The Vanguard DIGITMR S2 is an inexpensive, easy to use digital circuit breaker analyzer.

The DIGITMR S2 can be operated stand-alone or can be computercontrolled.
It can fully analyze a circuit-breaker’s performance by testing the contact time, stroke, velocity, over-travel, and contact wipe. Contact and motion analysis can be performed for all breaker contact operations (Open, Close, Open – Close, Close – Open, and Open – Close – Open). Timing results are recorded and displayed on the 240 x 128 pixels back-lit LCD screen and can also be printed on the built-in 4.5" wide thermal printer.

“On-line” Timing Mode
In addition to the conventional off-line timing mode, the DIGITMR S2 also offers an optional “on-line” timing mode.

In this mode, the DIGITMR S2 captures the breaker’s trip or close time, the trip/close coil current
“fi ngerprint,” and the battery supply voltage while the breaker is still in service. The trip/close time is derived from the time of trip, or close coil initiation, to the breaker’s bushing current breaker-make as detected by an AC clamp-on current sensing probe.

The “on-line” timing mode can detect a breaker’s operating conditions with little or no down time.

In thismode, the fi rst trip operation time of the breaker is captured.

Open/Close Coil Current Monitoring
A built-in Hall-Effect current sensor records the circuit breaker’s operating coil current amplitude
and duration. The circuit breakers’ operating-coil waveforms (effectively, a performance
“fi ngerprint” or “current profi le”) can be used as a diagnostic tool for analyzing a circuit breaker’s performance.