Electro-Sensor’s FB420 is an integral part of the Electro-Sentry™ Hazard Monitoring System but is also available as a stand alone shaft speed sensor. The FB420 provides a 4-20mA signal directly proportional to the rotational speed of a monitored shaft and has a 4 digit LCD display capable of displaying from 0.000 to 9999. RPM or from 04.00 to 20.00 mA, the display is also used for calibration and trouble-shooting. The FB420 has one relay that can be programmed for failsafe over-speed alarm or failsafe under-speed alarm.

Housed in a rugged, explosionproof NEMA 4X housing, the FB420 is ideal for detecting shaft under-speed or over-speed on a wide variety of industrial machinery. Typical applications include belt conveyors, drag conveyors, bucket elevators, fans, blowers, crushers, and pumps.

• Stand alone or part of the Electro-Sentry™ Hazard Monitoring System
• Compact, self-contained system with sensor and switch
• Simple installation and calibration
• Relay can be set for over-speed or under-speed
• Rugged housing is explosionproof and waterproof - NEMA 4X
• 4-20mA output directly proportional to shaft speed
• Provides real time preventive maintenance feedback
• Prevents product waste, machinery damage and process downtime