Vanguard108Pg021309:Vanguard 2009 Catalog 2/16/09 10:40 AM Page 38
Accurately
• Inexpensive
• Reliable
• Lightweight
• Easy to Use
Auto-Ohm 100
The Auto-Ohm 100 S2 is Vanguard’s third-generation, microprocessor-based, true DC Connections
micro-ohmmeter. It is designed for testing EHV circuit-breaker contact resistances,
bushing contact joints, or for any low-resistance measuring application. The Auto-Ohm
• 10 to 100 Amperes true continuous DC current
FEATURES
100 S2 can accurately measure resistances ranging from 1 micro-ohm to 300 milli-
• Automatic control of current rise and fall times
ohms. It can output a test current from 10 Amperes to 100 Amperes.
• Digital resistance readings from 1 micro-ohm to 300 milli-ohms
The Auto-Ohm 100 S2 applies a true DC current from 10A to 100A to the resistance load • Stores and can display last 3 readings
to be tested. Any test current setting can be selected by using the function control knob • Weighs less than 21 lbs (9.5 Kg)
on the front panel. The Auto-Ohm 100 S2 controls the test current’s rise and fall rates
by using a switching DC power supply and a current regulator circuit. An Auto Test
Mode is also available and can be initiated simply by applying the sensor cables’ leads
across the two points of interest. This feature is very convenient when measuring a
sequence of several resistance values in a breaker contact.
Since a true DC ramped current is passed through the breaker contacts, no magnetic
transient is induced into the breaker’s current transformer. This can prevent the risk of
inductively tripping a breaker control (bus differential relay). The resistance reading is
displayed directly in micro-ohms or milli-ohms. No calculations are required to com-
pensate for lead resistances when using the Auto-Ohm 100 S2.
Accessory Clamps
and Handspike
The Auto-Ohm 100 S2 features a back-lit LCD screen (1-inch high, 16 characters by 2
lines) that is viewable in both bright sunlight and low-light levels. The resistance read-
ing is displayed on the screen until the next test is initiated. The last three resistance Ordering Information
measurements are stored internally and can be displayed on the LCD screen. An RS- Auto-Ohm 100 Series 2 True DC Micro-ohmmeter
232C interface port is also provided for factory calibration and diagnostic testing.
AUTO-OHM 100 S2 & 30-ft Test Cable Part No: AUTO-OHM 100 S2
The Auto-Ohm 100 S2 is furnished with two 30-foot test cables. Fifteen-foot test cables AUTO-OHM 100 S2 Carrying Case Part No: AUTO-OHM 100 S2 Case
15-foot Test Cable Part No: AUTO-OHM S2 Cable-15ft
are also available as an option. Both cables are terminated with quick disconnect clips.
30-foot Test Cable Part No: AUTO-OHM S2 Cable-30ft
Heavy-duty, welding-type, C-clamps are available as an optional accessory. These can C-Clamp Set (2 clamps) Part No: AUTO-OHM S2 C-Clamps 30ft
be used to connect the test cable leads to a wide variety of bushing sizes, bus-bars and Handspike Set (2 probes) Part No: Handspike
other conductors requiring low-resistance test contacts.
True DC Micro-ohmmeter
2
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Vanguard108Pg021309:Vanguard 2009 Catalog 2/16/09 10:40 AM Page 39
y Measure Resistance from
1 micro-ohm to 300 milli-ohms
RS-232C Interface
High Current Presence Indicator
Built-in Circuit Breaker
Back-lit LCD Screen
(16 characters by 2 lines)
Function Control Knob
Sensing Lead Connector
Current Lead Connector
SPECIFICATIONS
TYPE Portable micro-ohmmeter
PHYSICAL SPECIFICATIONS 16.8”W X 12.6”H x 12.0”D (42.7 cm x 32.0 cm x 30.5 cm); Weight: less than 21 lbs (9.5 kg)
INPUT POWER 100 – 240 Vac, 50/60 Hz
RESISTANCE READING RANGE 1 micro-ohm – 300 milli-ohms (1 micro-ohm resolution); Accuracy: ±1% reading, ± 1 count
TEST CURRENT RANGE Thermally-protected DC power supply, 10 Amperes – 100 Amperes
TEST DURATION 5 seconds – 120 seconds, selectable
DISPLAY 1-inch high back-lit LCD Screen (16 characters by 2 lines); viewable in bright sunlight and low-light levels
INTERNAL TEST RECORD STORAGE Stores and can display last 3 readings
COMPUTER INTERFACE RS-232C port (19,200 Baud) for factory calibration and diagnostics
SAFETY Designed to meet IEC61010 (1995), UL61010A-1, CSA-C22.2 standards
ENVIRONMENT Operating: -10°C to 50° C (15°F to +122° F); Storage: -30° C to 70° C (-22°F to +158° F)
CABLES 30-foot (#1AWG) test cables, ground cable, power cord
OPTIONS Transportation case, 15-foot test cables, C-clamps, Handspike
WARRANTY One year on parts and labor
Note: The above specifications are valid at nominal voltage and ambient temperature of +25°C (+77°F). Specifications are subject to change without notice.
Vanguard Instruments Company
Reliability Through Instrumentation
Vanguard Instruments Company, Inc.
Vanguard Instruments Co., (VIC), was founded in 1991.
Currently, our 28,000 square-foot facility houses
Administration, Design & Engineering, and Manufacturing
operations. From its inception, VIC’s vision was, and is to
develop and manufacture innovative test equipment for
use in testing substation EHV circuit breakers and other
electrical apparatus.
The first VIC product was a computerized circuit-
breaker analyzer, which was a resounding success. It
became the forerunner of an entire series of circuit-
breaker test equipment. Since its beginning, VIC’s
product line has expanded to include microcomputer-
based, precision micro-ohmmeters, single and three-
phase transformer winding turns-ratio testers, wind-
ing-resistance meters, transformer tap-changing con-
trollers, megaohm resistance meters, and a variety of
other electrical utility maintenance support products.
VIC’s performance-oriented products are well suited
for the utility industry. They are rugged, reliable, accu-
rate, user friendly, and most are computer controlled.
Computer control, with innovative programming, pro-
vides many automated testing functions. VIC’s instru-
ments eliminate tedious and time-consuming opera-
tions, while providing fast, complex, test-result calcu-
lations. Errors are reduced and the need to memorize
long sequences of procedural steps is eliminated.
Every VIC instrument is competitively priced and is
covered by a liberal warranty.
Vanguard Instruments Company, Inc.
1520 S. Hellman Ave. • Ontario, California 91761 USA • P 909-923-9390 • F 909-923-9391
www.vanguard-instruments.com
