How to deal with the fault of solenoid valve quickly

Rated voltage of solenoid valve coil is DC12V, DC24V, AC24V (50/60Hz), AC110V (50/60Hz), AC220V (50/60Hz), AC380V (50/60Hz).

Generally, AC220V (no need to install switching power supply, low cost, simple line and easy to maintain) or DC24V (commonly used safety voltage, switching power supply/solenoid valve coil are easy to repair and replace) is used in electrical design.

Test solenoid valve is good or bad method

First to the solenoid valve on the controlled medium (with pressure of liquid, gas "air", pressure value for the solenoid valve using the middle value of the pressure range), and then to the solenoid valve coil energized, if the controlled medium has from the through or from the break to the state of change, then the solenoid valve is good, otherwise there is a problem.

What is the common fault of solenoid valve?

1, coil short circuit or break:

Detection method: First use a multimeter to measure its on-off, resistance value tends to zero or infinity, that coil short circuit or break. If the measured resistance value is normal (about tens of ohm), it does not mean that the coil must be good (I once measured a solenoid valve coil resistance value of about 50 ohm, but the solenoid valve cannot operate, everything is normal after replacing the coil), please conduct the following final test: Get a small screwdriver and put it near the metal rod in the solenoid coil. Then energize the solenoid valve. If it feels magnetic, then the solenoid coil is good, otherwise it is bad.

Solution: Replace the solenoid valve coil.

2, plug/socket problem:

Fault phenomenon: If the solenoid valve is the kind of plug/socket, there may be metal spring problems in the socket (the author has encountered), plug wiring problems (such as the power line connected to the ground wire) and other reasons can not send the power to the coil. It's best to get into the habit of unscrewing the retentive screw after the plug is in the socket, and unscrewing the retentive nut after the spool rod on the coil.

If the plug of the solenoid valve coil is equipped with a LED power indicator, then the use of DC power to drive the solenoid valve will be connected to the right line, otherwise the indicator will not be bright. In addition, do not switch power plugs with leds for different voltage levels. This will cause the leds to be burned/the power supply (replace with a lower voltage level plug) to short circuit or the leds to emit very weak light (replace with a higher voltage level plug).

If there is no power indicator light, the solenoid valve coil is not differentiated polarity (unlike the transistor time relay whose coil voltage is DC and the intermediate relay whose coil voltage is DC in parallel with the diode/resistance leakage loop "This intermediate relay to the original small Japan", need to distinguish polarity).

Handling method: Correct the wiring error, repair or replace the plug and socket.

3. Spool problem:

Fault phenomenon 1: In the case of the solenoid valve through the medium pressure is normal, press the solenoid valve red manual button, the solenoid valve does not have any reaction (pressure medium no on-off changes), indicating that the spool must be bad.

Treatment method: Check whether there are problems in the medium, such as whether there is a lot of water in the compressed air (sometimes the role of the oil-water separator is not very big, especially when the pipeline design is poor, the compressed air through the solenoid valve will have a lot of water), whether there are a lot of impurities in the liquid medium. Then remove water or impurities in the solenoid valve and pipeline. If not, please repair (if you have the time, patience and necessary @_@) or replace the spool, or simply replace the whole solenoid valve.

Fault phenomenon 2: After inspection, the coil is the original coil and the coil is energized when the magnetic normal, but the solenoid valve still does not act (then the solenoid valve manual button function may be normal), indicating that the valve core is bad.

Treatment: Please repair or replace the spool, or simply replace the whole solenoid valve.

As for the maintenance of the solenoid valve body, because there are too many kinds, so a variety of maintenance methods I can not say a lot, here will not repeat.

Solenoid valve failure and troubleshooting

First, the solenoid valve does not work after energized

Check whether the power cable is bad → Reconnect the power cable to the connector

Check whether the power supply voltage is within the ± working range -→ normal position range

Whether the coil is unwelded → rewelded

Coil short circuit → Replace coil

Whether the working pressure difference is inappropriate → adjust the pressure difference → or replace the appropriate solenoid valve

The fluid temperature is too high → replace the appropriate solenoid valve

Impurities make the main valve core and moving core of the solenoid valve stuck to clean, if there is seal damage should be replaced and the filter should be installed

The liquid viscosity is too large, the frequency is too high and the life has to → replace the product

Two, the solenoid valve can not be closed

The seal of the main spool or iron moving core has been damaged → Replace the seal

Fluid temperature, viscosity is too high to replace the solenoid valve

There are impurities into the solenoid valve spool or moving core → clean

Spring life has reached or deformation → replacement

Throttle hole balance hole blockage → timely cleaning

The working frequency is too high or the service life has reached → change the product or update the product

Iii. Other circumstances

Internal leakage → Check whether the seal is damaged and the spring is improperly assembled

External leakage → loose connection or broken seal → tighten screws or replace seals

Noise when power on → strong parts on the head loose, tighten. Voltage fluctuation is not allowed within the range, adjust the voltage. Core suction surface impurities or uneven, timely cleaning or replacement.

Field quick judge solenoid valve is good or bad method

First, check whether the solenoid valve solenoid coil fault?

See whether the solenoid valve gains or loses power, generally at the scene to listen to the sound. If you can't hear, the coil must be a problem, as for the solenoid valve itself is not a problem? (explained below)

If the electromagnetic coil problem, first check the wiring, see whether there is a virtual connection, or a short circuit phenomenon, if there is no problem on the line is the solenoid valve coil burned out, can remove the solenoid valve wiring, measured with a multimeter, if open, the solenoid valve coil burned out. The reason is that the coil is damp, causing bad insulation and magnetic leakage, resulting in excessive current in the coil and burned, so to prevent rain into the solenoid valve. In addition, the spring is too strong, the reaction force is too large, the coil turns too few, suction is not enough can also make the coil burned.

Two, if the coil is good, that is the solenoid valve itself.

Generally can be in the manual adjustment with a word from 1 to 0 position, so that the valve open, if it can be opened that is indeed the coil of the problem, change the coil can be, if not open, disconnecting the solenoid valve, see whether the spool is stuck, or there is a particle block, cleaning correctly should use CCL4, but taking into account the site without conditions, you can use gasoline, It is possible that there is no water, after cleaning can be blown dry with the field instrument gas, be sure to remember the order of the components when disassembling, do not pay attention to it, it is easy to make mistakes when installing, remember wrong order even if you clean the solenoid valve, even if the solenoid valve has been through or can not open!