# Run multiple zones at once



## mborbi (Aug 21, 2019)

This is what I made to be able to run two zones at once but also keep the ability to run single zones.

My yard has 6 zones and My Rachio Controller is a 12 zone unit. This is how it is set up.

controller output 1 - sprinkler valve 1
controller output 2 - sprinkler valve 1 and 2
controller output 3 - sprinkler valve 2
controller output 4 - sprinkler valve 3
controller output 5 - sprinkler valve 3 and 4
controller output 6 - sprinkler valve 4
controller output 7 - sprinkler valve 5
controller output 8 - sprinkler valve 5 and 6
controller output 9 - sprinkler valve 6

The controller is used to energize the relay coils only. 
The power coming from the relay to the sprinkler valves is provided by a second larger power supply (2.1 amps)





Relay

https://www.amazon.com/gp/product/B07QXW1G25/ref=pe_2640190_232586610_pd_te_s_rtpb_ti?_encoding=UTF8&pd_rd_i=B07QXW1G25&pd_rd_r=1EWNNBZX51B62ZYXCSDN&pd_rd_w=sPL2L&pd_rd_wg=Ic5bQ

24vac power supply

https://www.amazon.com/gp/product/B01N3ALUBS/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1


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## hsvtoolfool (Jul 23, 2018)

Have you considered water hammer consequences of running multiple zones? What is the GPM total for each zone that can run together? What is the mainline pipe size?

For example, suppose all the heads on each zone output 6 GPM. If two zones run simultaneously, a total of 12 GPM flows through the mainline pipe. If the main pipe is 1" PVC, then the water velocity is about 4.9 feet/second. If the main pipe is 3/4" PVC, then the water velocity is over 8 feet/second.

For mainlines the velocity should be kept under 5 feet/second.. So you might want to verify your mainline pipe size and the GPM of the "doubled" zones.


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## mborbi (Aug 21, 2019)

hsvtoolfool thanks for pointing this out and saving me from future problems.

I was more concerned about having enough water pressure and flow to run multiple zones and didn't even consider causing a water hammer issue. The mainline pipe is mostly 1" high pressure poly line with 1" schedule 40 pipes at the valve manifolds and pressure regulator.

Four of the zones are 6 GPM each and two zones are 12 GPM each.

The system has been changed to only allow the 6 GPM zones to be paired together if needed.

controller output 1 - sprinkler valve 1 (6 GPM)
controller output 2 - sprinkler valve 1 and 2(12 GPM)
controller output 3 - sprinkler valve 2 (6 GPM)
controller output 4 - sprinkler valve 3 (12 GPM)
controller output 5 - not used
controller output 6 - sprinkler valve 4 (6 GPM)
controller output 7 - sprinkler valve 5 (12 GPM)
controller output 8 - sprinkler valve 4 and 6 (12 GPM)
controller output 9 - sprinkler valve 6 (6 GPM)


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## hsvtoolfool (Jul 23, 2018)

You're welcome. I never thought about water hammer until I read Mr. Stryker's web site. Now it seems it's all I think about. I suspect liability damages regarding water hammer is the main reason irrigation controllers don't allow two zones to run together. From their perspective, it's better safe than sorry.

Also, I can't believe my random example of 6 GPM per zone actually matches your system! I need to go buy a lottery ticket.


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