Testing your valves periodically is a good thing, right? Not always. In some cases, testing could actually ruin your solenoid valves, making your preventative maintenance have the exact opposite of its intended effect.
Here’s what you need to know to make sure your hydraulic maintenance is preventing solenoid valve problems, not causing them.
Solenoid operated valves are commonly found in many modern hydraulic systems, often in crucial parts like the pump or the motor. If the valves don’t operate properly, naturally you’re going to have a big problem. Your system may not perform at the necessary capacity or it may fail to work altogether. By testing your solenoid valves regularly, you should be able to get peace of mind about their functionality—as long as your do the testing right!
Some mechanics assume that if a solenoid is just a coil of wire for power to travel through, it doesn’t much matter which end they hook up to the electricity in order to test the valve. Just run the juice and if the valve functions, you’re good, right?
Wrong. In some cases, taking this approach can render a perfectly functioning solenoid valve totally inoperable.
The problem is that DC solenoids do have polarity. And if you are using a couple of stripped wires as your connector rather than a real connector with the capability to guarantee correct connection, you have a 50-50 chance of getting the polarity wrong.
With a wrong polarity, the diode normally intended to help suppress voltage spikes inside the coil becomes forward biased. In other words, you get a short which can ruin the suppressor and, if power is applied for too long, ruin your entire solenoid as well.
In order to prevent a short from either ruining your solenoid completely or destroying the suppressor so that the solenoid functions but is vulnerable to kickbacks, you need to read the current before testing any DC solenoid you are not familiar with. Using a DC source with an adjustable limiter is also wise. This allows you to set a limit on the amount of current that can be drawn through the solenoid, so that even if you hook it up wrong, you will not have enough current to ruin the valve.
If you have ruined a solenoid valve, don’t worry too much. Just call Bernell Hydraulics. With us as your solenoid valve supplier you can always rest assured you will receive quality manufacturer-certified hydraulic valves in a timely fashion.