Shaft speed switches from Electro-Sensors: complete precision rotation-monitoring systems

The Electro-Sensors DR1000 series

Electro-Sensors makes its measurement products accessible in Canada via Durham Instruments. For instance, the DR1000 series of shaft speed switches consists of complete precision rotation-monitoring systems that are ideal for detecting unwanted slowdown or stoppage of pumps, drive trains, power-driven components, screw conveyors, exhaust fans, and other process equipment. Each unit in this series is perfect for super-slow-speed tasks, with precise setpoint capability over many speeds starting at ½ a revolution per minute (rpm).

Prevent equipment damage, downtime

The DR1000 series is also recommended for crushers, tail pulleys, and elevators, and it monitors shaft speeds, detecting shaft slowdown to within one per cent of the setpoint. A DPDT control relay, rated at 5A at 30 Vdc/l20Vac resistive, operates as the output. Durham Instruments deems these digital speed switches suitable for use in general manufacturing, aerospace, automation, food processing, forestry, the medical field, the military, mining, packaging, power generation, alternative energy, transportation, and research and development.

These shaft speed switches are updated substitutes for the R-series of speed switches. Major features include digital circuitry, easy field calibration and setup, ETL approval as per relevant UL and CSA Group standards, NEMA 4X.7- and 9-rated cast aluminum switch housing, and setpoint range from ½ to 5,000 rpm. Explosion-proof sensors and alternate voltages are among the optional features.

The DPDT relay can be used for equipment shutdown or as an alarm for rotational failure. By preventing equipment damage, product waste, and downtime, the DR1000 series brings efficiency and safety to operations. Each unit works as a system with a remote/external-pulse frequency output sensor and a pulse generator, sold separately. The switch is fail-safe, and any malfunction de-energizes the control circuit.

The most common DR1000 system has a 906 or 907 XP hall-effect sensor and a 255 pulser disc that is shaft-end-mounted and generates an alternating magnetic field picked up by the large-gap sensor. The sensor transmits this speed signal as a digital pulse (frequency) to the switch via three-conductor shielded cable. The unit decodes this frequency signal to determine shaft speed and compare this to the pre-adjusted setpoint.

For more information, contact Durham Instruments.

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