Motion-sensing product safeguards rotating machinery
Castell
The interval between a rotating machine being switched off and coming to a complete standstill can be 15–30 minutes — a time that is most dangerous for workers needing to access the unit. The BEMF unit (photo) is a motion-monitoring product designed to protect workers. It ensures that large, motor-driven rotating equipment up to 600-V with a variable rundown time has completely stopped completely (even after it has been switched off) before access is possible. The BEMF unit detects zero electromotive force (EMF) from the motor, and releases a “trapped key” corresponding to a lock on the machine’s guard hatch. Access cannot be granted without the use of this key, and power cannot be restored to the motor until the key is returned, says the company. — Castell, Chicago, Ill.