wiring a relay (very very OT)

michael · #1 11-01-2002, 11:07 AM

this is OT, but since wiring and relays are common in Jeepsters I thought someone might be able to help me.
I have a sprinkler timer that has 8, individual zones. I'm currently only using 5 (soon to be seven). I was thinking that the low voltage signal from the timer could fire a relay to turn on my pond pump and by fountain. Am I right here? Could I get an outside relay that is connected to the 110V outside outlet and turns on when the timer trips it? I would guess that it would be pretty easy to wire if I found a correct relay. The only tricky part is that I would want to also use the wall switch that currently turns it on as a 3-way so that I can just flip it on if we're out in the back yard.
The reason for all this is that the water needs to circulate regularly to keep it clean (like my pool pump) and now that I'm outside less, having the automatic feature would be helpful.
Ideas?
Thanks
Michael

Jeepster Jim · #2 11-01-2002, 11:16 AM

fill in the pond........j/k

clffhnger · #3 11-01-2002, 01:51 PM

Yes, you can get an Air Conditioning relay that has low voltage contacts and will operate your 110v pump. Usually 16-24 volts will operate it. Called a contact relay.

clffhnger · #4 11-01-2002, 01:53 PM

Being almost Christmas, stores already have the stuff in stock. You can get an inline 110v timer outdoor rated, and they are cheap.

michael · #5 11-01-2002, 02:35 PM

won't work because I need to wire it with a three-way switch, like my hall lights so that I can kick on the pump regardless of the timer position at the time.
Michael

thomjpster · #6 11-01-2002, 02:58 PM

I just got done doing my sprinklers.

The sprinkler timers and valves are typically 24v AC.

NOW.... I'm no expert [img]images/graemlins/crazy.gif[/img] but isn't there a difference between AC and DC energized relays?

Just a thought.

jerryrig · #7 11-01-2002, 03:38 PM

Michael, yes it is very easy to wire thru a 3 way switch. It's going to be a little hard to explain but I will try. In order to do this you will need to run a 110v line to the location of your 3 way. Then you will need 2 wires from there to where your 24vac contactor is located. You will also need to run the 110v line to your pump also from the location of the 3 way. So if you are using romex this is what you should have at the location of your 3 way switch...power in= black, white & ground, Power out to pump = black, white & ground, set of travelers to contactor(any 2 hot colors, but if your using romex it will be black and white & ground.) Now at the location of your 3 way take the 2 white wires (power in, power out and tie them together with a wire nut. Then take the black (power in and tie it together with the black going to the contactor and pigtail a wire off to one of the terminals on the 3 way (not the common though). Then take the white wire from the contactor and tie it to the terminal on the 3 way(not the common). Now except for all the grounds you should have only the black wire that goes to the pump, it ties to the common on the 3 way. Grounds all tie together and bury. That's it, hope it makes sense. If not let me know.

Jerry
1970 Halfcab

GRQster · #8 11-01-2002, 04:37 PM

Micheal,
I've been landscaping and installing irrigation systems for 20+ years now. I don't have my suppliers books in front of me right now but there is a switch that the 24v signal from the controller that would activate your pump.
Many irrigation systems run via a pump rather than city water. When the controller comes on at it's preset time, a pump switch is triggered, thus powering the pump. In this case you would not be using the pump circuit, just one of the zones on the controller.
If your controller has the ability to run the lawn and shrub programs and then has a free program, then you could use it for this.
As far as by-passing the switch so that you can use the wall switch also, it wouldn't work unless you had a separate line that ran from your wall switch to the pump. Then you would have to be very careful not to let them both come on at the same time. That sounds kind of risky.
Let me know what kind of controller you are using and if it has ABC&D programs and numerous start times.
But, my main question to you would be, why don't you leave the pump running continously? All of my pond pumps run 24/7.

michael · #9 11-01-2002, 07:51 PM

I knwo they don't draw much, but it seems wasteful to run a birdbath fountain all the time (unless that's how they are supposed to be and I'm just ignorant). If they SHOULD be on 24/7 then this topic is closed and I'll just plug them in to house current.
As far as the three-way, I'm going to go with a double pole switch. In one position, the socket is on and connected to house current, in the other position, it get's it's black "hot" lead directly from the relay. that way, even if the relay trips, it will go to the swtich, and if it's in the other position the current stops there because there's no complete circuit.
So the only question I have is, is there a relay that will work like a light switch for 110V that is actuated by a 24V signal from the timer. I think this is the only piece that I don't have in the garage. I'm using 12/2 outdoor romex to the outside outlet.
For Richard's benefit, the timer is a Rain Bird ISA 408.
Michael
(see? you guys know alot more than just Jeepsters)

dave · #10 11-01-2002, 10:04 PM

I'm usually way out in left field when it comes to electrical / electronic stuff, but there are Solid State Relays, (SSR's). SSR's are designed to operate on an AC voltages of 110/120 or operate on a 12 volt DC voltage. I've wired several SSR's to turn on/off with 110/120 volt light switches and supply 12 volt DC (low voltage) outdoor lighting. SSR's will have just 4 posts, post one is for AC hot wire, post two is for AC neutral wire, post three is for positive wire of 12 volt DC power source, and post four is will be to the positive wire of a DC pump or light. The DC pump or light will need it's negative wire connected to 12 volt DC power source.
dave