What Is Condition Monitoring and Why It Pays for Itself

The shift from reactive to predictive

For decades, industrial maintenance ran on two modes: run-to-failure (reactive) and time-based planned maintenance (preventive). Both are expensive. Reactive maintenance costs 3–5× more than planned work, and time-based schedules cause unnecessary change-outs of perfectly healthy components.

Condition monitoring — sometimes called predictive maintenance — changes the economics. By continuously measuring vibration, temperature, and electrical current on critical assets, you can detect the early signatures of bearing wear, imbalance, misalignment, and winding degradation weeks before they become failures.

The three signals that matter

Vibration

Every rotating asset has a baseline vibration signature. Faults change that signature in predictable ways:

• Bearing wear shows up as high-frequency harmonics in the 1–10 kHz band.
• Imbalance produces a strong 1× RPM component.
• Misalignment produces a 2× RPM harmonic.
• Looseness produces a 3× or higher harmonic.

A single tri-axial accelerometer on the bearing housing catches all of these.

Temperature

Surface temperature on the bearing housing or gearbox casing is a lagging indicator — but a reliable one. A sustained 10–15°C rise above baseline over days almost always means friction, lubrication loss, or overload. Temperature monitoring on a gearbox caught one Howcroft customer a £12,000 gearbox seizure for a £500 seal replacement.

Three-phase current

Electrical faults are invisible to vibration sensors. Three-phase current monitoring detects:

• Winding insulation degradation (asymmetric current draw)
• Soft-starter and capacitor-bank failures (in-rush spikes)
• Overload and under-load conditions

One Howcroft customer was about to replace a £28,000 motor. Current monitoring proved the motor was healthy — the fault was a £350 capacitor bank in the soft starter.

The ROI

Industry studies (McKinsey, Deloitte) put the average ROI of condition monitoring at 10×–30× the annual monitoring cost, driven by:

• 70% reduction in unplanned failures
• 25–30% reduction in reactive maintenance spend
• 12% energy savings from eliminating motor inefficiency
• Elimination of secondary damage (a £200 bearing caught early prevents a £4,000 motor replacement)

Use our ROI calculator to model your own site.

Getting started

You don't need to monitor every asset. Start with your critical few — the assets whose failure halts production or carries a high replacement cost. A typical first deployment covers 10–30 assets and pays back within the first quarter.

Book a free site survey and we'll identify your highest-risk assets.