Depends upon the
dimmer manufacturer and
mirror ball motor.
Sometimes like on a Sensor rack, you can swap cards for a on/off
switch to replace the
dimmer. Otherwise and as a good
point, depending upon the
dimmer, the
trim setting
voltage at zero or 100%could be possible to cause problems with the motor of the
mirror ball motor, used as a
switch or not, if not it's chopped sinwave and
lag causing damage.
I take it for granted there is no way to
hot patch channels and use if necessary a
breaker on the
hot patch circuit to turn it on or off without the
power coming from a
dimmer module.
Most
dimmer manuals say not to run
power tools off a
dimmer. Not good for motor or
dimmer.
On the other
hand, somtimes it will cause no problems at all in the motor and if the
dimmer is large enough and quality, no noticable damage in it's limited use. Done it before without a problem, but it depends upon the brand of
mirror ball motor.
Remember that most dimmers will be trimmed so that they have a lamp warming
current on the lamps. This means that even at 0%, there is still say 7 to 20 volts going to the lamp in warming the
filament. Depending upon the
mirror ball motor
power, it might not be enough to recieve this
voltage because normally it takes 75 volts to get the warming
current - thus the
ghost load. On the other
hand, who knows if it would or not in that warming
current not being enough to spin the motor at full speed but it's
current being there still in melting down the motor.
Should
call the manufacturer of the
mirror ball motor and ask. They no doubt will know their product and have come across this problem before.
Don't know if they are in Europe but in the US View-Mor
http://www.vue-more.com makes a
mirror ball motor that does not seem to have problems even being dimmed by a
dimmer - linear or electronic. Good beefy motors for the 24" to 48" size mirror balls.
Another option would I recommend would be to use one of the new American DJ
DMX mirror ball motors. Believe it or not, they are very substantial in quality. Though I do have two out of six that might or might not be working after a tour in my repair pile. This way you can put the
dimmer on at full, adjust it's
trim for full
voltage, and
switch on and off the
mirror ball motor, reverse or dim it by way of a
DMX channel. That's I believe part of the design intent. Good design though we have two our electronics department in doing this, came up with years before in concept. This given American DJ has a 240v version as they probably do.
Other things to do or check on the
mirror ball motor. Unless running a 8"
mirror ball, you should ensure the
mirror ball motor has a slip gear so once it's powered off, the
mirror ball won't damage the motor as it continues to spin.
Also if it's using a key ring to hold the load, remove it and replace it with a 1/16"
wire rope and
nicopress sleeve so there is no chance that should the
mirror ball get hit, it will fall.
Finally, most
mirror ball frames are cast aluminum and on larger mirror balls, them holding the weight of the
mirror ball - given it's designed to hold that size in the first place, needs all of it's mounting flanges in use to properly support the load. Use only two out of the four mounting flanges and the frame could crack. If using a cheap
mirror ball motor that really does not have much of a means for mounting, it should also get a similar amount of mounting bolts applied to it in mounting to a sub-frame it hangs from. Drywall screws to a
block of plywood should be sufficient if only a 8"
mirror ball, otherwise
thru bolting would be necessary, if not steel plate dependant upon the size of
mirror ball.
A better concept is to bridge all four mounting flanges or holes so each provides equal support, and in addition to this provide a means of mounting a clamp or suspension ring in addition to
safety cable.
Could be as simple as a overly large plate sufficient in
thickness that it won't
bend once bolted to the flanges holding the weight. Cr create a form of marionette like I-shaped bridge of
unistrut or box steel so you have clearance for a clamp to
bolt to the bridge and ability to tie both bars together into a single one. Use of two Clamps where possible as spaced out as possible to prevent torque from causing a problem a single clamp might have problems with.
Otherwise at very least if suspended, use four
safety cables since they are assumed to be the same length, and link them to a ring at the center for suspension - given a forged eye-bolt can't be made to mount on the above box I-frame. What ever is used, make sure also that screws in and about the
mirror ball motor are tight, and those mounting it also can't come loose from vibration.