Due to our territory agreement with Siemens, Lesman is the authorized Siemens sales representative in Illinois, Indiana, Wisconsin, Eastern Missouri, Michigan's Upper Peninsula, and the Paducah, KY area. If you are outside that area, you can find your local sales office or get technical assistance by calling 800-365-8766 or 972-522-4500, or sending an email to piabusales.industry@siemens.com.

Siemens SITRANS WM100 Zero Speed Switch

The Siemens SITRANS WM100 is a heavy duty non-contacting zero speed alarm switch that provides cost-effective equipment protection even in the harshest conditions. The SITRANS WM100 has built-in selectable start delays and one Form C relay contact. It is resistant to dust, dirt, build-up and moisture.

The WM100 monitors the absence of motion on moving or rotating equipment. The device alarms to minimize spillage, prevent extensive damage or fire caused by belt slippage at the head pulley, and warn against conveyor malfunction.

Typical applications include: tail pulleys, driven pulleys, motor shaft sensing, screw conveyor flights, and bucket elevators.

Key Specifications

  • Replaces the retired Milltronics ZSS zero speed switch
  • Up to 4" gap between SITRANS WM100 and targets
  • Non-contacting design eliminates need for lubricating, cleaning, and part replacement
  • Visual indication of target triggered pulse
  • Rugged, low maintenance, suitable for tough environments
  • One SPDT Form C relay contact

Specifications, Manuals, and Supporting Literature

Click the file icon to view the file online, or right-click on the file icon and select "Save Target As..." to download the file to your computer for later viewing.
Tip: If you want to print a large file, download it to your PC first.

Model Selection Guide

Use this table to find the right model for your application.  Don't see the option you need? Call a Lesman sales specialist at 800-953-7626

Description Catalog Number
SITRANS WM100 Heavy-Duty Zero-Speed Alarm Switch 7MH7158-
Model 115 VAC Power
230 VAC Power
ID Tag Stainless Steel 0.5" x 1.75" (16 char.) -Z-Y17
Manual Printed English User Manual 7ML1998-5WM01
Spare Parts Locknut
Mounting Flange
Motion Cable Gland Adaptor Kit


Printed instruction manual should be ordered separately.


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