im buying [smc VQZ 212 5YZ1 C6] 3 port solenoid valve with 2 possible position(let say A and B).

This solenoid work with 24VDC and have 3 pin/ wire. There is No 1, No 2 and GND pin.

I will never tried to wiring directly without enough information. How to switch the solenoid valve position (from A to B and from B to A) with 2 wire 24V adapter (24V and GND)? What does (-)(+) mean in wiring diagram? The full manual book is here

wiring digram from manual

  • \$\begingroup\$ Hello Patrioso, the (+)(-) means "connect it one way, and the "A" port is activated." Reverse the connections, and B is activated. Ground is just that - ground. Ground is not used to control the solenoid. \$\endgroup\$
    – rdtsc
    Nov 21 '18 at 2:43
  • \$\begingroup\$ @rdtsc so, always connect gnd to gnd. if i want to position A put +24V adapter to NO. 1 and leave NO 2 without any wire. And for position B put +24V to NO 2 and leave NO 1 without any wire? Based on this diagram, what happen if i connect paralel No 1 and No 2 to 24V at the same time? \$\endgroup\$
    – Patrioso
    Nov 21 '18 at 2:55
  • \$\begingroup\$ No, ground is a safety connection. Ground is connected to Earth ground, and is not used at all to control the solenoid. The solenoid is controlled by the direction current goes through No1. and No2. terminals. Put the 24v in one way, and A will activate. Put 24v in reverse (swap wires to No1 and No2 termnals), and B activates. \$\endgroup\$
    – rdtsc
    Nov 21 '18 at 11:32

-The wiring of the solenoid is the same no matter the valve configuration. (2, 3, 5 port etc).

-All solenoid valve coils are non-polarized. If you put a voltage across No1/No2 in any polarity it will activate the coil. The connector is designed to be flipped 180 degrees if needed for physical placement reasons, so everything in the connector is non-polarized. Hence the bipolar LED and an a varistor for surge protection instead of a diode. So just connect +ve/-ve on No1 or No2, it doesn't matter.

-The GND pin is PE GND not -ve(GND). It's for AC earth connection on an AC solenoid coil and not used for DC.

-As for how the A/P/R ports on the valve side behave when the coil is activated, that's a different story and you'll have to look at the valve diagram to work out what does what.

  • \$\begingroup\$ @rdtsc Sorry that's not correct. The electrical side is only off/on and switching polarity doesn't change port selection. The valve switches position with coil on/off and whether that is A/B or B/A depends on the valve diagram. \$\endgroup\$
    – Alex
    May 11 '20 at 0:32
  • \$\begingroup\$ "The connector is designed to be flipped 180 degrees ..." This is incorrect too. The mini-DIN plug cannot be reversed as the third pin (shown in the bottom diagram) prevents it. What can be done is rotate the shell in 90 degree steps. The actual plug connection is fixed. "... so everything in the connector is non-polarized." Rotating the connector on the valve (if possible) wouldn't change the polarity within the plug. \$\endgroup\$
    – Transistor
    Jun 16 '20 at 6:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.