FBM211 Foxboro FOXBORO Controller. Shanghai Sijian Intelligent Technology Co., Ltd. is engaged in technical development, technical consultation, and technology transfer in the fields of intelligent technology, information technology, and automation technology. The company sells electrical equipment, automation equipment, electronic products, communication products, and electromechanical products. Industrial automation products include: PLC, DCS, sensors, frequency converters, encoders, relays, servo drives, soft starters, and touch screens. Product brands involved: Eurotherm, Schneider, Siemens, ABB, SICK, P+F, E+H, Yokogawa, Yamakawa, Mitsubishi, Emerson, Honeywell, FANUC, GE, Eaton Electrical, CT.
FBM211 Foxboro FOXBORO Controller. All soft starter controllers feature motor overload protection. When the soft starter is operating online, its controller can provide overload protection for the motor, eliminating the need to install additional thermal overload relays. Due to the significant harmonic currents after passing through the thyristor, electronic thermal overload relays should not be installed, as their malfunction could prevent the system from operating normally. Since thyristors are expensive and difficult to replace, fast-acting fuses are used to protect them from short circuits that could burn out the thyristors at the output of the soft starter. Figure 4A refers to frequently used applications where no contactor is installed at the input of the soft starter, while Figure 4B refers to infrequently used applications where the power supply to the soft starter is disconnected after shutdown.
Bypass operation soft starters cannot function without a bypass contactor, which is why it is included in both main wiring schemes. The role of the contactor at the input of the soft starter is the same as in online operation and will not be repeated here. It is important to note the thermal relay, which is installed at the output of the bypass contactor and does not carry the starting current. This is particularly relevant for electronic thermal relays, as the high harmonic currents after passing through the soft starter can cause malfunctions and lead to motor shutdown. Additionally, since the thyristor operates only for short durations, there is no need to install fast-acting fuses, which is why they are omitted from the main wiring scheme.
Its main wiring is largely similar to that of the online type. The advantage is that, due to the short operating time of the thyristor, fast-acting fuses are unnecessary. Motor overload protection is achieved through the soft starter’s controller, which not only surpasses electronic thermal relays in functionality and performance but also avoids malfunctions caused by harmonic currents in the main circuit or external interference.