0-10v LED dimmer on separate phases

[dpcarls1598]

I am currently retrofitting a large classroom with 2x4 LED troffers from Cree. I have been using dimmers (0-10v) for the other rooms but this room is fed with two separate 277v circuits due to it's original lighting load. The dimmer I am using can handle 60 fixtures (only using 28) but one row is on a separate phase from the others and they only want one dimmer.
I have called Cree and Leviton (dimmer manufacturer) and both have not been able to answer this question...
Can the 0-10v dimmer wiring jump from drivers on one phase to another or will that damage the driver/dimmer? Anyone done this? I can rewire the room but not in the amount of time I will have for the job.
Thanks in advance and yes, it's my FIRST POST!!!!

 

[ActionDave]

No, you can't do this. If I understand what you mean by "wiring jump from drivers on one phase to another" you'll have a phase to phase fault.

 

[GoldDigger]

No, you can't do this. If I understand what you mean by "wiring jump from drivers on one phase to another" you'll have a phase to phase fault.

My understanding of the question is whether you can feed the same 0-10V (or 1-10V) signal to dimmers on two different phases.
It comes down to whether the control signal is ground or neutral referenced or phase line referenced or ideally optically isolated.
The power inputs would remain separate.

 

[n1ist]

Does the driver specify that the 0-10v circuit is class-2 compatible? If so, they are likely isolated and OK. The last 0-10v design I did (for a different vendor) was transformer isolated so it would have worked across phases.
/mike

 

[chris kennedy]

I am currently retrofitting a large classroom with 2x4 LED troffers from Cree. I have been using dimmers (0-10v) for the other rooms but this room is fed with two separate 277v circuits due to it's original lighting load.

With the new LED load can you lose a circuit and have the whole room on one?

 

[Smart $]

...I can rewire the room but not in the amount of time I will have for the job.
Thanks in advance and yes, it's my FIRST POST!!!!

Welcome :thumbsup:

With the new LED load can you lose a circuit and have the whole room on one?

This would be the easiest solution.

May only require switching a couple/few wires to different wire nuts.

 

[rlundsrud]

With the new LED load can you lose a circuit and have the whole room on one?

This would be my solution as well. The typical power consumption ratio in the conversion to LED is about 4:1, so you should have about 1/4 the watts being used and should have plenty of capacity on one of the circuits.

 

[Electric-Light]

Most ballasts are sourcing, each providing 1mA.
If you've got 10 ballasts in parallel, that's 10mA source.
The dimmer pulls it down down by sinking the voltage.
It wouldn't be damaging, but it might malfunction if one set is turned off.

Larger concern:
If you've got 10 additional ballasts hooked up, can they be back fed 10v while they're turned off without sinking the bus? You need to ensure this to avoid malfunctions in the form of ramping up and down or flashing.

Lesser concern:
Is the dimmer actively managed? When 10 ballasts are switched on, there's 10mA. When 20 are turned on, there's 20 mA. An active dimmer would hold the bus at the same voltage and the level stays the same. Otherwise, one set getting turned off will affect the level.

The typical power consumption ratio in the conversion to LED is about 4:1

:lol: :lol: :lol: :lol:
Compared to halogen.