
Disconnects

Disconnects or safety switches are designed to remove power from a system in a fast, safe and reliable manner. They are utilized in many commercial and industrial settings to provide a safe disconnect of equipment for maintenance, repairs and testing. They are also critical in an emergency situation where equipment must be stopped immediately.
International Electrotechnical Commission (IEC) standards state that disconnect switches must include an indication of its on/off function. When the switch is in the “off” position, it must disconnect all connected conductors. It should also integrate with a padlock that enables operators to lock the power off. Disconnect switches must max out at 600 volts AC power (VAC) and 1000 volts DC power (VDC).
Circuit breakers vs Disconnect switches It is crucial to understand the difference between circuit breakers and disconnect switches. Circuit breakers are designed to remove the current from a circuit when it exceeds a set limit to prevent damage to connected devices. It does this automatically and immediately. A disconnect switch controls the flow of current to a circuit. It manually starts and stops power from an electrical supply by opening or closing an air insulation gap between two conduction points. A disconnect switch usually turns power on and off to a particular device or control panel, whereas a circuit breaker can protect a circuit that contains many switches or devices. Disconnect switches can perform a high number of on and off operations while circuit breakers are not rated for nearly the same amount. In conclusion, a disconnect switch is designed to switch power on and off and a circuit breaker stops the current in an overload condition.
Products
Disconnects are intended to remove and restore power from any electrical equipment that is downstream of that disconnect. In most cases, this is a manual operation and is actuated only when power needs to be removed or restored to a particular circuit. Disconnects do not typically provide any type of state monitoring ability nor do they offer any type of circuit protection, they are simply used to remove and restore power.
It is common to see electrical disconnects used in situations where larger amounts of voltage are present. External disconnects function by allowing the operation of switching power to be performed outside of an electrical enclosure. It is also common to see disconnects require power to be shut off before the enclosure can be opened. This type of disconnect is found on circuits with high voltage potentials and allows for much safer operation when the electrical equipment inside the enclosure needs to be accessed.
Circuit protection devices, such as circuit breakers and fuses, function differently from disconnects in that they have the ability to disconnect power to any devices downstream from their location by monitoring current and power surge events. They are not designed to operate as a switch. When using fuses, if an overcurrent event or surge occurs, they will need to be replaced as they are only intended to be used once. Circuit breakers can be reset, but are not intended to switch power on and off as their main function. In many cases it is necessary to have both an electrical disconnect and a circuit protection device to ensure that any hardware on the circuit does not become damaged because of overcurrent or power surges.