5 typical motor faults: how ESA finds them in 7 minutes

At an industrial plant more than 60% of unplanned auxiliary equipment stoppages involve motors and drives. Vibration analysis solves part of the problem, but it needs access to the shaft, sensors and a qualified analyst. Electrical Signature Analysis (ESA) — analysis of current and voltage in the power cable — reveals mechanical and electrical faults without stopping the machine and without sensors on the housing.

Artesis AMT Pro (route-based diagnostics) and Artesis e-MCM (online monitoring) use ESA and produce a verdict in 5–7 minutes per machine.

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1. Rotor unbalance and eccentricity

Symptoms on site: elevated vibration, accelerated bearing wear, noise at running speed.

What ESA sees: characteristic sidebands around the supply frequency (50 Hz), proportional to rotational speed. When the rotor is eccentric relative to the stator, additional components appear that differ from pure unbalance.

In practice: on mining conveyors take-up pulley unbalance often masquerades as a "bearing problem". ESA separates the mechanical causes without stripping the drive.

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2. Bearing wear

Symptoms: growing noise, local heating and, in extreme cases, rotor seizure.

What ESA sees: current modulation at frequencies related to bearing geometry (BPFO, BPFI, BSF, FTF). The Artesis algorithm matches the signature against a base of 10+ million reference faults.

Advantage over vibration: no access to the bearing housing is needed — the control cabinet is enough. That is especially valuable for submersible pumps, where fitting a vibration sensor is difficult.

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3. Mechanical looseness (bolts, feet, foundation)

Symptoms: "floating" vibration, phase wander, periodic impacts.

What ESA sees: amplitude and phase instability of current components, typical of a loose stator mounting or base. Often combined with unbalance after a rushed repair.

Combining with SDT: ultrasound on the SDT340 catches looseness early through friction acoustics — see SDT + Artesis integration.

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4. Stator winding faults

Symptoms: overheating, efficiency drop, protection trips, smell of insulation.

What ESA sees: phase asymmetry, rising harmonics, signs of inter-turn shorts and insulation weakening before thermal destruction.

For CHP and metals plants: auxiliary pumps and fans with frequent starts are especially vulnerable. Online e-MCM monitoring gives a trend and an alert months before failure.

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5. Rotor faults (bars, end rings, slip rings)

Symptoms: torque pulsation, jerking, unstable current at constant load.

What ESA sees: sidebands at slip frequency — the fingerprint of damaged bars or slip rings.

On mills and crushers this is one of the most expensive failures. The mining mill monitoring case shows how ESA detects a rotor fault while vibration still looks normal.

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Comparison: route vs online

Task	Instrument	When
Survey 50+ machines in a shift	AMT Pro	Start of a PdM programme, fleet audit
Critical drives 24/7	e-MCM	After the pilot on key machines
Several sites	Artesis IoT	Centralising the data

More about phased rollout — in "A three-tier PdM strategy: AMT → e-MCM → IoT".

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Where to start at a plant in Kazakhstan

1. Draw up a list of critical motors (downtime = a section stops).
2. Run an AMT Pro route — 7 minutes per machine, no shutdown.
3. Launch a 90-day e-MCM pilot on the 3–5 worst machines — step-by-step plan.
4. Complete the programme with an SDT ultrasound route for bearings, steam lines and leaks — SDT + Artesis roadmap.

KEG TRK is the official supplier of Artesis and SDT in Kazakhstan. For an AMT Pro demonstration on your equipment: info@keg-trk.kz, +7 (7172) 64-08-69.