Vanguard DigiTMR S2 PC - Manual (Page 4)

DIGITMR S2 PC USER’S MANUAL REV 1
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1.0 INTRODUCTION
1.1 General Description and Features
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
“fingerprint,” 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 first 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 first 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 first timing test is conducted.
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 breaker’s operating-coil waveforms (effectively, a
performance “fingerprint” or “current profile”) can be used as a diagnostic tool for analyzing a
circuit breaker’s performance.
Contact Timing Inputs
Dry-contact input channels are used for timing circuit-breaker contacts. Each contact input
channel can detect main contact and insertion resistor contact times in milliseconds and cycles.
Three contact timing channels are available on the DIGITMR S2 PC.
Breaker Stroke and Velocity
One digital transducer input channel is available to measure circuit breaker contact stroke,
velocity, over-travel, and bounce-back. With the use of a Vanguard digital travel transducer, no
set-up calibration is required before testing. A special feature is also available to “Slow-Close”
test a circuit breaker and obtain test results. An optional Resistor Transducer Adapter Device
can be used to interface with any resistor transducer.