VOT overload limiter

The Overload Limiter (OGP) type BOT is an electromechanical safety device for Bulgarian hoists (T, MT series), designed to automatically shut off the hoist mechanism when attempting to lift a load exceeding the hoist's rated capacity.

Operating Principle
The limiter is installed directly on the fixed section of the steel rope under the hoist body.

Mechanics: When installed, the device creates a slight bend in the rope. As the load is lifted, the rope tightens and tends to straighten, exerting pressure on a set of disc springs inside the limiter.

Activation: When the tension force exceeds a preset threshold (usually by 10-25%),
the springs compress sufficiently to actuate a microswitch.

Electrical: A signal from the microswitch interrupts the control circuit for the hoist contactor. However, the "lowering" command remains active to relieve the system.