Test Equipment for Traffic Signal Control Systems
LST 650
Load Switch Tester
The LST-650 NEMA Load Switch Tester (Tester) is an automated tester designed to test Load Switches
used in traffic signal installations conforming with NEMA Specifications.
The Tester performs a quick functional test of the Load Switch under simulated normal conditions. The
following parameters are tested:
● DC input turn-on and turn-off voltage
● DC input maximum turn-on current
● AC output turn-on and turn-off voltage
● AC output leakage current
● AC output turn-on and turn-off time
The Tester connects to a Windows based computer with a USB connection. The LST-650 Test Manager software controls the Tester and allows the users to run manual or automated tests.
NOTE: The LST 650 performs functional testing. It does not test to the limits of the NEMA standard. The AC loads are approximately 240W and 12W depending on line voltage fluctuations.