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ekstra   ara
 Post subject: Proper Maintenance
PostPosted: Tue Nov 11, 2014 8:00 am 
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Location: North Carolina
How do define "proper maintenance"?

Three standards out there that I know of:
FM Global Data Sheets.
Some sort of performance standard?

Note that all of the above standards speak to specifically how maintenance is to be done. That is in general or specific terms, what tests, inspections, and routine maintenance are to be done and how often. Manufacturer's guidelines are similar in nature. What we don't have is a guideline as to either how to evaluate (score) a preventive maintenance program, or even to evaluate (score) equipment based on an independent inspection. Yet what NFPA 70E calls for is just what, "proper" maintenance, without defining it.

Presumably one could simply analyze a maintenance/PM program compared to one of the above standards and then generate a score based on the degree of compliance with that standard. However, there are two particular issues with that. The first is that a number of recommended tasks are oriented towards reliability and not necessarily safety as all of the standards are focussed on reliability in general. 70E is not so much concerned with reliability in general as it is with dangerous faults (faults that cause injury directly or exacerbate injury such as by not tripping within specification).

NETA-MTS also requires inputs of environmental condition, so the frequencies are adjusted. However even the lowest PM rates recommended in NETA-MTS exceed any other recommendations I have found and match those of FM Global (that references NETA-MTS). Considering that NETA stands for "National Electrical Testing Association" made up primarily of companies doing electrical testing and that many of the recommended tests have little or no credible value, it would appear that NETA-MTS is a self-serving standard with frequencies designed to drum up business.

What is really troubling here is EPRI Revision 1 of TR-112938, "Routine Preventive Maintenance for AK and AKR Type Circuit Breakers" specifically states in section 2.1, "A common myth among industry personnel is that the manufacturer's guidance must be followed without deviation. Manufacturer's guidance, by their own admission, represents the manufacturer's best generalized advice and includes assumptions about the circuit breaker's environment, lubrication, previous maintenance, and operational history. But without exception, manufacturers encourage plant personnel to identify plant-specific considerations and modify their maintenance intervals as needed. Although deviations from manufacturer's recommendations are acceptable, deviations from these recommendations should be justified and this justification should be documented." do we define "proper maintenance". It's one thing to say it but another to do it.

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