Vanguard DigiTMR - Manual (Page 8)

DIGITMR USER’S MANUAL REV 3
3
Analog Voltage Monitoring Channel
One analog voltage monitoring channel, designated as “V1”, is dedicated to monitoring
the breaker’s DC power supply, or coil voltages from 0 to 255 Vdc or peak Vac. Test
results can be printed and include nominal voltage (when the supply voltage has no
load), and minimum voltage (when the supply voltage is under load or when a coil is
energized).
The “V1” connection can also monitor the DC power supply’s voltage fluctuations during a
breaker operation. This feature is effective in detecting breaker power supply problems that
normally cannot be detected using a voltmeter.
Digital Voltage Monitoring Channel
One digital voltage monitoring channel, designated as “V2”, monitors the status
voltage as “ON” or “OFF”. Voltages from 30 to 255 Vdc are considered “ON”, whereas
voltages less than 30 Vdc are considered “OFF”. This input channel is dedicated to
monitoring the breaker’s auxiliary switch action during a breaker operation. Input
voltage range is from 1 to 300 Vac/dc.
External Trigger Input Channel
The external trigger input can be used to trigger timing functions when the DigiTMR
senses a voltage. Voltage levels can range from 30 to 300 Vdc or peak Vac. Different
trigger voltages can be set at the factory per specific requests from users.
Travel Transducer Input Channel
The DigiTMR features one digital transducer input channel. It can interface with
linear and rotary transducers as well as with special transducers developed by
Vanguard Instruments Company, Incorporated. Transducers offered by
Vanguard include 10-inch, 25-inch, and 30-inch linear transducers, a 15-inch
universal transducer, a rotary transducer, an ABB AHMA-8 type transducer, an
ABB AHMB type transducer, and a Westinghouse SF/SFA type transducer.
Please see Appendix F for transducer illustrations.
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 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 3.9 for further information about test plans.