Electro Magnetic Shoe Brake Details :

Electro magnetic Brakes are used when a load must be stopped rapidly to prevent the load from rotating due to the motor automatic control whether it is a question of stopping at a predetermined time or at selected points of travel or to prevent over travelling.
For fool-proof and safe operation of machinery, modern methods are necessary, which should not tax the operator very greatly. Any machine which requires its motion to be arrested, whether it is a lifting Crane, Hoist, Winch or Mining Haulage today employs a Electro Magnetic Brake, enabling the operator not only to arrest the motion but also to hold the load at any desired point without danger of falling, merely by release of the starting handle. One cannot possibly misoperate the Brake. Nothing safer than the Electro Magnetic Brake is available today. 

Electro magnetic Brake for a given application it is necessary to take into consideration the H.P. Rating and speed in R.P.M. to obtain the required retarding torque. The basic formula against which calculations are made is :
Torque in Kg.M. = (71620 x H.P.) / (R.P.M. x 100)
OR
= (975 x KW) / RPM

For minimum size of Electro Magnetic Brake and maximum efficiency the Brake should be mounted directly on the motor shaft. The application involving arduous duty with more self sustaining load characteristic such as hoist motions of Electric Crane hoists, skip hoist equipment, overload factor must be taken into consideration. In applications of this nature it is usual to assess the Brake torque required on the basis of 150% full load torque.