Special terminal blocks are designed to allow for disconnection of a circuit, known as opening or closing. Disconnection refers to breaking the circuit and allowing for the current to be stopped momentarily. Disconnecting terminal blocks enable single-wire circuits to be opened or tests performed while the system is still powered on. This special type of block allows users to detect malfunctions and perform off-load maintenance. There are multiple types of disconnecting blocks such as a standard disconnect, which involves a removable insert to open or close the circuit; and also a knife disconnect, which contains a “knife-like” metal piece that can easily open or close the circuit. In general, a disconnect terminal block saves time by allowing an operator to open or close a circuit easily and safely without removing any wires.