The SEL-4520 Arc-Flash Test Module is a handheld testing device used to verify the operation of arc-flash detection systems.
It is not the protection relay itself; it is the tool commissioning engineers use to prove that the fiber-optic sensors are working correctly.
The SEL-4520 generates a high-intensity burst of light that mimics the spectral signature of an electrical arc fault.
The Problem it solves: You cannot create a real short circuit just to test your safety gear.
The Solution: You clamp this onto the fiber-optic cable or point sensor. When triggered, it shoots a flash of light into the sensor. The connected relay (e.g., SEL-751) should see this light and trip instantly.
It is designed to test the arc-flash sensors for SEL relays, specifically:
SEL-751 (Feeder Protection)
SEL-710 (Motor Protection)
SEL-849 (Motor Management)
The kit includes adapters to test the two main types of sensors:
Point Sensors: The discrete “eyes” looking into a specific compartment.
Fiber-Loop Sensors: The long, exposed fiber cables that run through the busbar compartment.
- Connection: You attach the SEL-4520 to the fiber sensor.
Mode: You select “Continuous” (flashlight mode for finding breaks in the fiber) or “Flash” (strobe mode for trip testing).
Trigger: You press the button. The unit sends the light pulse.
Verification: You check the relay event report to confirm it saw the “Arc Light” signal.
Manual ⇓
