OC with 50% instead of off

[electrofelon]

I have a stairwell with a three way switch at the top and bottom. I have a requirement that the lights remain on at 50% after timeout, and come back to 100% when occupancy is sensed. IS there a wall control that will do this? I talked to Lutron and they have a remote dimming module that would work with their wireless OC sensors, but it is 0-10 dimming only which I do not have.

I am thinking I could "make my own" by using a dimmer and an OC sensor with the OC connected in parallel on the load side of the dimmer. Am I thinking about this right?

 

[LarryFine]

Use incandescent bulbs and wire a diode between the travelers.

Oh, you need OC. My idea still might work.

 

[synchro]

I have a stairwell with a three way switch at the top and bottom. I have a requirement that the lights remain on at 50% after timeout, and come back to 100% when occupancy is sensed. IS there a wall control that will do this? ...

I am thinking I could "make my own" by using a dimmer and an OC sensor with the OC connected in parallel on the load side of the dimmer. Am I thinking about this right?

I believe that might work. So if I understand your requirements, you'd have the dimmer and two OC sensors (one OC at the top and one at the bottom) all connected to the line side, and all of their outputs would be connected together and to the load.

I think the Lutron LOS-SIR type OC sensors would have a better chance of working than some others because there's no minimum load requirement, whereas Maestro for example needs at least a 40W load. If the dimmer is already providing an output to provide a 50% light level, then that takes some loading away from the OC sensor if it's activated, and perhaps that could be a problem if the OC has a minimum load requirement.
So I assume the setup in your case would be OC sensors at both the top and bottom locations, and a dimmer at one of the locations (or somewhere else).

http://site.electricsuppliesonline.com/documents/Lutron/los-sir-inst.pdf

https://www.lutron.com/TechnicalDocumentLibrary/Spec%20Guide%20Volume%201%20Sensors.pdf

https://www.platt.com/CutSheets/Lutron/98328_Spec1.pdf

 

[kwired]

What do you have for luminaires?

Old school linear fluorescent (or even ones converted to LED tubes) you maybe just wire one ballast in each luminaire so it is always on and switch the other ballast with occupancy sensor.
If you have LED luminaires you maybe only have one driver per luminaire though. If no 0-10V are they dimmable?

 

[petersonra]

Wire half the lamps so they are on all the time and the other lamps on the occupancy sensor.

 

[kwired]

Wire half the lamps so they are on all the time and the other lamps on the occupancy sensor.

This is in a stairwell, so may or may not work depending on what he has to work with. If only one luminaire at each level you maybe can't connect half at each level to different switching schemes. Old school troffers with two ballasts each you could though.

 

[James L]

Relay?
Connect the light the common

Power the dimmer and connect the load side to the normally closed contact.

Power the occupancy sensor and connect the load side to the normally open contact and the coil

 

[Bogdan-PDX]

Looked for specs and it’s 120VAC

Best would be 120VAC Lutron dimmer
Maestro Occupancy/Vacancy Sensor C•L Dimmer

Dimmer-models >>> MSCL-OP153M; MSCL-OP153MH; MSCL-VP153M; MSCL-VP153MH

And if your load is more then the OC can candle then you would need and Power model similar to this Lutron

LUT PHPMPA120WH PWR MOD PH


And if you do go with power Model, then make sure your dimmerOC switch is compatible with it.


I recently used couple power modules on recessed luminaries of 174count. Loaded it to 15Amp each. And dimming was spectacular.

Good luck.

 

[winnie]

Instead of dimming all the lights, have the oc switch half of them.

Jon

 

[electrofelon]

Thanks for the replies. Switching half the lamps/fixtures is a clever simple solution, but unfortunately would not work with the current set up. These energy code requirements are clearly much easier to comply with if you design around them aren't figuring it out at finish.

Based on the results of my other occupancy sensor thread, it seems like the dimmer set at 50 percent plus the two OS's with their loads all connected together would work.

 

[d0nut]

There are several manufacturers that make stairwell lights with integral occupancy sensors that meet this 50% minimum requirement. I would suggest replacing the lights with some of those and eliminating the 3-way switching.

 

[hillbilly1]

Thanks for the replies. Switching half the lamps/fixtures is a clever simple solution, but unfortunately would not work with the current set up. These energy code requirements are clearly much easier to comply with if you design around them aren't figuring it out at finish.

Based on the results of my other occupancy sensor thread, it seems like the dimmer set at 50 percent plus the two OS's with their loads all connected together would work.

Should work, you are just shunting the dimmer with the OC contacts.

 

[Kansas Mountain]

What type of dimming protocol do you need? Lutron does now have phase dimming powpaks, not just 0-10V.

Phase Dimming Powpak - https://www.lutron.com/TechnicalDocumentLibrary/3691150.pdf
Wireless Wall Sensors - https://www.lutron.com/TechnicalDocumentLibrary/Spec_Sheet_369481a_ENG.pdf

You won't be able to program the fixtures to only go down to 50% unless you add a Hub though, or unless you reprogram or reorder the drivers so they never go below 50%.

 

[Flicker Index]

You can use a step dimming ballast in which you apply power to L1 to light to a certain level, then apply power to L2 to get another level and apply power to both L1 and L2 to get full brightness. So you'd keep L1 always on, then feed L2 through motion sensor which could be mounted inside the fixture to avoid running a second hot.