Switching a low voltage load

[eonibm]

Is there any reason that a 120V normal light switch (on-off) connected to a transformer, that transformer being connected to one irrigation valve and supplying 24V and .28 amps to that valve would not work to turn that valve on and off? The wire between the transformer is 18 gauge low-voltage. I know this is a low-voltage lighting forum (not irrigation) but the advice here is so good I figured someone might know and it is a low-voltage question.

I'd like to turn on and off my waterfall at will by flicking the switch. That switch would turn the valve on, which would send water through the irrigation system to turn the waterfall on. I could put it on a regular irrigation controller I guess, but they are hard to use manually.

[eonibm]

I guess what I actually should do is have the switch connected to a pump, which would then turn the waterfall on and off.

But, I do have a misting system (just for effect) that is connected to an irrigation valve as above and I would like to flick it on and off instead of having it a part of the irrigation system, so I am still curious if it would work.

[sitelights]

You can use an ordinary 15A on-off switch to control a 120v/24v transformer and/or pump. When controlling current in low voltage applications you must always switch the primary (120v) side not the 12v/24v secondary side of the device.

[eonibm]

I am curious as to why you should not switch the low-voltage side.

I was also thinking of putting some switches between a transformer and different 12v lines from the transformer to different sets of landscape lights, in order to be able to choose which lights to have on. Why is this not possible or desirable. The only other option seems to be to have multiple switches each going to a different transformer connected to those lights.

[sitelights]

Unfortunately the "search" function on this site has been limited to posts after April 20, 2005; this is a temporary malfunction. All of the posts are archived and will be available in their entirety shortly. In the interim your time would be well-spent on reading through the posts in your area of interest. It is a common misconception that only the newest posts are relevant when actually the site is much more encyclopedic when read fully.

If you could search "switching" you would be taken to the relevant posts but these would be limited to the more recent posts.

There are numerous posts on your topic of interest: "low voltage control devices" in the Product Review Forum covers your question fully. If you scan through the Control Systems Forum you may find others of interest.

Meanwhile the repair to the web server hard drive goes forward...slowly.

[eonibm]

Thanks. I actually do always search the posts before I post a question and was wondering if it was me, or the search function that had the problem! I'll manually check the other posts!

[eonibm]

I had checked that post previously and am very familiar with that remote control product

My question, though, is: Why this can this not be achieved by putting the transformer in the house and attaching each low voltage wire coming from the transformer to a simple light switch, which would then control that wire and the landscape lighting connected to it.

Is there something about a 12v system that does not allow these ordinary type of switches as a component in the system?

[sitelights]

Note that the 10:1 voltage change (120v to 12v) increases the amperage by a factor of 10 consequently a standard 120v 15A switch could be overloaded i.e equivalent 12v load limit 1.5A. The increased arcing associated with slightly loose connections in low voltage applications creates hazardous conditions easily avoided by using proper equipment and techniques. Of course, homeowners can do as they please.