installing Elk P112

[MarkJames]

Hi all,

I have a large reach system - several hundred feet out to some out buildings.  I want to add additional power along the daisy chain for the furthest devices.
 
I have a P112K that I've put on the line right beside an M1XRFEG.  I'm assuming that I would remove red and black (power) from the M1XRFEG that originates at the M1 and replace it with the power supply from the P112K.  Injecting 12V into the system from a second system seems wrong to me but I can find no documentation. 
 
Does anyone know the answer to this?  Should I completely separate them?  Separate the grounds?  Separate the +12?
 
Thanks!

 

[RAL]

You should connect the +12V and NEG terminals on the M1XRFEG to the P112 power supply outputs.  Also connect the Elk data bus NEG  wire to the NEG output of the P112.  Do NOT connect the +12V of the P112 to the Elk data bus +12V wire.   You want to have a common signal ground, but do not tie the +12 outputs together. 
 
There is a wiring diagram on page 13 of the M1 installation manual that shows an example of this.   Look at the dashed box in the lower right corner of the diagram.

 

[MarkJames]

Perfect!
 
That makes total sense.  Thanks for your help.
 
mark