The CT-3500 S2 is Vanguard’s second generation, stand-alone, digital, microprocessor-controlled, circuit-breaker timer. It measures the elapsed time from the instant a breaker coil is energized to the instant of opening or closing of a circuit-breaker’s dry contacts. In addition to timing a breaker’s contact response time, the CT-3500 S2 can also time relays or other switching functions that use an initiating trigger voltage (24-300 Volts DC or AC). The timer-triggering voltage starts three independent electronic timers. Each timer is individually stopped by its respective dry-contact closing or opening. The CT-3500 can fully analyze the timing of all circuit breaker operations (Open, Close, Open – Close, and Close – Open). Timing results are displayed in milli-seconds and cycles on the unit’s back-lit LCD screen and can be printed on the built-in 2.5-inch wide thermal printer.