The DMOM-600 can accurately measure resistance values from 1 micro-ohm to 450 milliohms. A 0.1 micro-ohm resolution is possible with current greater than 10A. The DMOM-600 applies a selectable true DC test current from 10A to 600A to the resistance load to be tested and 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 DMOM-600 can also compare test results against preset limits and determine if a test passed or failed, and a “Pass” or “Fail” flag is displayed accordingly.
The DMOM-600 is specifically 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 (33 lbs/ 15 Kg) micro-ohmmeter is designed to meet the IEEE C57.09-1999 (5.15) requirement for testing circuit breaker contact resistance.
Presenter: Linda Nowak, Principal Engineer, Doble Engineering Company
Linda Nowak is a Principal Engineer for Doble Engineering. She previously has 13 years experience working for Northern States Power and Xcel Energy. During her time at these utilities she spent time in Electric Maintenance, Substation Engineering and Power Plant Engineering and Maintenance. At Doble and Northern States Power she compiled extensive experience in the area of diagnostic testing and condition assessment. While at Doble she has published several papers on various power equipment topics. She is currently the secretary of the Doble Bushing, Insulator, and Instrument Transformers Committee. Ms. Nowak has a B.S. in Electrical Engineering from the University of Minnesota. She is an IEEE member and Licensed Professional Engineer in the State of Minnesota.