Application Load Break Interrupter by Powercon Switches are used in the control and switching of power distribution systems with nominal alternating current voltage ratings ranging from 2.4kV to 34.5kV. They can swing from 600 and 1200 amps. Table 1 summarizes the appropriate switching restrictions and criteria. The breaker must be designed for the maximum expected load, so do not use a 500-amp breaker as a replacement for a 400-amp breaker.
Load break switches are designed to open when there is no current flow through them and close when an overload or short circuit occurs. These switches are usually used in three-wire systems where they interrupt the current in one of the wires to prevent damage to other equipment on the line. In two-wire systems, where both conductors carry current during an interruption, these switches function as open circuits that cause both their attached devices to shut off.
The load break switch functions by using magnetic forces to hold its set position. It does this by having one plate of a magnet fixedly attached to one pole of the switch, while the other plate is mounted on a spring-loaded armature that can pivot into and out of contact with the first plate. When there is no current flowing through the switch, the magnetic force keeps the armature in contact with the first plate, which closes the switch.
Capabilities for breaking Approved general-purpose low-voltage fuses must interrupt at least 10,000 amperes in North American usage. Typical commercial and industrial low-voltage distribution system types are rated to safely interrupt 200,000 amperes. The maximum permissible current through an ordinary household circuit is 100 amperes; thus, it is safe to connect a load break switch to any household circuit that carries less than 100 amperes.
In the United States, Canada and most other countries, power companies test loads they intend to be able to break with a magnetic breaker to make sure they can handle the maximum current they will be required to carry when the breaker closes. If the tested load exceeds its intended capacity, then it must be replaced with one that can handle higher currents.
In Europe, power companies test loads they intend to be able to break with a thermal breaker to make sure they can handle the maximum current they will be required to carry when the breaker closes.
In Asia, Africa and Latin America, loads are usually broken by open circuits caused by failure of a component or cable. Thus, they cannot predict how much current a load will draw from a supply but only what minimum level will have to be available from whatever source may be used.
Load-breaking switch A load break switch is a type of disconnect switch that is meant to make or break certain currents. They are used to protect people from being electrocuted by live power lines. Load break switches can be found in homes, schools, hospitals, and other places where electricity is used extensively. They are designed to open the circuit if too much current flows through them.
The two main types of load break switches are magnetic and thermal. Magnetic load break switches use a magnetic mechanism as its force-producing element. These switches are available in single-pole and three-pole configurations. The three-pole version is required when there is a need to interrupt both hot wires to the outlet to prevent current from flowing through persons who may be touching either wire. The single-pole version is sufficient for most applications. Thermal load break switches use a thermally activated element as their force-producing element.
A load break switch is a type of disconnect switch that is meant to make or break certain currents. These switches are used to de-energize or activate a circuit that contains a small amount of magnetic or capacitive current, such as a transformer exciting current or a line charging current. The main purpose of a load breaker is to open the electrical connection between the power source and the load if excessive current flows through the line. This prevents damage to the equipment that both ends are attached to.
Load break switches can be manual or automatic. Automatic load break switches use a sensor on either end of the system to detect a problem before any damage occurs. If an overload or short circuit occurs, the sensor on the other end will activate the load break switch automatically. Manual load break switches require you to physically move something to activate the switch. For example, you could place a rock across the path of a falling object if there was risk of injury from a collision with another object in the room. When the rock is moved, it activates the switch and the circuit is broken.
These switches are required by law for some appliances such as hair dryers and vacuum cleaners. Without one, these products could start a fire when plugged in incorrectly. A load breaker switch is also useful for preventing electric shocks.