# Can I control a solenoid valve below its nominal voltage?

I need to control the following 2 ways direct solenoid valve ("Series 252 D01") :

https://www.emerson.com/documents/automation/catalog-series-252-dental-manifolds-asco-en-6779448.pdf

It is rated at 24 VDC. If I apply this voltage, the valves opens (it is normally closed) and it consumes approx. 170 mA (meaning its power is 4 W).

But the valve also opens up at approx. 15 V (it consumes 100 mA -> 1.5 W). Once it is opened, I can go down to 3 V (it consumes 0.18 mA -> 0.5 W), and closes at 2 V.

Because the solenoid heats up at 24 VDC (approx. 50 °C after 15 min), I was wondering if I could control it as follows : I open it at 24 VDC and maintain its opening by reducing the voltage to 3 V. I can achieve this behavior with a PWM and a transistor.

Do you think it is a good or a bad idea ? What could go wrong ? Is it something which is usually done or not at all ?

If not, is it possible to reduce the heat while maintaining the proper functionning of the valve ?

Thanks.

• It is always a bad idea to be below/higher or too near of limits specified by the seller on any equipment. So first try to specify how legit it can be from your needs.
– user201301
Nov 16, 2021 at 13:39
• Yes, "hit and hold" is relatively common with solenoid valves. Some valve datasheets do say not to do it, while others encourage it by specifying a minimum hold current. In any case be generous with margins. Current control is something to look at too. Nov 17, 2021 at 0:36

• Power dissipation will be $$\ \frac {V^2} R \$$ so reducing the voltage to 75% will result in a power reduction to 56%. There's no need to go as low as 3 V unless energy consumption is an issue.