Electric winch with inverter for frequency control of hoist motor - has section switching brake according to command prod. by inverter whilst it delivers three=phase AC to motor

摘要

A r.p.m. regulating system (8, 9) adjusts the rotational speed of the hoisting motor system (2). The rotational speed is controlled corresp. to the output of the r.p.m. regulating system. An on-off operating unit (7) is provided for switching off the braking system (3) which starts depending on a first condition, with which the inverter arrangement (1) begins to produce its output and switches on the braking system (3) de depending on a second condition with which the inverter arrangement (1) ceases to produce its output. An emergency unit (11) detects a third condition, automatically with the second condition remaining inactivated, for the swithcing on of the braking system depending on the detection of the third condition. USE/ADVANTAGE - Prevents falling of suspended load automatically if order for switching off brake is produced by inverter in spite of condition. With failure of inverter AC is not delivered.