What VFD properties matter the most to you?

Medium voltage VFD is often a long term investment. The expected lifetime is typically at least 20 years. Thus, it is important to make the right choice when purchasing it. That is easily said, right? But there are several products on the market and they all claim to be the best one. So which one shall I choose? Before making any decision maybe you should ask yourself the question: What VFD properties matter the most to me?

The expectations on the VFD may be affected by several factors, for example:

Industrial segment
Criticality of the service
Ambient conditions
Installation restrictions
Local regulations
Country or region
Marketing of manufacturers
Your personal background
Previous experience

Industrial segment

The type of industry plays a major role when ranking the VFD properties that matter the most. In some cases, such as oil and gas, reliability and availability is on of the top requirements. Any downtime is so costly that it shall be avoided as good as possible. Therefore, robust design, proven solutions, design margins and high degree of redundancy are usually the goodies. Local service capabilities also matter as they can reduce the time to repair. Power generation puts additional focus on efficiency. No wonder, as each kW of saved power can be sold to the consumer.

Ambient conditions

VFDs are nowadays installed all over the globe. It means that we can find them also in areas with a bit extreme conditions, such as very low temperatures, very high temperatures, high humidity, corrosive environment or high altitude. Special conditions may requires special design approaches.

Installation restrictions

Many times the drive system shall be installed in an existing building, yard, machine room etc. Thus, the available space may be restricted. In some cases, such as offshore, the space (and weight) is extremely valuable and expensive. There is a huge motivation to keep the VFD as compact as possible while not compromising other important characteristics.

Local regulations

How do local regulations affect the desirable VFD properties? Well, those regulations may define certain minimum efficiency, the noise emissions and of course the harmonic distortion limits. Moreover, they are often non-negotiable.

Country or region

The country of location affects the VFD most wanted properties in various aspects. As already mentioned, some countries (e.g. United States) or regions (e.g. European Union) put specific regulations into effect. Energy price level in the country also determines how much focus is put on efficiency. Country is linked with the ambient conditions. Or the practice in the country/region may result in different expectations when it comes to lifetime.

Marketing of VFD manufacturers

Of course, VFD manufacturers compete heavily. Many of them need to differentiate from the competition by marketing specific VFD features. Some of them are also pretty good in influencing the specifications and even the consulting companies. It may be hard to recognize what are the important VFD properties that matter and what is a pure marketing.

Your personal background and your task

It does not surprise to hear that your personal background and your positon (field of responsibility) shape your focus when it comes to VFD properties that matter to you. As a safety specialist you will likely challenge the safety concept of the VFD. If you have a background in power electronics you may naturally be interested in the semiconductor technology that the VFD utilizes. As a mechanical engineer you may have a deep dive into the frame, cabinet structure, busbar arrangement etc.

Previous experience

Finally, there is the power is previous experience. For example, if you faced unplanned shutdown(s) due to VFD failure then you will most likely keep an eye on availability. If you experienced bad service support you will make sure that it does not happen again. Your experience is very valuable. Our recommendation: Just make sure that the requirements are balanced and you don’t loose other important aspects from your sight.

VFD functionality can be compared to the famous Swiss army knives. There are models with basic functions but also models with lot of “extras”.

Wish list of VFD properties that matter

After explaining the different view points and factors it can be interesting to look at some of the top ranked VFD properties that matter for the users:

Safety
Availability
Efficiency
Service network
Compatibility
Performance
User friendliness
…
…

Of course, the leading VFD manufacturers continuously improve their poducts and try to tick most of the boxes on your wish list. Nonetheless, some compromise may be necessary.

And now over to you: What VFD properties matter the most to you?

Leave us a comment.