Question for installing m/c cable with dimmer wires.

[pvannoy]

I've been an electrician for a few years now, but this is my first job with lighting controls. I am installing lights with 3 way dimmers and occupancy sensors. I am installing 12/3 MC with the little pink and purple dimmer control wires. My question is, do I need to run the dimmer control wire up to the fixture as well? Or do I need to run it up into the ceiling area for a power pack? Or just between the 3 way switches works just fine? I'm the JW on this job working by myself and others I've asked haven't given me an exact answer.

Thanks in advance for your help.

 

[tom baker]

And you are welcome. Great question by the way

 

[ActionDave]

The pink and purple are dimmer wires and need to come off the dimmer and up to the fixtures. The power packs will depend on what kind of switches you have, line voltage or low voltage and if you have ceiling sensors.

 

[pvannoy]

So if I have 3 way switches, do I need the pink and purple between switches as well?

 

[ActionDave]

The pink and purple are 0-10V dimming wires, they don't have anything to do with switching. You would want a set everywhere you have a dimmer.

 

[pvannoy]

The pink and purple are 0-10V dimming wires, they don't have anything to do with switching. You would want a set everywhere you have a dimmer.

Thank you. So normal 12/3 between 3 ways and the dimming wires up to fixture. Got it.

 

[Little Bill]

You will need 0-10 dimmers.

 

[Strathead]

With the various components of the question you ask, you have three separate "systems" and you should think of each separately.

First you have the lighting circuit. Hot, neutral, switches, etc. I assume you are well versed in that, including three way, four way switches etc.

Second you have the lighting control system. Think of this as independent of the above. You usually have a power pack, which takes line voltage (doesn't need to be the same circuit as the lights but usually is). The power pack contains a relay that will interrupt power in the switch leg from the above, just before it enters the first light fixture. All the rest is independent and is usually low voltage wiring running to occupancy sensors, daylight sensors, photocells and/or low voltage switches, etc. Note that this is one basic way it it done, this can have many different configurations.

Third is you 0-10V dimming. There are two different types of 0-10v dimming source and sink. In source the 0-10V is generated from the dimmer "switch". In sink the 0-10v is generated by each and every driver. Most of us will be working on current sink systems, so I will address those. Remember this is all independent of the above systems. Each driver provides approximately 0-10V. They all get hooked up in parallel with each other with the purple and pink wires. When the two wires are shorted together, it "sinks" the voltage and all the lights go dim. This system is a loop of the purple and the grey through all of the dimmed lights and the dimmer on the dimming circuit, so you can have more than one lighting circuit or switch leg (this is a closed system it only connects to the drivers and the dimmer). For example, you can have lights fed from both the normal and emergency systems in a room all controlled from the same dimmer. The 0-10V generated by each driver is a class II power source. So, it is run with separation from the power wiring. It can be reclassified per Article 700 of the NEC as class I and technically you have to go to every driver and black out the reference to a class II power supply, but thankfully, I have yet to see an inspector look for or require this. I am not going to go in the the class I class II further. Read else where in this forum if you want to know more.

Hope this helps.

 

[pvannoy]

With the various components of the question you ask, you have three separate "systems" and you should think of each separately.

First you have the lighting circuit. Hot, neutral, switches, etc. I assume you are well versed in that, including three way, four way switches etc.

Second you have the lighting control system. Think of this as independent of the above. You usually have a power pack, which takes line voltage (doesn't need to be the same circuit as the lights but usually is). The power pack contains a relay that will interrupt power in the switch leg from the above, just before it enters the first light fixture. All the rest is independent and is usually low voltage wiring running to occupancy sensors, daylight sensors, photocells and/or low voltage switches, etc. Note that this is one basic way it it done, this can have many different configurations.

Third is you 0-10V dimming. There are two different types of 0-10v dimming source and sink. In source the 0-10V is generated from the dimmer "switch". In sink the 0-10v is generated by each and every driver. Most of us will be working on current sink systems, so I will address those. Remember this is all independent of the above systems. Each driver provides approximately 0-10V. They all get hooked up in parallel with each other with the purple and pink wires. When the two wires are shorted together, it "sinks" the voltage and all the lights go dim. This system is a loop of the purple and the grey through all of the dimmed lights and the dimmer on the dimming circuit, so you can have more than one lighting circuit or switch leg (this is a closed system it only connects to the drivers and the dimmer). For example, you can have lights fed from both the normal and emergency systems in a room all controlled from the same dimmer. The 0-10V generated by each driver is a class II power source. So, it is run with separation from the power wiring. It can be reclassified per Article 700 of the NEC as class I and technically you have to go to every driver and black out the reference to a class II power supply, but thankfully, I have yet to see an inspector look for or require this. I am not going to go in the the class I class II further. Read else where in this forum if you want to know more.

