A Guide to Solenoid Valve Connectors

Solenoid Valve Connectors

A DIN C solenoid valve connector din-c-solenoid-connector.png

Figure 1: A DIN C solenoid valve connector

Solenoid valve connectors connect solenoid valves to various other system components, including the power source, control devices, sensors, and transducers. Their basic design comes in three categories, form A, B, and C, which are governed by DIN EN 175301-803 standards. This article covers the structures of the three forms and overviews the circuit functions that work with solenoid valve connectors. Read our overview article to learn more about solenoid valves.

Solenoid valve connector types

There are three basic solenoid valve connectors: Form A, Form B, and Form C. This section describes the general properties of each type. These connectors are governed by the DIN standards:

  • DIN EN 175301-803 Form A
  • DIN EN 175301-803 Form B
  • DIN EN 175301-803 Form C

These standards were formerly known as DIN 43650 Form A, Form B, or Form C. DIN standards ensure that users across a range of industries can be certain a product conforms to a high level of integrity.

Table 1: Solenoid valve connectors' basic properties

Form A solenoid valve connector Form B solenoid valve connector Form C solenoid valve connector
Size Largest Middle Smallest
Pin spacing 18 mm 10 mm or 11 mm 8 mm or 9.4 mm
Number of pins 2 plus ground or 3 plus ground 2 plus ground 2 plus ground or 3 plus ground
Pin shape U-shape 11 mm - flat blade

10 mm - 2 U-shaped and 1 flat blade

Flat blade
Base shape Square Rectangle Square
Note - Also called micro connector Also called sub-micro connector
Diagrams of solenoid valve connectors, forms A, B, and C.

Figure 2: Diagrams of solenoid valve connectors, forms A, B, and C.

Solenoid valve connectors with circuit functions

Solenoid valve connectors with the correct circuit function play a vital role in protecting solenoid valves from damage caused by electrical surges. There are a variety of circuit functions in solenoid valve connectors that play helpful and vital roles. When considering the circuit function of the connector, pay attention to whether it requires AC, DC, or can use both. A solenoid valve connector may have a single or multiple circuit function from the following list.

Solenoid valve connector with LED

A solenoid valve connector with an LED gives a simple-to-understand indication of the valve's power status. This circuit function can use AC and DC and installs relatively quickly. Ensure the available power to the entire connector is enough to handle the LED's requirements.

A Form A solenoid valve connector with LED.

Figure 3: A Form A solenoid valve connector with LED.

Pole protection and freewheeling diode

A freewheeling diode and pole protection circuit function protects a switching DC power supply from transient voltage spikes. This circuit function eliminates arcing across the switch when the power supply is shut off. This is made possible by the freewheeling diode redirecting the current through the coil, which ensures the correct polarity.

A Form A solenoid valve connector with varistor and LED.

Figure 4: A Form A solenoid valve connector with varistor and LED.


Rectifiers convert AC to DC. DC solenoid valves are valued for their quieter operation, ability to work with batteries, and lack of inrush current. Solenoid valve connectors typically use full-wave rectifiers. This means that 90% of the AC voltage is converted to DC.


A varistor protects a solenoid valve connector, its power supply, and the solenoid valve from power spikes. Because it protects the solenoid valve, which can be costly to replace, this circuit function seems to be almost necessary to include. It can operate with AC and DC.

Selection criteria

Solenoid valve connectors have general properties to select between. However, properties can vary between manufacturers, as noted below:

  • Electrical requirements: The different types of connectors have the following voltage and current characteristics, but these can vary among manufacturers:
    • Form A: Voltage rating up to 250V, and current rating up to 16A
    • Form B: Voltage rating up to 125V, and current rating up to 10A
    • Form C: Voltage rating up to 125V, and current rating up to 6A
  • Environment: Determine how a connector will hold up in the environment it will be working in:
    • Temperature: In general, Forms A, B, and C connectors work in a temperature range from -40 °C (-40 °F) to 125 °C (257 °F). This range varies by manufacturer.
    • Humidity: Standard connectors are designed to work under typical indoor environments. For extremely humid environments, opt for a connector with better sealing and moisture resistance.
    • Ingress protection rating: The ingress protection rating (IP rating) determines how protected the connector is from solid particles (e.g., dust) or water. Common IP ratings for connectors are IP 65, IP 67, and IP 69K. These ratings vary among manufacturers.
  • Current: Whether or not the connector operates with AC, DC, or both currents depends on its circuit function (discussed above). When searching for connectors, determine if it has circuit function and what currents it can be supplied with.
  • Size and dimensions: Consider the size of a connector when determining where to fit it in a system. The dimensions of the different types of connectors are discussed above. Form A is the largest and, Form C is the smallest.
  • Thread types: The different connectors have different thread types for the solenoid valve connector wiring:
    • Form A: PG 9, PG 11, M16, and NPT 1/2 inch
    • Form B: PG 9 and NPT 1/2 inch
    • Form C: PG 7

Read our Solenoid valve accessories overview article for more details on the various accessories for solenoid valves.


What is a solenoid valve connector?

A solenoid valve connector connects a solenoid valve to a power supply or other system components, such as sensors.

What are the types of solenoid valve connectors?

There are three standard designs: form a, form b, and form c. Solenoid valve connectors also typically come with circuit functions such as LEDs that display the valve's power status.

View our selection of solenoid valve connectors!