NOTE:
Complete configuration of InsightCM™ devices and asset trees is performed within the InsightCM™ application. Refer to the InsightCM™ Setup and Configuration Manual (available at https://support.cutsforth.com) for full device configuration procedures. This section covers the ESA-specific configuration items required before monitoring can begin.
Accurate configuration is the foundation of reliable ESA monitoring. Because every fault feature is calculated relative to the motor's rated operating point and scaled from the signals the device measures, the analysis is only as accurate as the configuration behind it.
The following nameplate fields are required before feature calculation can begin:
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Load and Load Unit (HP or kW)
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Nominal Frequency (50 or 60 Hz)
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Synchronous Speed (RPM)
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Full Load Speed (RPM)
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Rated Volts
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Full Load Amps (FLA)
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Service Factor
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Power Factor
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Full Load Efficiency
The following fields are optional but improve analytical accuracy and should be entered where available:
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Efficiency at 75% Load
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Efficiency at 50% Load
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Efficiency at 25% Load
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Number of Stator Slots
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Number of Pump Vanes / Fan Blades
-
Number of Rotor Bars
Nameplate data can typically be found on: the motor nameplate, spare motor nameplate, motor/pump manuals, previous test reports, CBM/PdM databases and reports, and relay/protection documents.
NOTE:
Use the asset tree's invalid-configuration markers in InsightCM™ to confirm that no motor group is missing required nameplate information before placing assets into routine monitoring.
The ESA device measures the stepped-down secondary signals from the potential transformers (PTs) on the voltage bus and the current transformers (CTs) on each motor phase. InsightCM™ must be told the ratio of each transformer so that it can scale these secondary measurements back to the true primary voltages and currents.
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CT ratio: Expresses primary-to-secondary current. For example, a 200:5 CT outputs 5 A on the secondary when 200 A flows in the primary.
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PT ratio: Expresses primary-to-secondary voltage. For example, a 4160:120 PT outputs 120 V on the secondary when 4160 V is present on the primary.
WARNING
If a CT or PT ratio is entered incorrectly, every voltage- or current-derived feature — RMS, power, power factor, percent load, and unbalance — will be scaled incorrectly even though the waveform shape appears correct. The entered ratios must exactly match the nameplates of the installed transformers.
When the voltage bus is created in InsightCM™, the associated PT sensors are added, and the wiring configuration must be defined to match the installation. Select the appropriate configuration:
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Wye or Delta bus topology
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Number of voltage sensors (typically two or three sensors per bus)
The selected configuration determines how phase-to-phase and phase-to-ground relationships are interpreted. Where multiple motors share a common voltage source, a shared voltage bus configuration can be created once and applied to each motor fed from that bus.
After entering nameplate data, transformer ratios, and wiring configuration, verify the installation using the Phasor Diagram in InsightCM™ before placing the asset into routine monitoring.
With an induction motor, current should lag voltage. Confirm the following:
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The three voltage phasors are balanced in magnitude and spaced approximately 120° apart.
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The three current phasors are balanced in magnitude and spaced approximately 120° apart.
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Each current phasor lags its associated voltage phasor.
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The phase sequence is correct (A matched to A, B to B, C to C).
NOTE:
If a current phasor appears 180° out of phase with its associated voltage phasor, the current sensor polarity is reversed. This can be corrected in InsightCM™ by enabling the Reverse Polarity setting for that phase in the asset configuration page and pushing the updated configuration to the device — no physical field changes are required.
Alarm thresholds for ESA assets are based on a combination of industry standards, operational experience, and equipment-specific trend data. Thresholds should be reviewed and tuned periodically. The primary reference standard is ANSI/NEMA MG 1, Motors and Generators.
|
Parameter |
Recommended Alarm Window |
Notes |
|---|---|---|
|
Voltage Unbalance |
3% – 5% |
Per NEMA MG 1, motors should be derated above 1% unbalance. Operating within 3%–5% is acceptable with derating. |
|
Current Unbalance |
5% – 8% |
Provides early warning before current exceeds service-factor limit. Can indicate voltage unbalance or impending stator fault. |
|
Torque Ripple |
Greater than 10% |
Excess torque ripple historically indicates developing driven-equipment issues such as pump problems. |
|
Rotor Bar Sideband |
Greater than -45 dB: low concern; greater than -40 dB: moderate; greater than -35 dB: high |
Values are negative dB; less-negative is worse. Tune thresholds per asset and load class. |
NOTE:
In addition to fixed thresholds, consider configuring deviation-from-baseline alarms. Once a representative healthy signature is established for an asset, alarms configured on statistical deviation from that baseline can detect small step changes earlier than traditional fixed-setpoint alarms.
The ESA system uses configurable operating states to gate data collection and feature calculation based on motor load. The default operating states are:
|
State |
Entry Condition |
Data Collection |
Notes |
|---|---|---|---|
|
Off |
% FLA less than 25% |
Trend: every 5 min; Data set: once per hour |
Full fault feature calculation not performed; motor not running under sufficient load. |
|
Default (Running) |
% FLA 25% to less than 200% |
Trend: every 5 min; Data set: once per hour (3 sec, with 1 sec pre-trigger) |
Normal monitoring state; full fault feature calculation is active. |
|
Startup |
% FLA 200% or greater |
Single 30-sec data set (with 1 sec pre-trigger) |
Captures full startup transient. Exits when % FLA drops below 110% for 5 sec or after 30 sec. |
NOTE:
The minimum working current threshold (default 25% FLA) and maximum working current threshold (default 200% FLA) are configurable on the Device Properties tab in InsightCM™. The Rotor Bar Sideband feature returns -100 dB when the motor is below the minimum working current threshold.