Electrical Terminal Blocks are classified either by the type of device they are supporting or according to their structure. They can also vary with the type of connections that are made, including both screw-in and screw-less, spring clamp connections, and the popular modular connectors such as the push-in plug-and-socket type.
Structured Types
Single Feed Through Terminal Blocks
Single feed-through terminal blocks are the most basic product type, which are commonly used for simple wire-to-wire connections. Single feed-through blocks have just one input contact and one output contact on opposite sides of the terminal block. One distinct wire goes into the block, another wire goes out of it, and they are connected inside the block housing.
Double Level Terminal Blocks
This type of structure has two ascending levels of contacts, and may use a bridge between the levels to connect them and increase circuit flexibility. This style of terminal block simplifies the wiring and saves on installation space.
Three Level Terminal Blocks
This type of terminal block is basically the same as a dual level type, but with an extra level of contacts stacked on top. They can be bridged in the same manner as dual level terminal blocks.
Device Types
Thermocouple blocks connect thermocouples together and supply consistent metal connections so that temperature can be accurately measured.
Sensor/actuator blocks are designed to handle devices with three or four component wires, such as photoelectric or proximity sensors.
I/O blocks provide direct communication between a control unit and a specific device.
Disconnect blocks, or switch blocks, allow for easy disconnection of a circuit by means of a knife switch, without requiring wires to be removed.
Fuse holders are used to connect together several fuses that are associated with numerous different devices. If a short circuit should occur, the fuse holder ensures that only the wiring sections directly connected to it are affected.
Ground circuit terminals are the blocks used to ground electrical systems or components. They can generally be interchanged with the standard type of Terminal Block Manufacturers’s terminal block and inserted into any block as required.
Power distribution blocks are simply the blocks used to terminate power cables.