Is there a general rule for oil sampling frequency for "standby" equipment? The machines in question are our standby emergency cooling pump motots that generally run for only 5-10 hours per month. For our nuclear friends what is your frequency of sampling on your RHR/Core Spray/Decay Heat Removal/Containment Spray pump motors? Based on run time alone you would sample about once every 10 years or so. That isn't good.
rgf

My sample frequency for standby safety-related components is quarterly.

The routine sample is obtained during operation or within 15 minutes of shutdown, depending on the arrangement of the machine or other limitations.

Non-routine or diagnostic samples would be collected each surveillance, or, as appropriate.

I agree with your assessment of sample vs run time issue. However, we have to base the actual frequency on numerous inputs (mission of the equipment/run to failure or not, regulatory requirements, capital cost of replacement, loss of production, personnel safety, OEM recommendations, warranty requirements, accessiblility to the component, etc to name a few)

Hope this helps.