Why can 4 and 5 be shorted together? The short circuit between 4 and 5 is equivalent to the blue wire connection 5, which is the normal braking mode. The normally open circuit can be connected between 4 and 5. When the motor is powered off, the DC circuit between 4 and 5 is cut off, and the coil is powered off instantly, forming a rapid braking. At the same time, SR or UR of SEW can be connected between 4 and 5, one is a current relay and the other is a voltage relay, which is used to cut off the circuit when the motor is powered off. SR or UR is used a lot because it is installed in the junction box, which saves the trouble of laying cables. Of course, many sellers don't know this thing. The specific selection depends on the different types of motors, such as UR can be used in multi-speed motors to provide special braking voltage, SR is only used in single-speed motors and so on. ...
Why are the brake coils three wires? SEW has a patented dual coil system with TS and BS coils. BS is an acceleration coil, which can open the brake at the limit speed. After each operation 120ms, it will switch to TS+BS holding coil, which has the advantages of large acceleration current, good reliability, small holding current and long service life. The braking response time of the two wires is long and the coil attraction is small. ......
Well, you should understand after saying so much. If you don't understand, ask me.