Is It Possible to Check if Your Motors are Defect Free?

YES, it’s possible to check if the windings, insulation, rotor, stator, power supply, and connectors are free of defects.


A study conducted in 1985 by the Electric Power Research Institute (EPRI) in association with GE found that motors failed 41% due to bearings failures, but 47% of the time due to rotor and stator failures.

1985 EPRI/GE Study EL 4263-286 Volume 1 Project 17

You Don’t Have to be Part of the Statistics

Motor Circuit Analysis (MCA) test the motor when it is off-line, thus making it Safe and a Convenient method to test you motor’s health. Motor Circuit Analysis (MCA) is a de-engergised test method to access the health of the motors in your plant.

This method can be initiated from the Motor Control Centre (MCC) or directly at the motor, itself. The advantages of testing from the Motor Control Centre (MCC) is that the entire electrical portion of the motor system, including the Connections and Cables between the test point and the motor is evaluated.

How Does It Work

The electrical portion of the 3 phase motor system is made up of the basic motor circuit, which is nothing more than 3 simple RCl circuits (resistive, capacitive, inductive). Each basic circuit represents one phase of the three-phase motor system. Each phase of the motor system is identical, each basic circuit should respond the same way to an applied signal.

Diagnostic with regards to failures can start as indicated in the below image, between turns in the same coil, between coils in the same phase, and phase to phase. Motor Circuit Analysis provides a Complete view of the motor in just minutes.

Typical Test Sequence

Traditional Megohmmeter – IS NOT ENOUGH

Megohmmeter insulation testing will only detect faults to ground. Only a portion of the Motor electrical winding failure begin as ground faults, they will go undetected using this method, alone. Moreover surge testing requires the application of high voltages, which can be destructive when testing a motor, making it unsuitable for troubleshooting and true Predictive Maintenance Testing.

Megohmmeter Vs. Digital Multimeter

Therefore,  when  testing  Three-phase  equipment  such  as  motorsgenerators,  or  transformers,  the  response  of  each  phase  is  compared  to  the  other  two.

Phase  resistance  is  evaluated  to  determine  connection  issues;  Inductance  is  evaluated  for  possible  rotor  problems;  Impedance  and  inductance  matching  are  used  to  detect  contamination  or  over-heating  of  the  windings;  Insulation  to  ground  tests  detect  conductor  to  ground  issues

Motor Circuit Analysis Is the Way Forward


Typical applications where Motor Circuit Analysis is most effective

  • AC/DC Motors
  • AC/DC Traction Motors
  • Generators/Alternators
  • Machine Tool Motors
  • Servo Motors
  • Control Transformers
  • Transmissions & Distributions Transformers

Motor Circuit should also be used for;

  • For Commissioning purposes
  • Troubleshooting
  • And, Reliability Testing

CIS Industrial Services – Expertise You Can Count On!!!

CIS Industrial Services has appointed Dickey Kruger during February, 2020.

Dickey Kruger has 17 years of experience in the field of Motor Circuit Analysis. He has a vast experience in the Mining Sector, diagnosing electrical drives, from a simple Motor driving a conveyor belt to a more complex machines such as, Continuous Miner for the under ground mining operations.

Should you wish to measure your Electrical drives in your plant effectively, please do not hesitate to get in touch with CIS Industrial Services to make use of this wealth of experience, assisting you, making sure your drive’s runs effectively as they were designed too.

About CIS Industrial Services.

CIS Industrial Services are a leader in the supply of advance Oil Condition Monitoring technologies, Vibration Monitoring technologies, Motor Circuit Analysis (MCA), Products, System and Services.

The products we represent are trusted by the world’s leading industrial and commercial companies to monitor Vibration, and Oil, helping to optimise equipment productivity, reduce operating cost, thereby remaining competitive in a global economy.

Should you wish to learn more about our Products and Services, please do not hesitate to contact Lourens Janse Van Rensburg via email: or alternatively via phone: +27 (0) 79 512 8027

Future-Proofing Asset Monitoring at Port…

The infrastructure-heavy operation at seaport, marine and inter-modal terminals, face increasing demand for efficient and cost-effective operation. Advanced equipment and technology underpins port performance, and productivity hinges upon robust asset management.

The majority of port infrastructure (including Container Cranes, Straddle Carriers, Shiploaders and Hoppers) have a useful economic life of up to 50 years, however an increasing portfolio of ageing and expensive assets over time leads to an increase in exposure to business risk. Research suggests that issues resulting from the application of inadequate or incorrect maintenance procedures cause roughly 25% of the total cost of equipment damage and that satisfying short-term operational needs can lead to major asset downtime due to unplanned maintenance and catastrophic failure. 

Increasing global trade is increasing the demand for more infrastructure to combat port congestion problems. Subsequently there has been an increasing industry focus on equipment lifecycle management, and real-time condition monitoring and maintenance strategies as part of a wider approach to the managing of an entire portfolio of assets. 

Oil condition monitoring plays a fundamental role in total asset management. Accurate, high quality oil condition analysis provides a deep insight into the health and status of port equipment. Contamination can quickly lead to oil losing its lubrication properties and equipment damage. Small unseen issues, which if left to develop will cause a major breakdown, are reflected in changes in oil condition, and as oil condition degrades with use, you can pin-point the exact time for maintenance, extending intervals without risk.

Tan Delta sensors were fitted to the primary hydraulic systems of Container Cranes in a busy South African port. An operator panel was installed in each, providing a simple traffic light condition status, whilst live data was streamed back to the maintenance centre. The data enabled the port to extend the intervals between servicing thus reducing direct operating costs, also providing reassurance that in the event of an unexpected issue, an alert would be provided, and action taken in a planned and controlled manner before any equipment damage had occurred. 

“Since the installation we have seen a significant reduction of 32% in our oil consumption. We were replacing our oil prematurely and have since been able to streamline our maintenance across the whole port. With a total project payback of 6 months this technology forms a crucial part of our asset management strategy, and has helped provide complete visibility, tracking and actionable predictive insights across the port”. – Port Operations Manager, South Africa.

Would you like to see how we can save you money?

Contact, Lourens Janse Van Rensburg on +27 (0) 79 512 8027 or alternatively,

CIS Industrial Services (Pty) Ltd – Plant Uptime, Plant Safety, Asset Reliability!