I really don't like switching 120 VAC via relays and also having to run that high voltage inside a control box (i.e. where the Elk is installed). It just makes working on that box more complicated because you have to then watch touching any of the high voltage terminals.
If you do want to switch high voltage via a relay, I would mount a relay in its own small box near the outlet, and then run the 12 volt control wiring to the Elk. This could get messy when trying to comply with code as you would have to cut off an extension cord, plug the male end into an outlet, run the cut end into a box with the relay, mount the box on a wall, cut the cord to the lighting transformer and run that cut end into the newly mounted box. It's my understanding (though I am FAR from a code expert) that you can't permanently "mount" anything that is plugged into an outlet via a flexible cord. Also, you get into that low voltage and high voltage wiring mounted inside the same box issue. Again, it's my understanding that the wire type should be rated for the highest voltage inside the box.
These reasons are why I just mounted an X-10 (yes I still use that technology) outlet in an outdoor rated enclosure, and then just plugged my outdoor lighting's transformer in that. Pictures are available in
THIS How-To. This method complies with code as it has a rain-tight enclosure and is GFCI protected.
If you want to switch the low voltage side you can indeed use relays as was mentioned above. You would need to use (again mentioned above) the Elk type relays to trip an automotive type relay since the Elk relays can't handle the amperage required.
Since you have an XOVR you can simply use the relays on it to drive automotive relays. You can't use the eight voltage outputs directly as they will only provide 50 milliamps of current (not enough to trip an automotive relay).
You may want to consider a relay of
THIS type with it's corresponding
SOCKET. It's cheap and can handle 30 amps. Note that the coil resistance is 88 ohms so it will only draw 12 volts/88 ohms = 0.14 amps or 140 milliamps off of your 12 volt source. You can easily mount that relay on a wall or board also.
You would then connect the Elk Relay's "C" to the + 12 volt source, the "NO" to the + coil input of the automotive relay, and the - coil input of the automotive relay to the - 12 volt source. Just be aware of your total 12 volt draw on your overall system. If you are switching a large group of relays (with several on at once) and if your XOVR is a large distance away from your M1, you may want to consider using a 12 volt wall wart as the source plugged near the relays. I would also consider placing an in-line fuse if using the Elk's main 12 volt source so you will not bring down the entire system in case of a problem with these relays.
The "NO" and "C" of the automotive relay would then just switch your + leg of the low voltage transformer’s output.
You could create several switched legs by using multiple relays and separately switch your back yard from your front yard if you wish.
Just some more ideas to kick around! Good luck and let us know if additional details are needed. :huh:
