WIKA PSD-4 Electronic Pressure Switch with Display

WIKA PSD-4 electronic pressure switch with display and IO-Link option

The WIKA PSD-4 is an electronic pressure switch with a four-digit LED display, two configurable switching outputs, an optional scalable analogue output and optional IO-Link communication. WIKA describes it as a universal solution for industrial automation, including hygienic applications and harsh conditions, with accuracy better than ±0.5 % of span and more than 100 million load cycles. Typical fields named are machine tools, hydraulics and pneumatics, special machine building, and the food and pharmaceutical industry. Seven Star LLC supplies the PSD-4 in Oman and the GCC as an independent supplier in Muscat; this page explains the output variants, connections and ranges so the RFQ can be exact.

How the PSD-4 is organised

When ordering the PSD-4 one of three output variants is chosen. Variant 1 gives two switching outputs. Variant 2 gives one switching output plus an analogue output. Variant 3 gives two switching outputs plus the analogue output. IO-Link is optionally available on all three. Switching outputs are PNP or NPN, each with window or hysteresis function and normally open or normally closed contact. The analogue output is 4 … 20 mA, DC 0 … 10 V or a switchable combination of both, three-wire. The signal types and the assignment of the second switch output are set during commissioning, which keeps the number of variants (and spare stock) low.

The analogue output can be scaled in a ratio of up to 5:1, so one instrument can cover different spans. Operation is by three buttons with menu navigation according to VDMA specification 24574-1; the red 14-segment display is turned electronically by 180° and the case can be rotated by more than 300°. Damping, switching delay and reset delay can each be set from 0 to 65 s.

Technical specifications of the PSD-4

Process connections of the PSD-4

Connections cover G 1/4 A and G 1/2 A per DIN EN ISO 1179-2, G 1/4 B and G 1/2 B per EN 837, 1/4 NPT and 1/2 NPT, R 1/4, PT 1/4, G 1/4 female (Ermeto compatible), G 1/2 B flush, G 1 hygienic and TRI-CLAMP 1 1/2 in and 2 in. The maximum range depends on the connection: 600 bar on most, 1,000 bar on G 1/2 B, NPT and the female G 1/4, and 25 bar on G 1 hygienic. Pressure port diameters are 3.5 mm as standard, with 0.6, 0.3 or 10 mm optional on non-flush connections. Temperature error between 0 and 80 °C is ≤ ±1.5 % of span for pressure-port versions, rising to ≤ ±2.5 % for the increased overpressure limit and G 1/2 B flush and ≤ ±3.5 % for the hygienic connections.

Approvals listed include EU declaration of conformity (EMC), EAC, UL, CRN, and for hygienic connections 3-A and EHEDG, with a range of food-grade seals available. Short-circuit and reverse polarity protection and DC 500 V insulation are built in.

Where the PSD-4 fits and related WIKA instruments

The same family design principle is used in the electronic temperature switch TSD-30 and in the FSD-4 flow switch, so panels can share wiring, display layout and IO-Link handling. For analogue-only duty the S-20 and S-11 transmitters are the better fit. Where a mechanical gauge with contacts is wanted, consider the PGS23.100 switchGAUGE. For pulsating lines place a 910.12 snubber or 910.13 overpressure protector ahead of the PSD-4, and use 910.17 sealing rings where the connection needs one.

Selection and ordering checklist for the PSD-4

• Pressure range, gauge or absolute, and unit.
• Process connection and its maximum pressure; hygienic or flush if media are viscous or hygienic.
• Output variant 1, 2 or 3, and the analogue signal type.
• PNP or NPN switching, window or hysteresis function.
• Whether IO-Link is required.
• Connector pin count (4-pin or 5-pin) and mating cable.
• Seal material and temperature limits.
• Hygienic certificates (3-A, EHEDG) when relevant.

Installation, commissioning and maintenance of the PSD-4

Connect the supply and loads according to the pin table: U+ pin 1, U- pin 3, analogue S+ pin 2 (4-pin) or pin 5 (5-pin), SP1 or IO-Link pin 4. Set the display unit, switch points, hysteresis and delay values through the menu, and save the settings. The zero point can be corrected within ±3 % of span. If IO-Link is in use, condition data and diagnostic functions report whether the pressure or temperature is outside the specification. Tighten the connection to the torque of the mating thread, and check that the mating connector has the same IP rating as the switch, since IP65 and IP67 apply only when plugged in correctly.

Typical applications in Oman and the GCC

In the region the PSD-4 is used on hydraulic power units, compressors, pneumatic lines, lubrication systems, filter differential monitoring by pressure, dosing skids and packaged water treatment. The IO-Link option makes it suitable for newer machines and OEM skids delivered to GCC projects. The 85 °C medium limit and 80 °C ambient limit should be checked for sun-exposed panels.

PSD-4 output variants

Information to send with an RFQ

• PSD-4 with range, pressure type and unit
• Process connection
• Output variant and analogue signal
• PNP/NPN and IO-Link requirement
• Seal material and hygienic certificate needs
• Quantity, delivery site and documents

Documents and quotation

The WIKA data sheet for the PSD-4 is attached on this page, with the range tables, connection list and dimensions.

Send the range, connection, output variant and quantity and Seven Star LLC will confirm availability and a quotation.