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What is a Terminal Block?

Today’s control wiring systems are growing increasingly complex as equipment is confined to smaller and smaller spaces , and industry simultaneously demands more responsiveness and higher levels of automation. For example, these days a packaging system may have a number of points on the conveyor line monitored by sensors. Imagine the hassle involved with running wire from each device to the next, thus creating a spiderweb of wiring. Instead, put a terminal block assembly inside a centralized control panel. You have now centralized and reduced the wiring so that a maintenance crew can quickly assess the status of the system and verify its performance.

Figure 4. Terminal Block Assembly

Within the control panel, these handy modular components can be snapped securely into place on a mounting rail. The designer can also mix and match a variety of application-specific terminal blocks with distinctive shapes, colors and termination markings. When you open the control box door, a quick scan of the wiring is all that’s needed to verify the layout and eliminate guesswork for maintenance and troubleshooting.

When changes in the circuit need to be made, terminal blocks can be easily added or pulled off the rail without disrupting other wire terminations .

Along with reducing the complexity of control wiring, the plastic bodies of terminal blocks also prevent shorts and therefore provide greater safety to installers and maintenance crews.

National Metals received shipment of a new 100-foot long metal polishing system for handling cylindrical stock. The equipment manufacturer’s field installation crew arrived with the equipment and was ready to start setup.

Figure 5. Control Box Capacity

“One of the first things I need to know,” said the head of the crew to National’s production manager, “is whether the existing control box can handle wiring for the new machine.” The crew’s electrician wanted to know if the box had room to handle the equipment’s power needs and other control devices, or if an additional box needed to be installed. “Great,” he thought as he saw there was sufficient room on the terminal block rail.