Motor Circuit Analysis

Deenergized Testing & Motor Circuit Analysis (MCA)™

Motor Circuit Analysis (MCA™) is a deenergized test method to assess the health of a motor. Initiated from the Motor Control Center (MCC) or directly at the motor itself, this process evaluates the entire electrical portion of the motor system, including the connections and cables between the test point and motor.

Electric Motor Predictive Maintenance testing device by ALL-TEST Pro.
Induction motor testing tool by ALL-TEST Pro.

Why Traditional Megohmmeter Testing Isn’t Enough

Megohmmeter insulation testing only detects faults to ground. Since only a portion of motor electrical winding failures begin as ground faults, they will go undetected using this method alone. Moreover, surge testing requires the application of high voltages. This can be destructive when testing a motor, making it an unsuitable method for troubleshooting and true predictive maintenance testing.

ALL-TEST Pro devices offer more complete motor testing than any other options on the market. Our instruments go above and beyond normal testing equipment for accurate, safe, and fast motor testing.

Motor testing using MCA™ tools is very easy to implement, and the test takes less than three minutes. Save money and time by proactively detecting developing faults before they cause irreversible motor failures.


Meg-ohm Meter



Ground Faults




Internal Winding Faults




Open Connection




Rotor Faults








Electric motor PdM instrument with Motor Circuit Analysis technology.

Deenergized Testing Applications

Too often, equipment operators won’t seek help until a motor starts to make a grinding noise. Now, you can file maintenance requests proactively when necessary using ALL-TEST Pro products.

Our MCA tools are ideal in the following areas:

  • AC/DC Motors
  • AC/DC Traction Motors
  • Generators/Alternators
  • Machine Tool Motors
  • Servo Motors
  • Control Transformers
  • Transmission & Distribution Transformers (Virtually Any Size)
  • For Commissioning Testing
  • For Troubleshooting
  • For Reliability Testing

How Does it Work?

The electrical portion of the three phase motor system is made up resistive, capacitive and inductive circuits. When applied low-voltage, healthy circuits should respond in a specific way.

ALL-TEST Pro MCA tools apply series’ of low voltage, non-destructive, sinusoidal AC signals through the motor to measure the response of these signals. This deenergized test takes only a few minutes and can even be performed by an entry-level technician.

MCA measures:

  • Resistance
  • Impedance
  • Inductance
  • Fi (phase angle)
  • Dissipation Factor
  • Insulation to Ground
  • I/F (current frequency response)
  • Test Value Static (TVS)
  • Dynamic Stator and Rotor Signatures

    Schedule A Demo

    Want to learn more about which product is right for you? We provide comprehensive virtual and in person demonstrations to ensure our customers purchase what they need to get their job done right.

    Questions? Call Us +1 860 399-4222

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    ALL-TEST Pro is an electric motor reliability company.

    The ALL-TEST Pro Promise

    ALL-TEST Pro is committed to ensuring the reliability of your businesses’ motors to maximize optimal productivity of maintenance teams everywhere. Our equipment is used in commercial, government and military institutions worldwide. Applications include AC/DC electric motors, transmission, distribution transformers, machine tool motors, servo motors, AC/DC traction motors and more.

    About ALL-TEST Pro

    ALL-TEST Pro is a leading manufacturer of electric motor predictive maintenance (PdM) equipment and condition monitoring tools. ALL-TEST Pro electric motor testing devices surpass other instruments by accurately and quickly diagnosing motor health issues to ensure electric motor reliability and reduce unnecessary facility operational and repair costs. All diagnostic instruments are handheld and lightweight making them exceptionally suitable for field testing applications. The current line of motor testing devices use Motor Circuit Analysis (MCA), a proprietary technology developed by ALL-TEST Pro, and electrical signature analysis, to evaluate electrical issues of components within motors. ALL-TEST Pro products are widely used in nearly every industry that uses electric motors, generators or transformers, and are available worldwide.

    Contact Us

    Email: [email protected]
    Tel: +1 860-399-4222
    Fax: 860-399-3180

    Email: [email protected]
    Tel: +1 860-399-4222

    Corporate Headquarters
    ALL-TEST Pro
    20 Research Parkway, Suite G
    Old Saybrook, CT 06475

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