SACA Predictive Maintenance and Condition Monitoring

Question 1

What is the key difference between Predictive Maintenance (PdM) and Preventive Maintenance (PM)?

Accepted Answer

PdM uses real-time condition data to service equipment only when degradation is detected; PM services equipment on a fixed time or cycle interval regardless of condition

Answer

Predictive Maintenance monitors actual equipment condition (vibration, temperature, oil quality) and triggers maintenance only when indicators approach failure thresholds, avoiding unnecessary work. Preventive Maintenance follows a calendar or run-hour schedule regardless of actual equipment health, which can lead to over-maintenance.

Question 2

A maintenance technician uses a vibration analyzer and finds a dominant frequency peak at exactly 1× running speed. This signature most likely indicates:

Accepted Answer

Mass imbalance in the rotating component

Answer

A dominant vibration peak at 1× running speed (1× RPM) is the classic signature of mass imbalance — the center of mass is offset from the center of rotation, creating a once-per-revolution centrifugal force. Bearing defects produce sub- or super-harmonic frequencies; gear mesh appears at (teeth × RPM) frequency.

Question 3

Infrared thermography is used in a PdM program primarily to detect:

Accepted Answer

Abnormal heat patterns indicating electrical resistance problems, bearing failures, or refractory degradation

Answer

Infrared thermography detects thermal anomalies non-intrusively. Hot spots on electrical panels indicate high-resistance connections; elevated bearing temperatures signal lubrication failure or wear; cold spots in refractory lining reveal thermal breaches. It is a key non-contact PdM tool.

Question 4

What does the P-F curve in predictive maintenance represent?

Accepted Answer

The interval between the point where a potential failure (P) can be detected and the point of functional failure (F)

Answer

The P-F curve shows that most failures don't happen instantaneously — a detectable degradation signal (P) appears well before actual functional failure (F). The P-F interval is the window available for PdM intervention. Monitoring technologies must detect the failure at the P point to allow planned maintenance before F.

Question 5

Oil analysis as a PdM technique is BEST suited for detecting which type of equipment problem?

Accepted Answer

Internal wear, contamination, and lubricant degradation in gearboxes and hydraulic systems

Answer

Oil analysis detects wear metals (iron, copper, chromium particles) that indicate internal component wear, identifies contaminants (water, dirt, coolant), and measures lubricant properties (viscosity, TAN/TBN) to assess whether the oil is still serviceable — ideal for gearboxes, hydraulic systems, and compressors.

SACA - Smart Automation Certification Alliance Practice Test

SACA - Smart Automation Certification Alliance Practice Test

SACA Predictive Maintenance and Condition Monitoring