# Control/DimmingDMX relay for high-wattage fixtures?

#### Fennaloom

##### New Member
Hi:

Total newbie to this forum, with a question to the experts out there.

I have two sets of three 1500W quartz fixtures (i.e. 4500W per set), running off 220 or 240 V. I would like to be able to control them--on/off only--with a DMX relay, so that I can do this from my console rather than having a manual switch. Can anyone recommend a relay that can handle this kind of power need? I don't mind whether it's one relay for each set, or one relay for both sets. I have done some research online and within this forum, but can't find anything, so am turning to you for help.

Oh, and we use these for one week every year, so I'd prefer not to blow too much money on the things.

Thank you very much.

#### RickR

##### Well-Known Member
ETC https://www.etcconnect.com/Products/Power-Controls/ recently launched the Foundry series which includes single and 8 pack 20A relays. These are permenantly installed units and surprisingly inexpensive.

They also have a ColorSource relay, wired or wireless. Again 20A but can clamp on next to the fixture, though more expensive.

I'm sure there are less expensive options, but not by a lot.

(Don't use dimmers, but I think you knew that.)

RickR

#### JohnD

##### Well-Known Member
Fight Leukemia
Another possible option would be LYNTEC

EDIT: Oh, here is the Fullcompass price for an ETC foundry unit. UFR-2
EDIT2: Are these some sort of hard wired high bay fixtures or something like that? They are tungsten halogen and not HMI or something else.

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#### JonCarter

##### Well-Known Member
With the ever-increasing use of LED instruments which need constant clean 120V power, why haven't dimmer manufacturers come up with a dimmer module with a contactor which bypasses the solid state dimmer and provides the clean 120V to the output, controllable by the DMX dimmer control?

#### danTt

##### Well-Known Member
With the ever-increasing use of LED instruments which need constant clean 120V power, why haven't dimmer manufacturers come up with a dimmer module with a contactor which bypasses the solid state dimmer and provides the clean 120V to the output, controllable by the DMX dimmer control?
They have. ETC calls it a TP20 module. Strand probably calls it a PT20 module, given their recent creativity and innovativeness.

RonHebbard

#### JJBerman

##### Active Member
With the ever-increasing use of LED instruments which need constant clean 120V power, why haven't dimmer manufacturers come up with a dimmer module with a contactor which bypasses the solid state dimmer and provides the clean 120V to the output, controllable by the DMX dimmer control?
They have. ETC calls it a TP20 module. Strand probably calls it a PT20 module, given their recent creativity and innovativeness.
As danTt said, ETC has a ThruPower module which has dimmer and relay circuitry. They are TR20AF/TR20SAF. Not TP20.

ETC also has a relay series of modules; R20/R20AF, R15/R15AF. which are just relays.

#### cdub260

##### CBMod
CB Mods
This may be a bit overkill for your needs, but there are a few different companies out there that manufacture DMX controlled breaker panels. The advantage of this is that if you replace your existing panel with DMX controlled panel is that, depending on your current setup, you may be able to use your existing wiring and still gain the control you're looking for. The main disadvantage is that these panels are expensive.

#### Chase P.

##### Well-Known Member
Indu Electric makes several portable options, including a 48 channel, 20 amp (each, obviously), dmx controlled rack.

I so want to use one to do one of those over-the-top home holiday light displays. I wonder if my local power company would like to sponsor me by installing a 3 phase service for the holiday season?

RonHebbard

#### porkchop

I like the sounds of the UFR2, but another option that may provide you with more parts that are handy to have around for other projects is to break it up and have low current DMX relays trigger higher current standard relays. Blue Point Engineering sell a 4 and 8 channel DMX relay modules for $150 and$180 respectively. Those relays trigger the coil of a higher current ice cube relay (like this one) and you're off to the races. You can keep the ~$50 of ice cube relays as one assembly for this purpose and you have a nice multi-channel DMX relay module that you can use for other things the other 51 weeks out of the year. #### Chris Pflieger ##### Well-Known Member I like the sounds of the UFR2, but another option that may provide you with more parts that are handy to have around for other projects is to break it up and have low current DMX relays trigger higher current standard relays. Blue Point Engineering sell a 4 and 8 channel DMX relay modules for$150 and $180 respectively. Those relays trigger the coil of a higher current ice cube relay (like this one) and you're off to the races. You can keep the ~$50 of ice cube relays as one assembly for this purpose and you have a nice multi-channel DMX relay module that you can use for other things the other 51 weeks out of the year.
I did something like that because I could buy big, beefy three pole contactors and I wanted a rack mount solutions. That's how I replaced my dimmers when switching to LEDs.

