Vanguard DigiTMR S2 - Manual (Page 8)

DIGITMR S2 USER’S MANUAL REV 1
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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.
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.
In Time Travel Mode, the digital transducer measures the breaker stroke, over-travel, bounce
back, contact wipe, and contact velocity. Breaker contact velocity calculations are based upon a
contact’s travel distance over a period of time, which is defined by the manufacturer’s
specifications. The DigiTMR S2 not only calculates simple distance-over-time velocities, but also
supports other formulas. An example is a Siemens SPS2 breaker velocity calculation formula
shown below:
V = 12.2 x a/b
The formula and analysis points can be stored in a test plan for later use in the field. Please see
section 3.11 for further information about test plans.
NOTE
If a breaker test plan is used during testing, test results are compared with the
specifications in the test plan, and a “Pass” or “Fail” indicator is printed on the test
report based on the results of this comparison.
CT Input
One non-contact AC current sensor is used to monitor circuit breaker on-line current for the
“on-line” timing mode.
Voltage Monitoring Input
One analog input channel, designated as (V1), is dedicated to monitoring the substation DC
supply or coil voltage (0-255 Volts, DC or peak AC). A second voltage input channel, designated
as V2, is dedicated to detecting voltage On/Off status (presence or absence). This input can be
used to monitor the status of an A/B switch.
Circuit Breaker Initiate Feature
A built-in solid-state initiate device is used to operate the circuit breaker from the DigiTMR S2.
Operational modes include Open, Close, Open-Close, Close-Open, and Open-Close-Open.
Multiple operations such as Open-Close, Close-Open, and Open-Close-Open can be initiated
using a programmable delay or by sensing the circuit breaker’s contact condition. The circuit
breaker coil current amplitudes and waveforms are recorded and can be printed on the thermal
printer.