I'm doing some DIY upgrading of my mom's old sprinkler system, in particular, replacing the old rotators with MP Rotators, and installing a new smart controller.
Her old system had five zones; two of them had 3 and 4 heads respectively. I know that with MP rotators I can comfortably run 7 heads on a zone, and I'd like to reduce the number of zones from 5 to 4 by combining the 7 heads onto one zone.
Question: Can I simply wire the wires for both valves into one connector on the new controller, so that the connector will open both valves, or is there some type of amperage or impedence problem with wiring two valves into one zone on the controller?
It depends upon the specifications for the controller.
The electrical requirements for irrigation valves are pretty standard (with some minor variation). In general, they need 24 volts and will draw about 1/3 of an amp as they open the valve, and about 1/4 of an amp to hold the valve open.
So the question is whether or not a single station on your controller can handle the current required for two valves.
Realize that controlers will generally have two specifications in the amperage it can supply. Usually there is a maximum output per station, and another total maximum output. The reason for the different values is that most controllers will have an extra station usually labeled as "master valve". This station ALWAYS turns on when ever any of the other stations turn on. It's purpose is to open a master valve and/or activate a pump relay. The maximum station output defines the amount of current any one station (circuit or master) can supply, while the total maximum output is the total output for the controller.
As an example, I looked up the electrical requirements for a Hunter XC controller and a Rainbird DVC valve. The rainbird valve specified 0.3 amps to open the valve, and the controler specified a maximum station output of 0.56 amps and a total maximum of 0.90 amps. Those numbers mean that the controler can easily handle the load of two valves at once (0.3 + 0.3), but that value exceeds (by just a little bit) the maximum that a single station can provide. So the controller has plenty of power to run a master valve and a circuit valve. But you will be exceeding the specification (by at least a little bit) if you attempt to run two valves off the same station.
Thanks for the detailed info. I'm using a SmartLine SL1600. I've downloaded both the user manual and the installation manual and do not see the output for each zone. Any notions where I can find this info?
(I don't have a pump or a master valve in this installation.)
The smartline web site indicates this is the Technical Information regarding the SL1600 Series.
(I currently can not access the link myself from my office machine).
Laff - that's a sales sheet and now I am convinced that anyone who ever buys anything other than an SL1600 is at best an ignorant fool, and at worst a diabolical scientist doing social psychology experiments on unwitting homeowners.
But nothing on valve voltages. i think I'll simply wire them together and try it.