Control/Dimming Replace analog relay switch with DMX relay

manthano

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I believe I have read most of the threads about controlling house lights with a DMX relay, but my situation is (I think) a little different than the ones I've seen on here. I'm in a gymnasium type building with several banks of high bay house lights. In my booth, I have an analog switch (actually a timer switch https://www.intermatic.com/en/in-wall-controls/spring-wound-countdown-timers/ff60mc ) connected to a relay that I can use to turn the house lights off (they will turn back on when the timer runs out). From what I can tell this timer is just breaking the "hot" leg of the relay circuit, similar to a basic analog light switch. Rather than having to manually turn this timer switch, I'd like to turn off the house lights via DMX. What kind of DMX relay do I need to open and close the hot leg of an existing analog relay? I have a licensed electrician that can hook this up, but what do I need to communicate to him?
 
Sounds like a job for ETC's UFR2 DMX Relay.
ETCUFR2.jpg
 
I believe I have read most of the threads about controlling house lights with a DMX relay, but my situation is (I think) a little different than the ones I've seen on here. I'm in a gymnasium type building with several banks of high bay house lights. In my booth, I have an analog switch (actually a timer switch https://www.intermatic.com/en/in-wall-controls/spring-wound-countdown-timers/ff60mc ) connected to a relay that I can use to turn the house lights off (they will turn back on when the timer runs out). From what I can tell this timer is just breaking the "hot" leg of the relay circuit, similar to a basic analog light switch. Rather than having to manually turn this timer switch, I'd like to turn off the house lights via DMX. What kind of DMX relay do I need to open and close the hot leg of an existing analog relay? I have a licensed electrician that can hook this up, but what do I need to communicate to him?
Calling @jfleenor I'm sure you and your family can make this easy for new poster @manthano and his fully licensed Installation and Maintenance Electrician or Master Electrician.
Toodleoo!
Ron Hebbard
 
Just about any old relay should work for this duty; It's a low(ish) power pilot/control circuit, probably 120V but that's not guaranteed by any stretch of the imagination. It should be easily possible to keep the existing switch and have an additional relay to control it when the lighting board is present, or to add a plug of some sort in parallel with the existing switch that you could connect a DMX relay box to when you need DMX control and unplug to keep things the same way they've always been. Getting one that's properly approved to integrate into the building electrical system is of course a very good idea.

Take care to ensure that whatever DMX relay thingy you choose can be set to default to turn the lights on in the event of DMX data failure; otherwise, if you or someone else unplugs the console without remembering to turn the house lights back on first, you'd be stuck without light and not make friends with the powers that be.
 
Thanks all. Maybe I'm misunderstanding something, but I don't think ETC's UFR2 or something like a Doug Fleenor DMX1REL20A will work in this application. If I understand correctly those units switch the power on/off from the power source wired or plugged into those units to their "load." I think I essentially just want to open a closed circuit, not supply power to a load. Right?

I should have made more clear as well that the timer switch in my booth is "soft of" wired 3-way, but not exactly. There's another switch to turn the lights on elsewhere in the building, but if that switch isn't turned on, my timer switch cannot turn the lights on. It can only turn them off for the duration of the timer.

@DrewE , do you have a recommendation for "any old relay"?
 
I don't have any specific good recommendations. DMX512 controlled relays are not too hard to find, but many of them seem to be of dubious origin for use in a hardwired situation.

Based on online datasheets and such the Pathway Connectivity 1003 looks really nice, but is very much overkill for what you need (twelve channels, rather than just one) and costs a pretty penny. Vellman makes a kit that would do the trick very nicely, but an assembled kit is presumably not going to be UL approved, etc.
 
When you say
several banks of high bay house lights
have you calculated the total load and know voltage? Could the timer switch (which I would say is in series not like a 3-way) be already switching relay controlled loads? Putting banks of lights in a gym on relays was common, unless it's a really small gym. Calculate the loads and voltage - some of the products mentioned might not be suitable.

BTW are they incandescent of discharge sources?
 
I don't have the load and voltage off the top of my head, but here's what I know... My electrician told me that each bank of lights is on a separate 50amp contactor with a 120v coil. Each contactor is controlled by a light switch. There is also a relay (between?) the switches that controls all the contactors. I believe my timer switch controls that relay.

The lights are actually LED but they used to be discharge. They replaced the lights with LED a couple years ago, but didn't change any of the wiring or controls beyond. I know the load is significantly less now that it's LED, but I don't know the exact numbers. I'll see if I can figure that out.
 
The actual load of the lights is immaterial for your particular use, since your switch (or relay if its replaced) is not directly interrupting their current. You just need to be able to switch sufficient current for the relay(s)/contactor(s) you are controlling, which should be pretty modest. I might be tempted to pull the wall plate off for the timer switch and measure the current with a clamp-on ammeter; that should also tell you if the switch is normally open or normally closed, which would be handy to know.
 
They are probably not latching, from what I could suss out from Google; also, I don't think I've seen any spring-wound mechanical timer switches that have momentary/pulse outputs, so a latching solenoid would not be a good match there. It seemed that there may have been various coils (with different voltage ratings) available. It should be quite simple (in concept, though one should be careful not to short things out etc.) to meter at the timer switch to determine voltage, if the contactor itself is at an inaccessible location.
 
I agree Drew - just hard to be sure sitting at my desk. I assume 24 volts holds contactors closed. I have no idea if acceptable to use a 120 v dmx relay to handle 24 volt or not, but sure would be simple and relatively inexpensive. Otherwise put the low voltage transformer on the relay assuming you want to control everything using the 24 volts. It will disable ant other switching though and you would have to leave the relay closed for other switching to ever work. Probably more elegant solutions. Along with contactor details of the LED retrofit lamp would be perhaps useful. The typical "corn cob" LED retro lamp usually is not dimmable; and I don't know inrush but suspect high.
 

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