What is the primary function of a voltage differential relay in an electrical protection system?
1
It detects phase angle differences between the currents and trips the system if the angle exceeds a set limit.
2
It measures the impedance across the circuit and operates when a fault is detected.
3
It compares the current entering and leaving the protected zone to detect faults.
4
It detects the difference in voltage between two or more points and trips the system if the voltage difference exceeds a set threshold.