The following dimensioning parameters must be taken into account when a brake is selected:

Braking torque

On the assumption that the deceleration rate must be approximately equal to the acceleration rate, the braking torque should be calculated as follows:

M_BR = M_Ja Г— О·²

Accordingly, the braking torque of the mechanical brake must be approximately equal to the required maximum motor torque.

Braking energy on emergency trip

The braking energy for occasional emergency trips must be checked to ensure that it does not cause the brake to overheat. Please refer to table in section "Technical specifications" for permissible values. The braking energy produced for traversing gear can be calculated approximately with the following equation:

The total moment of inertia I_tot is the sum of the individual moments of inertia of the plant components to be braked, reduced to the brake (motor) shaft, and the moment of inertia of the linear-motion masses. The equivalent mass inertia I_Eqv of a linear-motion mass m with velocity v, referred to the brake (motor) speed n_Br, is calculated as follows:

The velocity and/or speed to be entered here must equal the maximum values in normal operation. An increase in velocity resulting from wind forces may also need to be taken into account.

Braking energy and energy capability

The brake must be capable of absorbing the heat produced by the occasional emergency braking operation. The maximum permissible energy capability Q is shown in the diagram below as a function of the number of switching operations.

The permissible energy capability Q for a single emergency trip can be found in the table in section "Technical specifications".

Energy capability Q, braking speed n  = 1500 rpm