AEP has the expertise to test large motors and generators through predictive maintenance testing and standard accelerated aging and evaluation tests for high voltage systems.

Predictive Maintenance testing using Electro magnetic interference (EMI) signature analysis. Any electrical insulation that is under duress tends to exhibit partial discharge, which in turn creates EMI, a broadband electrical noise signal that can be easily monitored and trended.  Using frequency selective techniques, signature patterns for several dozen discrete conditions have been developed.   We bring our services to you in our EMI Test Van. Our online, non-intrusive and predictive maintenance testing not only monitors the targeted  machine but also anything else connected to it.

We can identify a variety of conditions that can alert you to numerous issues, from minor partial discharge to an impending major overhaul. Whether you have loose connections on bus work, a failed switch or failing bearings, our portable instrumentation can help you find it. 

  - Accelerated Aging & Evaluation Tests
  - Voltage Endurance
  - Dissection
  - Dielectric Breakdown
  - Accelerated Thermal Aging Test Series
  - Acoustic Decay Test Series
  - Power Factor vs Temperature Test Series
  - Corona Pulse Height Measurements
  - Insulation Adhesion Test
  - Thermal Cycle



We offer a complete program of coil/bar tests for rotating machinery including voltage endurance, dissection, dielectric breakdown in oil, accelerated thermal aging oven test series, acoustic decay test series, power factor versus temperature test series, corona pulse height measurements, insulation adhesion test and thermal cycle.  If you are developing or improving a high voltage insulation system, send us a sample to test. We can determine what the rating is of your overall system. Or have us evaluate your production quality control.  We will verify that your production methods are producing a quality result.

400- or 250-hour test as per IEEE standard 1043-1996 at voltages up to 50 kV ac, 60 Hz and temperatures up to 155 degrees C as specified by the customer  (up to 40 kV ac, 400 Hz, 60 hours option  available at the same price). The maximum allowable slot length is five meters, or 16 feet, 5 inches. Pretest activities include physical inspection and, if requested, tan delta (power factor), tip-up, and capacitance measurements at no additional cost. Written test reports provided and will include data/log sheets and test results. Coils shall be in a “ready-to-test” condition, including pre-cut guard circuits consisting of 1/8-inch gaps in the conductive slot tape (for tan delta measurements), when received.

Dissection of each coil cell or bar, including evaluation report and photographs.

Coil or bar is submerged in oil and applied voltage is increased until insulation breakdown occurs.

Five samples per insulation system are subjected to long-term elevated temperatures (typically 140, 160, 180, and 200 degrees C for class F systems) with periodic weight measurements to track resin deterioration. Dissection of samples performed at completion. A written report is provided and includes a description of the failure modes, assessment of quality, and composite insulation class rating.

Ground wall bonding evaluation test includes seven acoustic decay measurements and graphs following seven temperature runs at room temperature, 100, 120, 140, 160, 180 and 200 degrees Celsius, followed by dissection. The tap test is performed after the sample has attained each test temperature and then allowed to cool to room temperature. A written report is provided and includes plots of the acoustic spectrum at each temperature and analysis of results.

Glass transition temperature as indicated by power factor shift will be determined by subjecting the sample to increasing temperatures (room, 120, 140, 160, 180 and 200 degrees Celsius) and measuring the power factor at the end of each isotherm without allowing the sample to cool. A written report includes a graph of power factor versus temperature and analysis of results.

Using an Adwel PDA-Premium Partial Discharge Analyzer, partial discharges from each coil will be measured at a voltage specified by the customer. A graph of pulses per second versus pulse magnitude is provided.

The bar is inserted into a special assembly designed to separate the insulation from the conductor when tension is applied. Several assemblies for various bar sizes have been fabricated. If the test bar does not fit those on hand, either the existing assemblies will be modified or new assemblies fabricated. (The customer is responsible for these costs, including labor. New and modified assemblies remain the property of AEP.)

500 cycle thermal test of form wound stator bars and coils according to proposed IEEE guideline P1310. Pre-test and post-test activities may include physical inspection, tangent delta, tip-up, capacitance measurement, insulation resistance measurement and 110 percent of test voltage proof test as requested. All data sheets, log sheets and results documented in a written report issued after testing is complete. Intermediate measurements made at 50, 100, and 250 cycles.