Motor circuit analyzer
Updated 2026-10-27
Data records
- The de-energized (static) test reads the resistance, impedance, inductance, phase angle and current-frequency response of the windings and the insulation to ground, and from them diagnoses stator, rotor, ground and contamination faults.
- A motor circuit analyzer is a portable instrument that assesses the electrical condition of a motor and its supply circuit; combined designs make de-energized tests on the stationary motor and energized tests while it runs, in one package.
- The energized (dynamic) test is made while the motor runs and reports power quality, current analysis, torque, efficiency and machine performance, and spectrum analysis of the current reveals broken rotor bars and bearing faults.
- Analysis is organized into six fault zones, the stator, rotor, air gap, insulation, power circuit and power quality, and the instrument reports data for each zone.
- A single de-energized three-phase test can be reduced to one machine-health value that is trended over successive tests; a deviation or fluctuation in the value marks the motor for closer troubleshooting.
- An analyzer with a high-voltage insulation source also performs the resistance-to-ground, polarization index and step-voltage insulation tests at a test voltage selected on the instrument.
- Torque and transient analysis of the energized readings separates electrical problems from mechanical ones such as misalignment, imbalance, cavitation and bearing degradation.
- Energized testing is made with the motor in service, so the stator, rotor, air gap, power circuit and power quality are assessed without interrupting production and shutdowns are reserved for the motors that need them.
- The static test is made from the motor's drive or starter rather than at the machine, so the cables and connections between them are evaluated along with the motor windings.
Elsewhere in the family
- Motor Current Signature Analysis related entry on Motor Testing Reference
- Motor Run Test Under Load related entry on Motor Testing Reference
Sources
- ALL-TEST Pro product page, Induction Motor Testing Equipment | ALL-TEST PRO 7 Pro, web page edition, ALL-TEST Pro. Held as: Public page. Publisher page
- ALL-TEST Pro product page, Motor Condition Monitoring Device | ALL-TEST PRO 34, web page edition, ALL-TEST Pro. Held as: Public page. Publisher page
- Megger product page, Baker EXP4000 dynamic motor analyzer, web page edition, Megger. Held as: Public page. Publisher page
- PdMA product page, MCEMAX, web page edition, PdMA. Held as: Public page. Publisher page
- PdMA product page, EMAX, web page edition, PdMA. Held as: Public page. Publisher page
Changelog (23 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (instr.motor-circuit-analyzer.de-energized-measurands) | |
| 2026-10-27 | revised (instr.motor-circuit-analyzer.de-energized-measurands) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.de-energized-measurands) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.definition) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.energized-tests) | |
| 2026-10-27 | revised (instr.motor-circuit-analyzer.energized-tests) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.energized-tests) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.fault-zones) | |
| 2026-10-27 | revised (instr.motor-circuit-analyzer.fault-zones) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.fault-zones) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.health-value-trending) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.health-value-trending) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.insulation-tests) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.insulation-tests) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.mechanical-vs-electrical) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.mechanical-vs-electrical) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.online-no-shutdown) | |
| 2026-10-27 | revised (instr.motor-circuit-analyzer.online-no-shutdown) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.online-no-shutdown) | |
| 2026-10-27 | created (instr.motor-circuit-analyzer.test-from-mcc) | |
| 2026-10-27 | revised (instr.motor-circuit-analyzer.test-from-mcc) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.motor-circuit-analyzer.test-from-mcc) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Motor circuit analyzer." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/instruments/motor-circuit-analyzer/.
Test Instrument Reference, Motor circuit analyzer (Oct. 27, 2026), https://www.testinstrumentreference.com/instruments/motor-circuit-analyzer/.
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title = {Motor circuit analyzer},
howpublished = {\url{https://www.testinstrumentreference.com/instruments/motor-circuit-analyzer/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=Motor circuit analyzer |website=Test Instrument Reference |publisher=Test Instrument Reference |url=https://www.testinstrumentreference.com/instruments/motor-circuit-analyzer/ |date=2026-10-27 |access-date=}}