REO is manufacturing braking resistors for use with Lifts and Escalators where there is a need to absorb surplus energy when these are descending, loaded with humans. The requirements for such an application are demanding because the duty cycle is 100%, there is usually a space limitation and the IP rating has to be fairly high. In response to this requirement REO has built a range of braking resistors, up to 12 kW power rating, that are encapsualted in aluminium heat-sinks.

The winding and encapsulation techniques perfected by REO provide an efficient heat transfer to the cooling surfaces of the heat-sink. Furthermore, the method of construction provides sealing up IP64. The connection to the DC bus is made through special EMC terminations and it is possible to double the cooling capacity by simply fitting cooling fans, using fixing slots, provided within the heat sink profile.

REO braking resistors are used with inverters driving motors with a dynamic load that requires to be stopped quickly, such as lifts, cranes, or high-speed mechanisms. The data sheet shows a selection of the available versions.
Braking resistors are connected into the DC link of an inverter and are switched in automatically, by a chopper, when the DC voltage rises to a preset level.

REO manufacture many different types of braking resistors that are either free standing or can be panel mounted (flat, book or foot print styles depending on available space). There are also compact, fan cooled units in the standard range. A chopper switching card is available as an option.