I am having a ton of fogginess today thinking of a way to switch a couple On-Off valves with the hardware I'd like to use. When I say 'On-Off', I mean the valves pictured below, where applying voltage to the Open terminal opens it, and applying voltage to the Close terminal closes it. It will stop at any time (last position is the maintained position; I have other circuit components that will allow for this.)

I would like to use a 3-way (SP3T) selector switch to select which configuration to operate: Valve 1, Valve 2, or BOTH.

I would like to use a single, momentary switch in the configuration of On-(Off)-On, or where the center is the normal state (off, nothing energized) and either side is momentarily energizing the OPEN or CLOSED motion of the Selected valve as mentioned above.

Is this even possible? I can't seem to wrap my brain around it today. I've done similar circuits before, but they had the benefit of hot (L) also being controllable with upstream logic, so in a way it was easier controlled.

UPDATE: Link to datasheet. (Pg6, Figure 1 is the particular wire diagram I'm referencing.)


Available hardware

  • 2
    \$\begingroup\$ no, not with the components that you presented ... more components are required, depending on whether the control voltage is AC or DC \$\endgroup\$
    – jsotola
    Apr 27, 2021 at 0:57
  • \$\begingroup\$ Your switches look good. But you need to draw a complete wiring diagram to convenience yourself that if you switch some wrong combination, they won't explode! :). \$\endgroup\$
    – tlfong01
    Apr 27, 2021 at 1:00
  • \$\begingroup\$ Please edit to include a datasheet link (not an Amazon or Ali-what's-it ad page) for the valves. \$\endgroup\$
    – Transistor
    Apr 27, 2021 at 1:12
  • \$\begingroup\$ On the face of it, the ‘both’ setting would connect the two valve inputs together (all the time, not just when ‘both’ is selected). You could do it with a double-pole 3-position switch though. \$\endgroup\$
    – Frog
    Apr 27, 2021 at 1:15
  • \$\begingroup\$ Answer edited to include datasheet. Thanks. \$\endgroup\$
    – Big Owls
    Apr 27, 2021 at 19:57

1 Answer 1


something like this: A 4 pole 3 position rotary (Valve select SW) with an three position center off momentary switch (mode SW)enter image description here

  • \$\begingroup\$ Thanks David! I wanted to be sure I wasn't crazy to think I couldn't do it with just those components. I had a more costly solution designed, so yours is clever and helpful. Very appreciated. \$\endgroup\$
    – Big Owls
    Apr 27, 2021 at 19:58
  • \$\begingroup\$ Should this be a commonly available configuration on a 4P3T switch? Lot of 4NO/4NC's out there, but not quite this. \$\endgroup\$
    – Big Owls
    Apr 28, 2021 at 14:42
  • \$\begingroup\$ This could also be done with a 2P3T Valve Select first, followed by a 2P2T Open/Close. \$\endgroup\$
    – Theodore
    Apr 28, 2021 at 18:32

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