Low-voltage circuit breakers have several wiring methods: front-panel, rear-panel, plug-in, and drawer-type. Unless otherwise specified by the user, front-panel wiring is the most common.
(1) Rear-panel wiring: The biggest advantage of rear-panel wiring is that it eliminates the need for rewiring when replacing or repairing the circuit breaker; only the upstream power supply needs to be disconnected. Due to its unique structure, the product is shipped with a dedicated mounting plate, mounting screws, and wiring screws as per design requirements. It is crucial to note that the reliability of the contacts in a high-capacity circuit breaker directly affects its normal operation; therefore, installation must be carefully performed according to the manufacturer's specifications.
(2) Plug-in wiring: A circuit breaker mounting base is installed on the mounting plate of the complete unit. The mounting base has six plugs, and the circuit breaker's connection plate has six sockets. The mounting base has a connection plate on its surface or bolts on its rear. The mounting base is pre-connected to the power and load lines. During use, the circuit breaker is directly plugged into the mounting base. If the circuit breaker fails, simply remove the faulty one and replace it with a working one. Its replacement time is shorter and more convenient than front-panel or rear-panel wiring.
(3) Drawer-type wiring: The circuit breaker's drawer is accessed by rotating a rocker arm clockwise or counterclockwise. Both the main and secondary circuits use an insert-type structure, eliminating the isolator required for fixed-type wiring, achieving dual-purpose functionality, improving economic efficiency, and greatly facilitating operation and maintenance, while increasing safety and reliability. In particular, the main circuit contact base of the drawer base is compatible with the NT-type fuse contact base, allowing direct fuse power supply in emergency situations.
Since the shunt trip unit, undervoltage trip unit, electric operating mechanism, and interlocking electromagnet have different voltage levels and AC/DC power supplies, users should specify this when ordering. Users cannot use a single accessory; if electrical interlocking of two circuit breakers is required (when one is closed, the other must be open), auxiliary contacts and shunt trip units or electric operating mechanisms can be selected. When wiring front-panel and rear-panel, screws must be tightened to prevent damage to the circuit breaker.
