Novice lighting question. We have some Chauvet PROD6 dimmers. We want to run them at 208V. If we run them at that voltage, we get 208V at the dimmer outlets and it quickly pops a 120V lamp. I assume that this is normal. If not, I can repair them. I am guessing that professional dimmers do not have this problem. Any advice you have is appreciated....and feel free to take shots at this very knowledgeable sound guy who is building on his lighting knowledge.
208V Dimmer
- Thread starterAccutrack
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Crisp image
Well-Known Member
Or connect them in series using a safe method.
Why? What situation are you in that this is the solution you came up with? You're asking us to solve your solution, and not your problem.
This seems like a can of worms completely worth avoiding.
I don't think there's a 'safe method' to wire up two 120v lamps in series to run on a 208v dimmer (which would just get you probably-disappointingly dim lamps).
For OP - You've got a very weird dimmer pack, but as others have said, you won't be able to use 120v lamps on a 208v service.
So, looking closer at this awful horrible invention by chauvet (Really, @Ford? How does something like this get listed? Some unpredictable voltage on nema 5-15 outlets, and apparently requires both 120v Line-Neutral and 230v line-neutral for the dual voltages simultaneously to work properly)?
I think your best bet is 120in-120 out. Anything else is going to be using Nema5-15 receptacles for things that it's not rated to do. If you absolutely must use this product and use a 230v source, you could look at finding 230v lamps instead. Otherwise, your best bet is going to be to feed it with 120, either via a transformer or via the wall.
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JChenault
Well-Known Member
The fact that the OP is talking about 208 volts makes me think he is dealing with a 'Wild Leg' situation. IE a three phase power where one the hot to neutral is 120 volts for two of the legs, and 208 volts for the third leg. This type of feed is sometimes used for motors. You can use the two 120 volt legs for dimmers, but using the 208V leg is asking for trouble.
Virtually all theatrical dimmers take the input voltage and reduce that voltage on output. IE if you have 120 volts available at the dimmer, at 100% you will get (almost) 120 volts out ( there is a bit lost due to inefficiencies). So connecting up a 208 Volt power supply to the dimmer can blow out any 120 volt lamps you connect to it when you run the dimmer up.
Things you can do to fix this:
1 - don't use the 208 volt leg. ( best solution)
2 - You might be able to get a transformer to convert 208 volts to 120 ( if you could find a couple of auto-transformre dimmers ( sometimes called a variac) that were rated for 20 amps - you could use those to reduce the voltage from 208 to 120 ( untill someone comes along and truns the variac up - causing all you lamps to blow)
3 - purchase a transformer to convert 208 to 110 or 120. You will need one for each input line. Granger has some for around $900 each.
As to the dimmer pack. It makes sense to me for a manufacturer to provide a small dimmer pack like this that would operate on either 120 or 240 volts ( the market is bigger than just the US). A small dimmer pack like this, designed to be for the lower end market where you can just plug the unit in typically has two cords so it has enough power to drive all 6 dimmers ( IE three per circuit).
Looking at the manual, the input power cords is a type that will handle 20 amp 120 or 240 power. The manual says that both input lines need to be on "The same electrical phase" This seems extremely problematic to me. How to you know what phase two separate 20 amp circuits are on? I also don't understand how you can use a Nema 5-15 outlet for 120 volts.
There is the ability to limit the output of a dimmer by setting a 'max level' I have no idea if that is proportional ( IE if you set the max to 50% and set the fader to 50% would you get 50% output or 25% output).
I expect that some sales guy realized that 'Oh - the two sets of power circuits are independent so the user could have different voltage on the two cords. Lets put that as an advantage. I believe that using it in this way is probably "dumber than dirt".
( I do not know any more about the dimmer pack than a quick read on the web )
Virtually all theatrical dimmers take the input voltage and reduce that voltage on output. IE if you have 120 volts available at the dimmer, at 100% you will get (almost) 120 volts out ( there is a bit lost due to inefficiencies). So connecting up a 208 Volt power supply to the dimmer can blow out any 120 volt lamps you connect to it when you run the dimmer up.
Things you can do to fix this:
1 - don't use the 208 volt leg. ( best solution)
2 - You might be able to get a transformer to convert 208 volts to 120 ( if you could find a couple of auto-transformre dimmers ( sometimes called a variac) that were rated for 20 amps - you could use those to reduce the voltage from 208 to 120 ( untill someone comes along and truns the variac up - causing all you lamps to blow)
3 - purchase a transformer to convert 208 to 110 or 120. You will need one for each input line. Granger has some for around $900 each.
As to the dimmer pack. It makes sense to me for a manufacturer to provide a small dimmer pack like this that would operate on either 120 or 240 volts ( the market is bigger than just the US). A small dimmer pack like this, designed to be for the lower end market where you can just plug the unit in typically has two cords so it has enough power to drive all 6 dimmers ( IE three per circuit).
Looking at the manual, the input power cords is a type that will handle 20 amp 120 or 240 power. The manual says that both input lines need to be on "The same electrical phase" This seems extremely problematic to me. How to you know what phase two separate 20 amp circuits are on? I also don't understand how you can use a Nema 5-15 outlet for 120 volts.
There is the ability to limit the output of a dimmer by setting a 'max level' I have no idea if that is proportional ( IE if you set the max to 50% and set the fader to 50% would you get 50% output or 25% output).
I expect that some sales guy realized that 'Oh - the two sets of power circuits are independent so the user could have different voltage on the two cords. Lets put that as an advantage. I believe that using it in this way is probably "dumber than dirt".
( I do not know any more about the dimmer pack than a quick read on the web )
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Crisp image
Well-Known Member
I have seen this done here in Australia simply because the lamps coming from the USA were 110v. The safe way is to do it inside a sealed junction box and have it clearly labelled as to what it does.
I had the same thought reading that manual. The manual calls for two circuits on the same phase, and then also says you can use multiple input voltages simultaneously. I can't think of a practical use-case for that nor does it seem remotely like a good idea.
And if you have 220V coming into that pack and then have 5-15R's for the connectors, that seems like a bad idea.
The short answer is that it doesn't. I can not find any listing or recognition in the documentation.
STEVETERRY
Well-Known Member
What we seem to be forgetting in this thread: A 208V dimmer in North America is just not functionally the same as a 240V dimmer in the rest of the world.
Why?
Because a 208V dimmer in North America (even if you could find a reason to need one--which is dubious--please find me a 208V tungsten lamp) has both sides of the output 120V above ground. This requires it to be fed by a 2-pole circuit breaker.
ST
JChenault
Well-Known Member
Wandering further from the thread.
Steve. I don’t understand your comment re the 120 volt above ground.
I totally agree that using a 208 volt service for a dimmer makes no sense. however I can get 208 volts between the wild leg and neutral, and 120 between the other two legs and neutral. is there an issue with using the two 120 volt lega and ignoring the wild leg, and/or in using a transformer to convert 208 to 120?
thanks
STEVETERRY
Well-Known Member
STEVETERRY
Well-Known Member
In a 208V wye setup, both phases in a 208V single phase connection are at 120V with respect to ground. This makes them both "ungrounded conductors", each of which requires overcurrent protection. Likewise, if you just use L1 and L2 on a high-leg delta service to feed a 240V load, both L1 and L2 need overcurrent protection--hence the 2-pole breaker requirement. Only when a circuit has a grounded neutral conductor do you get to use a single-pole breaker to feed it.
ST
ST
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