The caveat is the final product isn't going to be UL listed, so your AHJ may balk. The only reason I undertook it is because my day job is designing lighting control panels and getting them UL listed, so I felt I'm more that qualified...

If I didn't need a rack mount solution for retrofit, I'd buy an "off the shelf solution".

YMMV.

For the OP's "one week out of the year", I'd go with ETC's ColorSource modules.

#### Fennaloom

##### New Member
Can you have 6 separate relays or do you have to have [email protected] or [email protected]? And they are 220v - each fixture?

I just can't quite picture the fixtures or more specifically what the power is.
No, I can't have six separate relays: each set of fixtures is combined on one power line. So: one power line has three fixtures on it, so does the other. I don't know the voltage of the fixtures, only the wattage. I'd prefer to have [email protected] rather than [email protected] because that way I can control them separately.

#### Fennaloom

##### New Member
ETC https://www.etcconnect.com/Products/Power-Controls/ recently launched the Foundry series which includes single and 8 pack 20A relays. These are permenantly installed units and surprisingly inexpensive.

They also have a ColorSource relay, wired or wireless. Again 20A but can clamp on next to the fixture, though more expensive.

I'm sure there are less expensive options, but not by a lot.

(Don't use dimmers, but I think you knew that.)
Thanks. I think I had looked at those, but I'm a bit nervous, because if my power is 220V (rather than 240V), then each set of three 1500W fixtures would draw (1500W x 3) / 220V = 20.5A, which is slightly above the rated current of these units. If I have 240V power, then each set of fixtures would draw (1500W x 3) / 240V = 18.75A, which should be fine. Maybe I should go test my mains voltage.

Yes, I won't try to use dimmers!

#### derekleffew

##### Resident Curmudgeon
Senior Team
Thanks. I think I had looked at those, but I'm a bit nervous, because if my power is 220V (rather than 240V), then each set of three 1500W fixtures would draw (1500W x 3) / 220V = 20.5A, which is slightly above the rated current of these units. If I have 240V power, then each set of fixtures would draw (1500W x 3) / 240V = 18.75A, which should be fine. Maybe I should go test my mains voltage.
With incandescent loads, the relationship between current draw and voltage is not as you think it is. One first needs to know the lamps' manufacturer-stated wattage at particular voltage, then one can apply the appropriate formula:
watts/WATTS = (volts/VOLTS)^1.6
(not 'squared' as you would get with a fixed resistance)

Essentially, more volts equals more watts, and less volts equals less watts.

-----

Back to your original question, I've used the Fleenor DMX relay http://www.dfd.com/1r20.html at 208V with L6-20 in & out, but I don't know if that use is approved by the manufacturer. @jfleenor ?
Warning! Not inexpensive! MSRP $514. Oh, and we use these for one week every year, so I'd prefer not to blow too much money on the things. I should have reread that part before suggesting Fleenor. As someone from Production Arts, who wasn't @STEVETERRY , used to say, "Yeah, we're not very good at that lowest bid contract thing." #### jfleenor ##### Well-Known Member Back to your original question, I've used the Fleenor DMX relay http://www.dfd.com/1r20.html at 208V with L6-20, but I don't know if that use is approved by the manufacturer. @jfleenor ? Warning! Not inexpensive! Yup. We have two versions, the DMX1REL20A, and the -2POLE version, which is specifically made to switch 208-240VAC. The data sheet and manual are NOW on our website. #### BillConnerFASTC ##### Well-Known Member Need to know lamp voltage but I suspect 20 amps is not going to cover 4500 watts. Let me repeat must you know lamp voltage of lamp. Find a contactor whose rating meets or exceeds the voltage and amperage; and pair it with a low voltage DMX relay. If - IF - it happens to be a 220 volt lamp - and there are quite a few at 1500 watts - you need a 30 or 40 amp 2 pole contactor for each circuit by my quick calculation. What DMX card or device you use to fire that I'll leave to others. The contactors in the$10 range at Home Depot are available with 24 volt and 120 volt coils. Could use the Fleenor device to drive the 120 volt coil but I suspect there are more economical choices for a once a year event.

But you really need more data on the loads. Sorry. You could be on the verge of disaster not knowing those answers.

#### RickR

##### Well-Known Member
Filaments are resistors. Granted resistance changes with extreme temperature changes, but it's ignorable. So amperage and voltage directly related and quite apart from wattage. Afterall we dim by lowering the voltage!