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CU3 Back EMF Monitors

Bulletin 440R CU3 Back EMF Monitors

The Guardmaster® CU3 control unit detects stopped motion and is ideal for use with guard-locking interlock switches. It interfaces with single- or three-phase induction motors by measuring the drive voltage and the back electro-magnetic field (EMF) of the motor. Note that Guardmaster Safety Relays have been marketed by Rockwell Automation under the trade name "Minotaur" in the past.

 

Features

  • Category 1 per EN 954-1
  • Stop category 1
  • Two N.O. safety outputs
  • One N.C. auxiliary output
  • Supports automatic/manual and monitored reset
  • Motor voltage up to 500V max.

Products

  • CU3 Back EMF Monitors

Certifications

  • CE marked for all applicable directives, cULus, c-Tick, and TÜV

Certifications apply when product is marked. See our Product Certification site for Declarations of Conformity, certificates and other certification details.

Learn More

Protect your people, productivity and environment with integrated Safety Solutions from Rockwell Automation. We understand your factory floor challenges and can help you meet your goals, using one of the broadest safety portfolios in the industry.

Rockwell Automation has a global safety team of principle consultants to assist you at any step in a safeguarding project—from training and standards assistance through validation and startup. Learn more about these Safety Services.

Frequently Viewed Publications

TitleNumberLanguage
CU3 Motor Stopped Motion/Slow Speed Detector Installation InstructionsCU3-IN001
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Certifications

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Accessories

We offer a variety of accessories for your Safety Relays, including:

  • 24V DC power supplies
  • Fuses
  • Replacement terminal block kits
  • Ribbon cables
  • Screw and spring clamp terminal blocks
  • Terminators
  • Twist-to-release maintained mushroom head operators

View all Safety Relay accessories