Condition-based maintenance principles

The electric utility industry is today forced by the Market Directive to adopt condition-based maintenance to ensure steady supply. The method universally adopted to ensure proper installation of cable system accessories and to periodically determine the state of the insulation for decision making about repairing or replacing before failure occurs is partial discharge (PD). This method is based on the time-of-flight principle of induced PD signals a time variation is attributed to local faults. Calibration is needed to establish a correct relationship between the magnitude... 

Chadha, S., Poster-Miller s On-Line Oil Condition Monitor, A Cost-Effective Cross-Platform Tool for Condition-Based Maintenance , Lubr. Fluid Power J. 1, 26-30, Nov 2000. Jacobs, Kenneth S., Applying RCM Principles in the Selection of CBM-Enabhng Technologies , Lubr. Fluid Power J.1, 5-14, Nov 2000. 

A new maintenance system is introduced based on the new mantra for the selection of all equipment Life Cycle Cost. This new system especially for major power plants is based on the combination of total condition monitoring, and the maintenance principles of total productive maintenance, and is called the Performance Based Total Productive Maintenance System. ... 

Other criteria related to relevance like operating and maintenance conditions must also be taken into account. The first principle of data selection in ISO20815 also mentions identical equipment models. If this is the case and operating and maintenance conditions also are the same, the relevance is obviously high. However, usually the data source contains a mix of many different equipment manufacturers and models which are unknown. It is rather the exception that the analyst has access to much data for the one particular equipment model of interest. If this condition is not fulfilled, it can be argued that relevance may still be high if equipment can be defined as similar based on other factors. 

Beyond the detection of a latent failiue, there must be a sanction whose performance must be based on simple concepts (and therefore easily demonstrable). The sanction can be viewed in two stages immediate safety (instantaneous behavior of the architecture) and secmely maintaining the fallback position. Immediate safety limits the spread of crash scenarios. This action can be ensinod by probabilistic safety , as is the detection of the failme. In contrast, the maintenance in a secure condition can only be guaranteed by the principles of intrinsic safety. The PIPC cuts off the output power supply with an intrinsic safety watchdog mechanism, based on safety relays (using gravity). 

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