Hope this helps.

This does help some. And I do understand normal switch power, 3 ways and four ways. But this is my first time with a firm of lighting controls.

Thank you

 

[Strathead]

This does help some. And I do understand normal switch power, 3 ways and four ways. But this is my first time with a firm of lighting controls.

Thank you

The luminary MC was hard for me to get my head around at first. Especially in regards to using it when separating the 0-10 as class II. Honestly, we install the dimming in the power conduit as class I 99% of the time. with all the time we have been dealing with it, the supply industry still hasn't made the components user friendly. For example, a couple jobs ago I received the wall dimmers by Acuity Sensorswitch. They had a tag on the pigtails stating "CLASS I WIRING ONLY" luckily, we had already installed it that way. I even went back to double check. There was certainly no mention of that in the submittal information, and if I recall it also wasn't in the installation instructions.

 

[pvannoy]

So is the luminary MC considered Class II? Since it's in the same jacket? Or does the spattered separate insulation jacket around the control wires allow for it to be considered a Class I?

Also, from what I read above, can I get away with a normal 12/2 from the switch up to the power pack, and then just a whip with the luminary MC from the power pack to the fixture?

 

[pvannoy]

I'm looking into classes locally for lighting controls, I want to get a full understanding of this as I feel ill be doing more of it, especially with all the Title 24 stuff here in California

 

[Strathead]

So is the luminary MC considered Class II? Since it's in the same jacket? Or does the spattered separate insulation jacket around the control wires allow for it to be considered a Class I?

Also, from what I read above, can I get away with a normal 12/2 from the switch up to the power pack, and then just a whip with the luminary MC from the power pack to the fixture?

Since we tend to try to speak very specifically here, the cable containing the purple and gray in Luminary MC is acceptable for class II wiring. Once the blue jacket is removed the individual wires must have separation in compliance with article 725. Class I is basically wiring that can be run with power and lighting, so hot neutral purple and gray in the same conduit is class one wiring.

Question 2 depends on your lighting control system and another code. First, where is your dimmer? It is usually part of the switch, so it will require the purple and gray. Purple and gray connect each fixture driver and the dimmer together, period. BUT don't forget new code required the neutral at the switch location in most cases.

 

[Cranky Oldguy]

With the various components of the question you ask, you have three separate "systems" and you should think of each separately.

First you have the lighting circuit. Hot, neutral, switches, etc. I assume you are well versed in that, including three way, four way switches etc.

Second you have the lighting control system. Think of this as independent of the above. You usually have a power pack, which takes line voltage (doesn't need to be the same circuit as the lights but usually is). The power pack contains a relay that will interrupt power in the switch leg from the above, just before it enters the first light fixture. All the rest is independent and is usually low voltage wiring running to occupancy sensors, daylight sensors, photocells and/or low voltage switches, etc. Note that this is one basic way it it done, this can have many different configurations.

Third is you 0-10V dimming. There are two different types of 0-10v dimming source and sink. In source the 0-10V is generated from the dimmer "switch". In sink the 0-10v is generated by each and every driver. Most of us will be working on current sink systems, so I will address those. Remember this is all independent of the above systems. Each driver provides approximately 0-10V. They all get hooked up in parallel with each other with the purple and pink wires. When the two wires are shorted together, it "sinks" the voltage and all the lights go dim. This system is a loop of the purple and the grey through all of the dimmed lights and the dimmer on the dimming circuit, so you can have more than one lighting circuit or switch leg (this is a closed system it only connects to the drivers and the dimmer). For example, you can have lights fed from both the normal and emergency systems in a room all controlled from the same dimmer. The 0-10V generated by each driver is a class II power source. So, it is run with separation from the power wiring. It can be reclassified per Article 700 of the NEC as class I and technically you have to go to every driver and black out the reference to a class II power supply, but thankfully, I have yet to see an inspector look for or require this. I am not going to go in the the class I class II further. Read else where in this forum if you want to know more.

Hope this helps.

"you can have lights fed from both the normal and emergency systems in a room all controlled from the same dimmer"- yes & no. Typically you'll need a way to force the emergency lights on at full brightness during power outages. That means running the control wiring to the emergency lights through a UL-listed interface with a normal power input. When the normal power fails, the interface opens the control loop, and all the emergency lights see a 10V signal- full brightness. It's the same way you need a bypass on the switch leg, to force emergency lights on whenever there's a power outage, regardless of switch position.