Product Details:

The SEW BTS20-300-40-24 braking resistor is an external dynamic braking resistor designed for SEW MOVIDRIVE MDX61B, MD60A and MOVITRAC B series variable frequency drives and servo drives. Its rated resistance is 300 ohms and continuous power rating reaches 20kW, which is upgraded from the 10kW BTS series models and provides stronger energy dissipation capacity for heavy-duty four-quadrant working conditions. It converts the regenerative energy fed back by the motor during rapid deceleration, emergency stop, load lowering and reverse operation into heat, effectively suppressing the sharp rise of DC bus voltage of the drive and avoiding overvoltage protection faults triggered during frequent braking cycles. This model does not carry the -P suffix, which means it is the basic version without built-in thermal contact switch, so users need to configure an external thermal protection relay in the circuit for over-temperature monitoring according to the on-site safety requirements.

The internal structure adopts high-quality alloy resistance wire winding and high-temperature inorganic insulation filler. It can maintain stable resistance value under repeated instantaneous high-power impact, and has excellent thermal shock resistance and aging resistance. The metal shell adopts natural convection heat dissipation design, and the overall structure is suitable for cabinet installation. It can be directly connected to the braking chopper terminals of the matched SEW drive to realize regenerative energy release. The drive’s built-in monitoring circuit can detect the open circuit and short circuit faults of the braking loop. If the resistor winding burns out or the cable is damaged, the drive will lose the energy dissipation channel, and the DC bus voltage will surge in the process of deceleration, which will cause the equipment to fail to stop quickly and trigger the system fault alarm.

This braking resistor adopts IP20 protection grade, equipped with heavy-duty power terminals for stable high-current connection. The working ambient temperature range is 0℃ to 55℃, and the storage temperature range is -20℃ to 70℃. The surface temperature of the shell will rise significantly during long-time braking operation. Enough heat dissipation clearance must be reserved around the resistor during installation, and cables, wire ducts and other electrical components cannot cover the heat dissipation area to prevent heat accumulation. Since there is no built-in thermal switch, the external thermal relay setting value must be matched with the resistor power and duty cycle to realize reliable over-temperature protection.

This SEW BTS20-300-40-24 braking resistor is widely used as maintenance replacement spare parts for heavy-duty material conveyors, large packaging production lines, lifting hoisting equipment, printing and converting machines and other automation equipment requiring high-power frequent braking. Most spare parts circulating in the global industrial spare parts market are fully tested refurbished units. Before installation, technicians need to check whether the shell is deformed, burnt or cracked, and use a multimeter to measure the resistance value to confirm that it is within the tolerance range. After wiring, complete the high-speed deceleration and load descending test to verify that the bus voltage remains stable during braking. Regular cleaning of dust and debris on the surface of the radiator and inspection of terminal tightness can reduce the risk of overheating damage and extend the service life of the resistor and the supporting drive system.