Schmersal US 432Y-M20 – Pneumatically Operated Limit Switch

Overview

The Schmersal US 432Y-M20 (article no. 101176036) is a position (limit) switch from the Schmersal U 432 series with a plunger actuator and a painted light-alloy die-cast enclosure. It has two normally closed contacts with slow action, double-break switching, and three M20 × 1.5 cable entries.

The switch is used to detect end positions of machine elements and cylinders, for example on pneumatically actuated mechanisms, where a robust mechanical switch is preferred to a proximity sensor.

Key Features

• Plunger actuator, U 432 series
• 2 NC contacts, slow action, double break
• Light-alloy die-cast enclosure, painted, IP65
• 3 cable entries M20 × 1.5
• Mechanical life 10 million operations
• cULus, EN IEC 60947-5-1

Technical Specifications

Applications

• End-of-travel detection on pneumatic cylinders and actuated dampers
• Position monitoring on machine tools, conveyors and material handling equipment
• Door and gate position feedback on industrial machinery
• General position sensing in utility and process plant auxiliaries

Schmersal US 432Y-M20 Selection Notes

Schmersal lists the US 432Y-M20 under article number 101176036 as a metal-enclosed position switch with a plunger actuator and two normally-closed contacts. The contacts are slow-action and double-break, use silver as contact material and have a contact opening of 2 × 1.5 mm. The manufacturer rates the switch for 400 V AC operating voltage and 6 A operating current, with a thermal test current of 16 A.

According to the manufacturer, both the switching points and the contact function can be adjusted, which helps when the switch has to be matched to an existing cam or actuator travel. The basic body measures 62 × 80 × 50 mm, and the overall height including the plunger is 91 mm. Wiring is by screw terminals for conductors of 1.5 to 2.5 mm², routed through three M20 × 1.5 entries.

How the Schmersal US 432Y-M20 Works

The Schmersal US 432Y-M20 is a mechanically actuated position switch. A moving machine part, cam or the rod end of a pneumatic cylinder presses the plunger into the housing. As the plunger travels, it moves the contact carrier and opens the two normally closed contacts. When the actuating part moves away, a return spring pushes the plunger back and the contacts close again.

The contacts are slow-action: the contact movement follows the plunger directly, so the switching point is defined by the plunger travel and the actuating speed has to stay within the manufacturer’s range (minimum 60 mm/min, maximum 1 m/s). Double-break contacts interrupt the circuit at two points, which improves switching of inductive loads such as contactor and solenoid coils. Because the contacts are normally closed, a broken wire or a lost supply has the same effect as an actuated switch, which is why NC contacts are preferred for end-of-travel and stop signals.

Installation and Maintenance Notes

• Mount the switch so that the actuating part approaches along the plunger axis; side loads on a plunger actuator increase wear.
• Do not use the plunger as a mechanical end stop. Leave over-travel margin so that the machine part is stopped by its own stop, not by the switch.
• Use cable glands rated for M20 × 1.5 and seal unused entries with suitable plugs to keep the IP65 rating.
• Tighten the screw terminals to the correct torque and use conductors within the 1.5 to 2.5 mm² range.
• During routine checks, confirm that the switch changes state at the correct position, and inspect the plunger for dirt, corrosion and damage.

Ordering the Schmersal US 432Y-M20

In the Schmersal type code, the M20 suffix refers to the metric M20 × 1.5 cable entries. Other actuator heads (rollers, roller levers) and contact arrangements are available in the same U 432 family under different type designations and article numbers, so the safest way to order an exact replacement is by the article number 101176036 printed on the switch label.

Typical Applications in Oman & the GCC

Metal-enclosed limit switches are used across the region on pneumatic valve actuators and dampers, conveyor and crusher systems in cement and mining, water treatment equipment and packaging machinery. The die-cast housing and IP65 protection suit dusty industrial environments, while the operating temperature range of -20 to +60 °C should be checked for outdoor installations exposed to direct sun.

Why Seven Star LLC

Seven Star LLC supplies Schmersal position and safety switches across Oman and the GCC. Before quoting, we confirm the article number, actuator type and contact arrangement against the existing switch so that the replacement fits the mounting and wiring.

Request a Quote for Schmersal US 432Y-M20 – Pneumatically Operated Limit Switch

Send the article number 101176036 or type US 432Y-M20, the quantity and any required actuator or contact variant through our Inquiry Form. We will confirm availability and respond with a formal quotation.

Related Products

• Cooper Crouse-Hinds GUP315 Explosionproof Junction Box
• MEDC SM87JB Ex Junction Box
• Papts fan
• Phoenix Contact PSR-SCP-24DC/ESP4/2X1/1X2 Safety Relay (2981020)
• Yokogawa S9129FA Backup Battery Pack
• Cooper Crouse-Hinds EFSC215 EFS Explosionproof Pushbutton Control Station