Serving the Power Industry Since 1980
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Electro-Test and

Maintenance, Inc.

P.O. Box 1527

Rapid City, SD


Protective Relaying Services

Calibration • Testing • Maintenance

Regular inspection and maintenance of relaying is essential in protecting your electrical system from damage due to faults. A peculiar difficulty of protective relays is that the time between operations may be measured in years, during which period defects may have developed unnoticed until revealed by the failure of the protection device to respond to a power system fault.

A quality maintenance and testing program can help reduce mis-operations, nuisance trips, and aid in identifying system coordination issues. The periodic maintenance tests will insure continued reliability, accuracy limits, levels of deterioration of components, correctness in tripping circuit connections, adopted settings and fatal failure of a protective relay.

ETMI can provide installation and setup of Phasor Measurement Unit, (PMU) systems, incorporating RTAC devices if required.

ETMI utilizes computer controlled test equipment to insure the highest level of accuracy and repeatability.