Hydac EDS 8446-1-0100-000 Compact Pressure Switch, 100 bar

A compact switch with a colour-coded switching display

The Hydac EDS 8446-1-0100-000 (HYDAC part number 920859) is the one-output, 100 bar version of the EDS 8000 series. It is simple to set up with two keys and a four-digit display, and the display backlight changes between red and green to show the state of the switching output during operation. Menu names and symbols follow the German VDMA 24574-1 specification for pressure switches.

With a body of only about 70 g, a G1/4 A stainless steel connection and an M12x1 plug, it replaces mechanical pressure switches on pumps, clamping circuits and machine tools where an easily visible set point is helpful.

Technical specifications

Setting the switch

Switch point (SP) and switch-back point (RP) are entered with the two keys; pressure window function uses FL and FH limits. The datasheet lists switching delay times and N/O or N/C function as further adjustable parameters. The minimum difference between SP and RP is 1 bar on the 100 bar range, so hysteresis cannot be made tighter than that.

Ordering notes

Within EDS 8 4 4 6 the pattern shows the metric G1/4 A version with one output (1 in the middle block). The datasheet that goes with this page is the USA edition, which prints SAE-6 psi codes such as EDS 827-2-… with ranges of 500 to 9000 psi, so use it for series features and wiring while the bar range and thread above come from the catalogue entry. Buy the M12 cable separately, as no mating connector is supplied.

The switch is small enough to fit directly into a manifold test port, yet the display stays readable because the backlight colour is visible from a distance, which helps during commissioning. Check the 250 mA switching current against the load, and use a relay or interposing module for coils that draw more. Fit the M12 connector fully to keep the IP 67 rating.

Compact electronic switches like this one replace mechanical pressure switches where drift, vibration and wear are a problem. Record the switch points and hysteresis you require, because they are set by programming rather than by a mechanical screw, and note them on the commissioning sheet.

Selection considerations for an electronic pressure switch

Choose the measuring range from the normal operating pressure and the highest pressure the switch will see, including pressure peaks from valve switching or pump start-up. Peaks above the measuring range shorten the life of any pressure sensor even when they stay below the overload limit, so on circuits with strong pressure spikes a higher range may be the better choice. A switch point near the middle of the range generally gives a better working margin than one set at the very top or bottom.

Next consider the function of the output. A single PNP output covers most tasks such as pump control, pressure monitoring for clamping, or a low-pressure alarm. The window function with FL and FH limits is useful when the machine should only run while pressure is between two values. Confirm that the fluid is compatible with the stainless steel connection and the FKM material listed in the specification.

Installation and commissioning practice

Install the switch on a clean, deburred port with the correct thread form and tighten it to the torque given in the specification. Where possible, mount it so that the display faces the operator or maintenance technician and can be read without removing guards. Keep it away from strong heat sources so that the electronics and display stay within their temperature ranges, which are narrower than the fluid temperature range. Use a correctly wired M12 cable and route it away from power cables.

At commissioning, check that the displayed pressure matches a reference gauge, then program the switch point, switch-back point and any delay times required by the control logic. Test the output by raising and lowering pressure through the set values and confirm that the controller responds as intended. Note the final settings on the commissioning sheet and on the machine documentation.

Integration in hydraulic and process systems

The switch typically feeds a PLC input or a small relay circuit. In hydraulic power units it can confirm system pressure before a machine cycle starts, signal pressure loss, or control a pump in an accumulator circuit. In lubrication and cooling systems it can provide a simple pressure-healthy signal. Because the switch has only one output, a separate device or a transmitter may be needed when both control and alarm functions are required at different pressures.

Operation in GCC conditions

Hydraulic power units in Oman and the GCC often run in hot workshops or outdoors in strong sun. Shade the switch from direct sunlight, which can raise the housing temperature beyond the ambient and make the display hard to read. Keep the M12 connection fully engaged so that dust and moisture stay out, and check the switch points periodically against a reference gauge as part of routine maintenance.

What to include in your RFQ

Provide the full model code, the HYDAC part number, quantity, and the fluid and pressure range of the application, plus the required output function.

Documents and quotation

The EDS 8000 datasheet is attached. Send the full model code and quantity. Related: our pressure instrumentation range.