Jun 232012
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Many sprinkler systems require that the timer supply power to a relay in order to send power to a sprinkler pump. Often the sprinkler system is using secondary water and is not connected to the culinary water running to the house. And many times the secondary water is supplied at very low pressures requiring the addition of a sprinkler pump.
The way this works is:
- The wires from the relay are connected to the master valve circuit on the timer (see photo). One wire to the MV or master valve terminal, and one wire to the common terminal. When the timer activates it sends power to the relay.
- When the relay receives power it closes the contacts and power is then sent to the pump to activate. Most pumps are pre-wired for 230 volts, but the selector on the pump can be changed to use 110 volts. It is very important when wiring a pump to be certain which is being delivered to the pump, 110 or 230 volts. If the wiring is wrong you could end up burning up a pump, and they are not cheap. A common 1.5hp sprinkler pump can run as much as $400-$600. Yes I know you can buy one from the home improvement stores for $199, but my experience is that they only last a few years and then the expense of a new pump and installation costs start all over again.
- At the same time the timer/controller is sending power to the sprinkler pump, it is also sending power to the sprinkler valve and opening the valve. So when the pump pressures up the system the sprinkler zone is open and waiting for the water.
- When the cycle is complete and the timer shuts off the power to the sprinkler valves, it is simultaneously shutting of the power to the relay and the pump. It varies from timer to timer, but most Master/Pump circuits are on by default on the sprinkler timer/controller.
- Below is a typical drawing and description of a Hunter SRC series timer Master/Pump valve wiring. Most sprinkler timers will be similar to this example.
- Route wires from the master valve or pump start relay location into the controller with the valve wires.
- Connect either wire from the pump relay to the MV terminal. Connect remaining wire to the C (common) terminal.
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We have a Hunter Pro-C controlier.
We also had sod installed 7-27-2012.
Does this system have a New lawn setting and if so how do you get to it.
Thank you, Tom and Linda Fish
I don’t know of any timer that has a new lawn setting. My suggestion is to set up timer for new sod watering by doing the following:
1. Put the new sod watering on its own program.
2. Turn all the water days on this program ON.
3. Use all 4 start times on the program. When I do new sod I set the start times at: 8am, 1pm, 6pm, & 1am. This way I’m watering more during the day when the sun is out and turf dries out faster.
4. I usually set the station run time from 8-12 minutes (double this if your new sod is being watered by rotors). You will have to tweak this on your sod depending on the soil type. You want the sod to stay moist for a couple of weeks until the roots start setting.
Let me know how this works.
Interesting. I love the idea of a timer like this. Having a nice irrigation system gives you one less thing you have to worry about. I’ll take that!
Bruce@ Outdoor Sprinkler Systems
We are having a problem with this kind of timer. The fuse keeps blowing. We have replaced valves that were leaking hoping that would solve the problemm but it still occurs. We need help. Not sure what to try next.
Normally a short in the solenoid on a sprinkler valve is what causes the fuse on the timer to blow. It’s going to be a process of elimination to find your short. Here’s what I would do:
1. If you don’t have one buy a circuit tester. I like the digital battery powered ones that you can buy for $29-$49. You’ll probably need some more fuses also.
2. Disconnect all the station wires and common wire from the timer. If you have a pump disconnect the two wires running to the relay from the timer.
3. Manually start station 1 on the timer and use your tester (red probe on the station 1 terminal and black probe on the common terminal) to test the timer’s output. Check the output from the timer to station 1. You should be getting 24-29 volts. We’re first checking to see if there is a problem with the timer.
4. If everything checks out here, manually start and test the rest of the stations you’re using on the timer. If you get 24-29 volts on the rest of the stations you’re using, the timer is OK and we can move on.
5. Connect the valve wire from station 1 to the station 1 terminal. Connect the common wire to the common terminal. Manually start station 1 again. That station should water with no problem. If you have a pump let me know and we might have to change the troubleshooting sequence. If station 1 waters and the fuse doesn’t blow, everything from the timer to the valve is good on this station. Repeat this process for the rest of the sprinkler stations you are using on your timer until you get to the station that blows the fuse. If any station blows the fuse then there is probably a problem with the timer wire running to the valves.
6. If only one station blows the fuse, then you have found the culprit. Replace the fuse and leave this station disconnected until you solve its problem. Normally it’s a solenoid in this situation, but it could also be a short in the timer wire between the timer and the valves.
After doing this bit of troubleshooting, let me know what you find and we can decide on what needs to be done next. KT