OPII Output question

Can I use two (+) wires for outputs and a common wire (-) for ground for the two outputs?
 
Manual states:
 
GENERAL PURPOSE SWITCHING APPLICATIONS

This output will supply 12 VDC to the output terminal when its corresponding unit is ON. Output 1 is designated Unit 385
through Output 8 which is Unit 392. This can be used to drive relays for many different applications, including switching
sprinkler valves and low-voltage lighting.
 
I am looking to close two switches with three wires going to the panel.
 
Would it be better to use two 12VDC small relays on one/two board(s)s with a common ground?
 
IE: something like this:
 

 
 
IE:
 
OPII ==> Output #4 ==> Relay  #1 12VDC input
OPII ==> Ground #4 from panel ==> ground relay #1 input (can I use any ground from OPII panel?)
OPII ==> Output #5 ==> Relay  #2 12VDC input
OPII ==> Ground #4 from panel ==> ground relay #2 input
 
This is relating to a checks and balances connection to the RFID stuff.

Yeah, the Omni doesn't use isolated outputs, so you can use any ground.
 
The only thing I would consider would be if you are running the Omni output wires long distance, or somewhere they could be subject to lightning or other high voltage exposure.  Putting the relay module you show near the Omni panel, then running the relay switched outputs gives you protection of the local Omni wiring.

Thanks Cobra.
 
Earlier I mentioned I was using three wires.  I am really only using two wires and was going to tap in to a ground from some other OPII connected stuff (PIR).  The two wires are already in the can next to the output terminals and the other side is right next to where I want the relay's to be.
 
So the relays would be powered by the two separate (+) outputs and one PIR (-) connected to the OPII ground wire.
 
If the relays are in the panel wouldn't I need two separate wires (4 wires) for each relay switch output to two areas?
 
The HAI can is over flowing today and really do not have room inside anymore for much. 
 
These two wires are already where I want them to be.  It is indoors and not near HV.
 
The area is about 75-100 feet or so away from the panel.  I do also have a spare cat5e in the vicinity that I used to use to extend an RS-232 connection.  The cat5e is about 20 feet away from where I want the relays. (so its too far and I do not want to run another cable).

Leviton makes a relay board, actually two of them, a 4 relay and an 8 relay.  They have protection diodes built-in to protect the Omni outputs from relay coil surge.  I would't ever run the Omni outputs outside of the panel, they are too susceptible to damage.  Your relay would work fine, but you'll need two. I just put the relays in, and then your set.  I'm thinking about getting a WaterCop, then using a relay to activate it.   

Thanks Ano,
 
I would't ever run the Omni outputs outside of the panel, they are too susceptible to damage.
 
How would the Omni Outputs get damaged? 
 
I am running two horns today (outside and inside) with the horn outputs.  Both are 50 feet plus runs.
 
Are you stating that the optional Omni relay board outputs are better than using the outputs on the OP2 panel?
 
I do not have room to install a relay board today. 
 
I found a couple of tiny 12VDC relays which only need some 5 mV to trip. 
 

 
I was going to utilize the 12VDC from two outputs to drive the relays at the end of the runs.

pete_c said:

Thanks Ano,
 
I would't ever run the Omni outputs outside of the panel, they are too susceptible to damage.
 
How would the Omni Outputs get damaged? 
 
I am running two horns today (outside and inside) with the horn outputs.  Both are 50 feet plus runs.
 
Are you stating that the optional Omni relay board outputs are better than using the outputs on the OP2 panel?
 
I do not have room to install a relay board today. 
 
I found a couple of tiny 12VDC relays which only need some 5 mV to trip. 
 

relay.jpg
 
I was going to utilize the 12VDC from two outputs to drive the relays at the end of the runs.

Click to expand...

The outputs on the Omni don't really have lots of circuit protections like the zone inputs do. How might they get damaged?  Mostly static electricity, indirectly from surges like lightning, and from relay "flyback."  When you power a relay directly, this is a surge that occurs when the relay is turned off.  Since you are using a relay board which a trigger circuit, you don't have to worry, but if you powered the relay directly from an output, you would.  (Google "relay snubber diode")
 
I think the alarm horn outputs are fine.  I wouldn't worry about those. I only worry about the outputs because I have read from people that they have had them go bad.

Yes; the relays are in the house maybe some 50 feet away from the panel.  The two outputs to the two relays are closing a switch with no load on it.
 
Looked inside my panel and I could maybe install the smaller OmniPro relay board or remove one expansion board and replace it with a combo board maybe.
 
This is the beginning of another project.  The third part would be to utilize another output for the water switch via a relay board (like the water cop). 

pete_c said:

Yes; the relays are in the house maybe some 50 feet away from the panel.  The two outputs to the two relays are closing a switch with no load on it.
 
Looked inside my panel and I could maybe install the smaller OmniPro relay board or remove one expansion board and replace it with a combo board maybe.
 
