Switchgear Maintenance and Condition Monitoring
Insulation systems for metal enclosed switchgear are normally designed with life expectancy of approximately 20-30 years. However certain factors such as moisture, dirt and corrosive atmosphere can reduce the life span of such a system. Thus it is a necessity to conduct switchgear maintenance and monitor the condition of the insulation by routine testing. These tests can be either AC or DC depending on the standard being used.
Elements such as bus bars, CBs, disconnections form part of the switchgear and they represent the central part of electrical energy grids. This article focuses on the importance carrying out maintenance on breakers
Circuit Breakers: One of the most important tests to determine the real condition of a circuit breaker is to carry out timing measurements. These tests fulfill all the requirements defined by IEC62271-100 and IEEE C37.09. DV Power’s CAT II series is an example of an analyser that meets international standards’ requirements\
Figure 1: CAT II Circuit Breaker analyser
Features:
· Robust design for field use
· Accurate measurement in high voltage environment
· Timing and motion measurement
· Built in micro ohmmeter (up to 500 A)
· Dynamic resistance measurement
· Detailed analysis of test results using DV-Win software etc.
Also available in the market are hand held circuit breaker analyzers (CAT-P). These are digital instruments which are used for offline and online testing of circuit breakers – onsite analysis of circuit breaker defects for immediate attention. They can also be utilised for evaluating the state of the substation’s battery by presenting the voltage value numerically and graphically
Figure 2: CAT-P connection for online measurement
Note: Online measurements can be performed by a single operator in about 10 minutes.
Features:
· Acquisition and analysis of test results
· Downloading the test results from CAT-P to PC
· Viewing and overlaying several graphs for an easy test result comparison etc.
For more inforation please send your request to [email protected]