimating the cost to run booth in monthly utility charges?

Those two questions have very different answers, and you've gotten a mix of the two. The peak values are really important for somethings, but not so much for other things.

--jhawk

Posted by David Zylstra (Member # 4230) on 04-10-2009, 08:52 PM:

quote: Lyle Romer
I'm working on an electrical use study

This first statement led me to beleive the idea is to estimate the cost of running the equipment.

Posted by Tony Bandiera Jr (Member # 2365) on 04-10-2009, 08:58 PM:

That's what I thought too... but the others are on the right track in regards to Code issues and good design practice. [Smile]