How to wire single-head solenoid directional valve

The wiring of single-head solenoid directional valve needs to be distinguished according to the power supply type (DC or AC) and wiring method (lead type or junction box type). The following are the specific steps and precautions:

1. Wiring according to power supply type

DC power supply (such as DC24V)

Lead type solenoid valve: usually has three wires, namely positive, negative and ground wires.

Positive pole: Connect to the positive pole of the DC power supply (such as DC24V+).

Negative pole: Connect to the negative pole of the DC power supply (such as DC24V-).

Ground wire: Connect to the equipment shell or system ground terminal to ensure safety.

Junction box type solenoid valve: There are usually three terminals in the junction box, which are the power terminal (regardless of positive and negative poles) and the ground terminal.

Connect either end of the power cord (such as DC24V) to the power terminal, and the other end to the other power terminal.

The ground wire is connected to the ground terminal.

AC power supply (such as AC220V)

Lead type solenoid valve: the three wires are live wire, neutral wire and ground wire.

Live wire: The live wire connected to the AC power supply (such as L).

Neutral wire: Connect the neutral wire of the AC power supply (such as N).

Ground wire: Connect to the equipment shell or system ground terminal.

Junction box type solenoid valve: There are usually three terminals in the junction box, which are the power terminal (regardless of the zero and live wires) and the ground terminal.

Connect live and neutral wires to the power terminals at will.

The ground wire is connected to the ground terminal.

2. Wiring according to the wiring method

Lead type solenoid valve

It is suitable for special scenarios such as waterproof type and explosion-proof type, and the leads can be directly connected to the control system.

If it is far away from the control system, new wiring or extension cables need to be added to ensure reliable connection.

Junction box type solenoid valve

Using DIN connector, it is highly popular and suitable for most industrial scenarios.

The terminals in the junction box are clearly arranged, usually marked with power terminals and ground terminals. Just follow the markings to connect.

Advantages: It is not limited by the distance of the control system, and there is no need to break the line in the middle, reducing fault points.

3. Special type solenoid valve wiring

Single coil self-retaining solenoid valve

For DC control systems only, the three wires are A, B, and C, among which B is the common terminal.

When wiring, the common terminal and signal terminal must be connected according to the control logic to ensure that the solenoid valve maintains the correct state.

Double coil self-retaining solenoid valve

To control two electromagnetic coils (such as A coil and B coil), the PLC needs to provide two output control signals.

When wiring, you need to connect the power wires and signal wires of the two coils respectively to ensure the correct direction of action.

4. Precautions for wiring

Voltage matching

Make sure the power supply voltage is consistent with the rated voltage of the solenoid valve to avoid damage caused by overvoltage or undervoltage.

For example: DC24V solenoid valve needs to be connected to DC24V power supply, and AC220V solenoid valve needs to be connected to AC220V power supply.

polarity distinction

The DC solenoid valve needs to distinguish between positive and negative poles. Reverse connection may cause the indicator light to not light up or operate abnormally (but the solenoid valve may still operate).

AC solenoid valves do not need to distinguish between zero and live wires and can be connected at will.

Ground protection

The ground wire must be connected reliably to prevent safety accidents caused by leakage of the solenoid valve.

The grounding terminal can be grounded individually or collectively to ensure that the grounding resistance meets the requirements.

Use of intermediate relay

If the control system output signal does not match the solenoid valve voltage (such as DCS output passive contact), isolation conversion through an intermediate relay is required.

For example: DCS output controls the relay coil, and the relay contact controls the power on and off of the solenoid valve.

5. Wiring example

DC24V single head solenoid reversing valve wiring

Lead type: the positive pole is connected to DC24V+, the negative pole is connected to DC24V-, and the ground wire is connected to the equipment shell.

Junction box type: The power cord is connected to any two power terminals in the junction box, and the ground wire is connected to the ground terminal.

AC220V single head solenoid reversing valve wiring

Lead type: the live wire is connected to L, the neutral wire is connected to N, and the ground wire is connected to the equipment shell.

Junction box type: The live wire and neutral wire are connected to any two power terminals in the junction box, and the ground wire is connected to the ground terminal.