This is the beginning of another project.  The third part would be to utilize another output for the water switch via a relay board (like the water cop). 

Click to expand...

I mounted my relays along the top. You must have lots of stuff in your box.  Getting wires to my panel involves a torturous task of walking hunched down in my attic and with any luck the last wires are just about in now on mine.  Some firewire for an attic sounder, several heat sensors in the attic and garage, wires to the future WaterCop, a cat5 for four sensors that I ran to various sensors for my garage door, and audio wires out to what eventually will provide voice through my house speakers.  Getting wires around the attic has not been fun, and one time I actually drilled into a ceiling sprinkler pipe.  Not fun or cheap to fix, especially since I did it on a Sunday. :angry2:
 
My box is getting pretty packed as well, and it was like 92 degrees yesterday, which means my attic projects are probably coming to the end for the year.  I do need to add a UPB controlled pool table light in my livingroom, but may leave installing that to a real electrician. 

Thanks Ano.
 
I have no room on the top as to the left corner I have the reversing relays and stacked to the right is the second 16 zone expansion board. 
 
In the middle is the micro router.
 
I think I can move the XJack box some and fit it on the right.
 
Found the relay on A.O.
 
Sounds like a PITA to add stuff to your panel.  First door sensor installed here went to the wooden kitchen floor mis measuring (very low on the WAF)
 
Here the attic is large and well lit.  I have to use a ladder for the wire chase on the top.  I built a cat walk/lighting and put some flooring in one section. 

pete_c said:

How would the Omni Outputs get damaged? 


I found a couple of tiny 12VDC relays which only need some 5 mV to trip. 
 

relay.jpg
 
I was going to utilize the 12VDC from two outputs to drive the relays at the end of the runs.

Click to expand...

 
It appears from the image you provided that the relay board has a flyback diode mounted inline with the relay circuit, which, if my view of your relay board is clear, would protect your Omni from the relay coil induced voltage spike.  Can't be 5mV as it's a 12V DC relay. The voltage surge (spike) will be significantly greater than 12V.  The relay boards are nice looking so the manufacturer hopefully put some thought into their design with consideration of both coil surge and contact arcing. While the a spike may not damage any components initially, over time, components will weaken until one pops.
 
Any relay being powered by sensitive electronics, such as the Omni, should have a flyback diode with a drain resistor to limit damaging spikes.
 
I tired to find a complete drawing of the relay board, but no luck for the limited time I searched.

Thank you StarTrekDoors. 
 
So over time using this device I would damage my OP2 board or the relay eh?
 
Yes it is on Amazon (well and Ebay).
 
GEREE DC 12V 1CH 1-Channel Relay Module with Optocoupler H/L Level Triger for Arduino
 
Description is:
 

• the module uses genuine quality relay, normally open interfaces Maximum load: AC 250V/10A, DC 30V/10A
• using SMD optocoupler isolation, driving ability, stable performance; trigger current 5mA (typo above)
• the module Operating voltage 12V
• the module can be high or low by a jumper setting trigger
• fault-tolerant design, even if the control line is broken, the relay will not operate

Been going baby steps with the OP2 (years now). 

That's a nice little unit, when they say Optocoupler, it means that the input (from the Omni) will be isolated from any of the relay surges people have been talking about.  It has an 'electronic' input that will not have surges on it.  The relay board will need it's own 12V power though, to power those input electronics.

Understood.
 
So back to the original post of just connecting said relay to switch on and off remote relay with the panel outputs versus a 4-8 HAI relay board using just three wires from the OPII panel to the relay location.
 
From the verbiage then above I would assume that I need to put a constant 12VDC (from the panel) to the relay and use the outputs for the control terminal on the relay eh?  12VDC is right there from the panel anyways.
 
Is this something that is feasible? 
 
Will I damage the OmniPro 2 outputs utilized? 
 
Should I just quit thinking about this and get a 4 relay HAI board? (am I over thinking this endeavor?)

pete_c said:

Understood.
 
So back to the original post of just connecting said relay to switch on and off remote relay with the panel outputs versus a 4-8 HAI relay board using just three wires from the OPII panel to the relay location.
 
From the verbiage then above I would assume that I need to put a constant 12VDC (from the panel) to the relay and use the outputs for the control terminal on the relay eh?  12VDC is right there from the panel anyways.
 
Is this something that is feasible? 
 
Will I damage the OmniPro 2 outputs utilized? 
 
Should I just quit thinking about this and get a 4 relay HAI board? (am I over thinking this endeavor?)

Click to expand...

You are fine either way, your relays look fine, just be careful when you extend the Omni outputs outside the box because they are susceptible to damage. That isn't to say it will happen, but be careful. 

Thank you Ano.
 
I am changing what I originally installed here that is still using hard wire loops (by passing the panel) that prevented me fat fingering whatever automation lines I had installed on purpose.  (not trusting myself or accidentally creating a circular dependency?). 
 
I am leaving the hardware loops un connected to test.