CMB16D Shared Commons?

[DocBrown86]

I am running 6, 12V DC white flood lights off of one bank of this controller. My distance from controller to the lights is going across the driveway, so I'm trying to run as little cabling as possible across that. I would like to split the 6 lights into 2 groups, and share a common wire (one common wire between 3 lights, and another for the other 3) with a positive wire separate per light.

In doing this, I would daisy chain the commons at the lights, and again at the controller, with the initial common going to channels 1 and 4. And as I said, each light would have its own positive with its own channel.

Will this work? I feel like it should, but I don't want to mess up my controller either by guessing. This would allow me to run 2 cables (I'm using 5 conductor thermostat cable) across the driveway instead of 6 if it'll work.

Edited November 9, 2020 by DocBrown86

[TheDucks]

CMB24, shares the PLUS for the 3 negatives (R,G,B) in the group, so 1 Plus for all 3 lamps, and 3 returns to their respective ports (un-grouped RGB)

[DocBrown86]

5 minutes ago, TheDucks said:

CMB24, shares the PLUS for the 3 negatives (R,G,B) in the group, so 1 Plus for all 3 lamps, and 3 returns to their respective ports (un-grouped RGB)

This is true, but I am using the CMD-16D (link below) which has 16 channels with a pos and neg terminal for each channel.

http://store.lightorama.com/cmdedcca2.html

[k6ccc]

I have several CMD-16D controllers in service in my landscape lighting show - so quite familiar with them.

I'm not really sure I understand what you are trying to accomplish.  Can you draw a simple schematic of what you are wanting, and post it.  Should be doable.  Dumb lights are pretty easy.

 

[DocBrown86]

8 minutes ago, k6ccc said:

I have several CMD-16D controllers in service in my landscape lighting show - so quite familiar with them.

I'm not really sure I understand what you are trying to accomplish.  Can you draw a simple schematic of what you are wanting, and post it.  Should be doable.  Dumb lights are pretty easy.

 

Imagine the 3 red wires and the 1 orange wire being in a cable. Then at the top flood in the photo they would split off to the remaining floods.

So in the cable there is a white, red, blue, green and yellow wire. Let's say the white wire would go to all of the negative terminals, and the red would go to positive on flood 1, green to positive on flood 2, and blue to positive on flood 3, with yellow not being used.

[k6ccc]

OK, you are close.  However the Positive is the common, not the negative.  Do exactly what you want, but it is the positive that would go to all three floodlights, with individual negatives for each flood.  And there is no need to jumper them at the controller end.  Note however that the common positive will be carrying the current from all three floods, so the wire size needs to be large enough to handle the current.

 

[DocBrown86]

24 minutes ago, k6ccc said:

OK, you are close.  However the Positive is the common, not the negative.  Do exactly what you want, but it is the positive that would go to all three floodlights, with individual negatives for each flood.  And there is no need to jumper them at the controller end.  Note however that the common positive will be carrying the current from all three floods, so the wire size needs to be large enough to handle the current.

 

Awesome. Thank you!!

[k6ccc]

BTW, using you wire color example you mentioned with you, I parallel the White and Yellow together, for the common - since that will be carrying the current for all three floods.  No point in having one wire in the cable idle.

 

[DocBrown86]

Thanks Jim, that's a great tip! I don't know why but stuff like that always slips past me until someone else mentions it...