Automating Liftmaster 1/2HP Garage Door Opener

[felixrosbergen]

So I'm starting to get motivated again to do some automatic and was looking at the garage door opener.

During construction i had pre-wired for a garage door sensor at the top of the door, so that should be taken care off pending purchase of a sensor.

I have a conduit nearby the control pushbutton and I've tested that if i create a short/connection between the 2 wires on the back of the pushbutton controller the door will open/close.

So as suggested in these forums I plan to run 2 wires connected to the 2 terminals through a relay at the ELK and control the door in this fashion.

The question is the wire gauge...will doubling up on some cat5e conductors do or do I need something more substantial? The cable used by the electrician to pre-wire for the door seems a bit thicker than cat5, more like cat3 or t-stat wire.

I don't know the voltage or the amperage, but this must be a very common door opener.

Any suggestions? I have cat5e in the house so would prefer to use that.

 

[Sacedog]

The question is the wire gauge...will doubling up on some cat5e conductors do or do I need something more substantial? The cable used by the electrician to pre-wire for the door seems a bit thicker than cat5, more like cat3 or t-stat wire.

Doubling up should be fine. I have 22/2 to my GDO, and most Cat5 is 24 or 26 ga.

The thickness of the wire is usually caused by differences in the jacket or insulation around the 4-pairs.

 

[felixrosbergen]

Any other opinion? Not that i don't trust Sacedog..but it's nice to see consensus..

Looks like I'll need to be getting the Elk Relay expansion..the relay board that connects to the control itself has a flat ribben cable right? How long is this cable? I need to figure out how to fit this into the can.

 

[BraveSirRobbin]

You don't 'have' to get an expansion board, though if you are going to use relays a lot for other items, it's probably a good idea to invest in one now.

For instance, the M1 has a relay on board and you can also just buy a single relay that can trigger off of the analog outputs.

 

[Lagerhead]

Any other opinion?

I am using 24 gauge (a Cat 5 pair) for this as a matter of convenience. The LiftMaster manual recommends "bell wire" which is usually 18 or 20 gauge (right?). My thinking is, the circuit is closed for only one second at a time and anyway it's not really a current application. But this would not be the first time I don't know what I'm doing.

 

[Steve]

I have a 22/2 running to it since all my security wire is 22/. A Cat5 pair by itself (24g) should also be fine. If you have to run something from scratch and you have 22/2 that's what I would use.