Product Details:

The SEW BW090-P52B braking resistor, part number 08245630, is a special PTC type dynamic braking resistor designed exclusively for SEW MOVIDRIVE MDX60B and MDX61B size 0 drives, used for light-duty four-quadrant regenerative energy control. Its nominal resistance is 90 ohms with a tolerance of ±35%, and the rated continuous power is 100W. Different from conventional alloy wire-wound resistors, this model adopts PTC thermistor structure. Its resistance value will rise automatically when the temperature increases, which has inherent self-limiting thermal protection characteristics, and can suppress excessive current and thermal runaway risks under abnormal braking cycles. The suffix -P stands for built-in temperature monitoring function, which can feed back thermal status signals to the drive control terminal for safety interlock.

This PTC braking resistor is connected to the braking chopper terminals of the matched SEW inverter. The core function is to absorb the regenerative energy generated by the motor during intermittent rapid deceleration and light load lowering, convert electric energy into heat, and prevent the DC bus voltage of the drive from exceeding the threshold and triggering overvoltage fault alarm. The PTC material has an automatic power limiting feature. When the internal temperature rises to the critical point, the resistance increases sharply and automatically reduces the braking power, which greatly reduces the probability of permanent burnout of the resistor core. The drive’s internal monitoring circuit can detect the disconnection of the braking loop and the loss of the thermal feedback signal. If the PTC element fails or the cable is disconnected, the braking loop will fail, heavy loads cannot stop quickly, and the system will report overvoltage alarm.

This braking resistor adopts cable outlet connection mode, compact structure and cabinet-mounted installation design. The working ambient temperature range is 0℃ to 55℃, and the storage temperature range is -20℃ to 70℃. The surface temperature of the resistor will rise obviously during braking operation. Sufficient heat dissipation clearance must be reserved around the installation position. Cables, wire ducts and other electrical components cannot cover the heat dissipation area to avoid heat accumulation affecting the self-limiting performance of the PTC element. It can only be matched with size 0 MDX60B / MDX61B inverters, and cannot be used for high-power heavy-duty lifting and high-cycle braking working conditions.

This SEW BW090-P52B braking resistor is widely used as maintenance replacement spare parts for light-duty material conveyors, small packaging auxiliary machines, labeling equipment, light printing auxiliary mechanisms and other low-power automation equipment requiring intermittent braking. Most spare parts circulating on the global industrial spare parts market are fully tested refurbished units. Before installation, technicians need to check whether the cable sheath is damaged and the resistor body is deformed. After wiring, complete jog test and deceleration test to verify the stability of DC bus voltage and the sensitivity of thermal feedback. Regular inspection of cable tightness and cleaning of dust around the installation position can effectively reduce intermittent faults and extend the service life of the braking resistor and the supporting drive system.