The Vanguard Auto-Ohm-200 S3 is a microprocessor-based, true DC micro-ohmmeter. It is designed for testing EHV circuit-breaker contact resistances, bushing contact joints, welding joints, or for any low-resistance measuring application. This high current and very lightweight (16.8 lbs/ 7.6 Kg) micro-ohmmeter is designed to meet the IEEE C57.09-1999 (5.15) requirement for testing circuit breaker contact resistance.
The Auto-Ohm-200 S3 can accurately measure resistance values from 1 microohm to 5 ohms. A 0.1 micro-ohm resolution is possible with current greater than 5A. The Auto-Ohm-200 S3 applies a selectable true DC test current from 1A to 200A to the resistance load to be tested.
The Auto-Ohm-200 S3 controls the test current’s rise and fall rates. The test current rise and fall rate can be selected from 5 seconds to 30 seconds. An “Auto Test” mode is also available and can be initiated simply by applying the sense cables’ leads across the two points of interest in the current path. This feature is very convenient when measuring a sequence of several resistance values in a circuit breaker contact.
The Vanguard Auto-Ohm 200 S3 can also compare test results against preset limits and determine if a test passed or failed, and a “Pass” or “Fail” fl ag is displayed accordingly. Since a true DC current (with controlled rise/ fall time) is passed through the circuit breaker contact, no magnetic transient is induced into the breaker’s current transformers. This feature greatly reduces the risk of inductively tripping a breaker control (bus differential relay).
Vanguard Auto-Ohm 200 Specs
||Dimensions: 17" W x 7" H x 13" D (43.2cm x 17.8cm x 33cm)
Weight: 16.8 lbs (7.6 Kg)
||100 – 240 Vac, 50/60 Hz
|Resistance Reading Range:
||10 milliohms at 200A to 5 ohms at 1A
1A to 4.99A: 1% ±10 micro-ohms
5A to 9.99A: 1% ± 2 micro-ohms
10A to 200A: 1% ± 1 micro-ohm
|Test Current Range:
||1 Ampere to 200 Amperes (selectable in 1A steps);
Thermally protected DC power supply.
||Back-lit LCD (128 x 64 pixels), viewable in direct sunlight and low light levels
||Rugged, 44-key "QWERTY" membrane keypad
|Internal Test Record Storage:
||128 test records. Each record can contain up to 64 readings.
|External Test Record Storage:
||Up to 999 test records on external USB Flash drive
||Windows XP/Vista/7 Analysis Software (included with purchase)
||Designed to meet IEC 61010 (1995), UL 61010-a, and CAS-C22.2 standards
||Operating: -10ºC to 50ºC (15ºF to +122ºF)
Storage: (-30ºC to 70ºC (-22ºF to +158ºF)
||90% RH @ 40˚ C (104˚ F) non-condensing
||2000m (6562 ft) to full safety specifications
||30 ft (9.1 m), #1 AWG test cables, power cord, ground cable
||Shipping case, 15 ft test cables, C-Clamp set, Hand Spike Set