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 braking resistor is connected in the DC link, between the rectifiers and the switching semi-conductors. When the DC voltage rises, to a pre selected limit, a chopper circuit switches in the braking resistor thereby allowing excess energy to be "dumped" in the form of heat, instead of causing damage to the inverter. When the DC level drops to a lower preset minimum limit the braking resistor is switched out of circuit until it is required again.
Application Information:
SBH: The resistive element is a low ppm resistance wire that is wound on a special grade porcelain tube. The terminals have fully welded construction to provide a good mechanical and electrical contact. The assembly is embedded in the aluminum casing. The aluminum casing is made from high quality heat sink grade material, which helps to dissipate the heat from the resistor at the faster rate resulting low change of resistance with respect to temperature, as resistance varies in direct proportion to temperature. The casing is filled with high purity and special silica sand to extract the heat from the resistor body at the slower rate. The conduction of heat thorough the sand brings uniform heat to the aluminum casing for further dissipation. This protects the panels from being heated internally. Terminal contacts are provided with the screw arrangement for easy wiring.
Construction
Features:
"SURE" BRAND WIRE WOUND RESISTOR - SBH BRAKING RESISTORS - Professional Grade |