In the appendix of Reliability-Centered Maintenance II, John Moubray lists 102 proactive maintenance techniques in six categories:
1. Dynamic effects: monitoring of vibration, pulses and acoustic emissions (17 techniques)
2. Particle effects: monitoring of particles in the component’s operating environment, e.g. lubricant (15 techniques)
3. Chemical effects: monitoring of chemical elements in the component’s operating environment, e.g. lubricant (27 … Read more
From a predictive maintenance perspective, there is little real benefit from taking an oil sample directly from the hydraulic tank. Sure, an oil sample taken from the tank can be used to establish the cleanliness of the hydraulic fluid, and the condition of its base oil and additives.
But these days, most hydraulic systems feature a return filter, and so … Read more
In true AC electric coils, the resistance or impedance of the coil is lowest when the solenoid is open, i.e. when the plunger is out. Impedance increases as the plunger is pulled into the closed position. As a result, the current draw of an AC solenoid is highest when the solenoid is open (plunger out) and lowest when the solenoid … Read more