Typically, a phase loss is caused by a blown fuse, thermal overload, broken wire, worn contact or mechanical failure. Phase loss protection refers to safeguarding the power system when a phase is lost in a three-phase AC supply. It not only drives large motors but is also widely used. When one phase of a three-phase system is lost, a phase loss occurs. This is also called 'single phasing'. When a phase loss causes a significant current increase in the remaining phases of the motor circuit, there is a major increase in rotor current that can cause motor damage. This causes motors to draw unbalanced currents and quickly overheat.
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