The majority of the life cycle costs of an electrical motor comes from energy consumption. The purchase price represents some 2% of TCO (Total Cost of Ownership) of a motor with a life of some 20-40 years. Electrical motors have parts that wear down (e.g. bearings) in addition to which dirt and mechanical and thermal strain wear down the motors. In-shop service is recommended depending on the type of use (type of load, number of starts, environment) every 10-15 years. Even coiling might have to be done 1-2 times during the life of a motor, this also is done in most cases at the shop. The share of life cycle costs of maintenance represents some 10% and coiling up to 50%of the purchase price.
In addition to the maintenance costs also preventative work must be included in the total costs, this includes e.g. lubrication, condition monitoring, cleaning etc.) The costs of preventative measures can be significant over the life of the motor.
As a whole, the maintenance cost can equal the purchase price when calculated over the life of an asset. This sum can easily grow to tens or even a hundred thousand euros over the life for bigger (> 100kW) motors. Condition based maintenance aims to minimize these costs while maximizin the uptime.
A scheduled maintenance program is easier to budget, but it falls short on cost when compared to condition based maintenance. A failure caused by aging or wear come seldom as a surprise of the asset is monitored regularly. The challenge with periodic monitoring is, however, in keeping the conditions same and te measurement results comparable. The conditions, load, use all vary). With continous monitoring it is possible to not only spot ong term trends but also short term fluctuations, with which is it easier to predict maintenance needs and the impact the maintenance has. Very often the requirements for the motor change over the life of the motor and might differ greatly from the purchase moment of the asset.
One of the big benefits of continuous monitoring is to get to the core of the biggest cost component – energy consumption. For example understanding temperature tells a great deal about load and loss. Vibration monitoring can lead to the contributors to loss such as resonance, imbalance, misalignment, lubrication and friction. Vibration consumes always energy, which is away from the actual purpose of the motor – generating torque. Continuous monitoring also tells how the motor is being used. From the results, one can read how well the motor serves the production process, and it can also give indication to the optimization of the entire process.
Implementing continuous monitoring is technically easy and the cost is reasonable. Ready solutions and components are readily available. Implementing the technology is easy, the question is who can set the correct parameters and interpret the results.
ABB Motors and Generators Service offers condition monitoring services, where the customer can purchase a full service monitoring and analytics service. ABB will deliver and install the system, configure the parameters and if desired take care of the monitoring and interpretation of the results.
The entire solution can be delivered as a service, with one monthly fee. The system can also be installed without interrupting the process.
This type of a monitoring as a service does not require personnel or equipment investments, nor does it require additional training.
I believe that in the future new services will emerge as an alternative to buying a motor. There will be service that take into account better the entire life cycle costs, for example, buying a guaranteed torque with a fixed monthly fee. In a business model like this it is imperative that the service provider has 24/7 information from the motor and its environment and use. As an intermediary step to this kind of a torque-as-a-service business model could be a torque-guarantee from the equipment provider in exchange for a 24/7 access to the same information.