• dry-contact inputs 3 dry-contact channels
• timing windows 1 second, 10 seconds, or 20 seconds
• timing resolutions ±50 micro-seconds @ 1 sec. duration
• Inexpensive, PC-controlled EHV circuit breaker analyzer
• Optional "on-line" timing mode
• Small and light-weight
• Can test contact time, stroke, velocity, over-travel, and contact wipe

The Vanguard DIGITMR S2 PC is an inexpensive, easy to use digital circuit breaker analyzer that is designed to be used with a PC. This inexpensive analyzer offers the most cost-effective method for testing circuit breakers. It can fully analyze a circuit-breaker’s performance by testing the contact time, stroke, velocity, over-travel, and contact wipe. Contact-motion analysis can be performed for all breaker contact operations (Open, Close, Open – Close, Close – Open, and Open – Close – Open). The DIGITMR S2 PC offers three dry-contact channels (for timing circuit breaker main and insertion resistor contacts), one digital transducer channel (to monitor CB contact motion), and two voltage monitoring channels.

“On-line” Timing Mode Option

An optional “on-line” timing mode is available for

the DIGITMR S2 PC. In this mode, the DIGITMR S2

PC 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

this mode, the fi rst trip operation time of the breaker

is captured. If a breaker has been in service for a long

period of time and sitting in close position, the fi rst

trip time of the breaker may be slow possibly due to

a sticky mechanism. The “on-line” mode is very useful

in such cases because traditional breaker timing

may not detect this condition since several operations

may have occurred before the fi rst timing test

is conducted.

CB Analysis Software

The DIGITMR S2 PC comes with the

Windows®-based Vanguard Circuit Breaker

Analyzer Series 2 (VCBA S2) software. This

software is used to perform circuit breaker

timing tests from the PC and to create test

plans for specifi c circuit breakers.

A test plan comprises of all circuit breaker

performance specifi cations (Stroke, Velocity,

and Contact Time). When a test plan is used

to perform a test, the DIGITMR S2 PC compares

the test results with the circuit breaker's

performance defi ned in the test plan to generate

a “Pass/Fail” report

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.

Part number DIGITMR S2 PC DIGITMR S2 PC, cables, and PC software

Part number DIGITMR S2 PC-CASE DIGITMR S2 PC shipping case

Part number DIGITMR S2 PC-ONLINE TIMING DIGITMR S2 PC on-line timing mode option

Part number Paper-TP4 thermal printer paper