How Many Types of Electrical Maintenance Are There?

I work as an electrical maintenance engineer for a very big oil and gas company. In our work we almost have all types of electrical maintenance. In this article Let’s answer the important question “How many types of electrical maintenance?”.

A short answer is, there are 6 electrical maintenance types. As follows:

  1. Preventive maintenance
  2. Predictive maintenance
  3. Corrective maintenance
  4. Condition-based maintenance
  5. Predetermined maintenance
  6. Reactive maintenance

Now, Let’s go in details.


Electrical maintenance can best be described as the continuous process in which an electrical system is tested, monitored, fixed and worn out parts are replaced.

Electrical maintenance covers aspects of electrical system inspection, replacing worn out parts in order to keep the system running smoothly.

Electrical maintenance is to be performed by a qualified electrical engineer with full knowledge of local regulations and electric code which differs according to regions. Electrical maintenance covers diverse areas such as;

Due to the advent of technological advancements, there are now stronger electrical machines and equipment that can go for long period of time without showing signs of problems.

Nevertheless, a single fault in any element of an electrical system can lead to a total system shutdown which is why electrical maintenance is very important.


Generally, as I mentioned above, there are six types of electrical maintenance namely;

  • Preventive maintenance
  • Predictive maintenance
  • Corrective maintenance
  • Condition-based maintenance
  • Predetermined maintenance
  • Reactive maintenance

For more information about preventive maintenance read my detailed article here. Also you can read my other article about preventive vs predictive maintenance here.


Preventive maintenance has to do with noticing and fixing issues before they happen. During inspections of electrical equipment and systems, certain issues and faults might be discovered which might lead to problems later, preventive maintenance fixes this type of issues saving the business or individual money and expenses that could have been spent in the future.

During inspections, you should check for signs of wear and tear, areas that need more lubrication, or even damaging parts. Then, take necessary action by replacing the worn out or damaging parts which could affect the whole system later if not replaced or repaired.

Also, apply lubricants to areas that need lubrication in order to avoid parts getting stuck.

Preventive maintenance can definitely save you a lot of stress and money you could have used for future repairs.

 Also try to avoid straying into over maintenance, i.e., doing more than necessary, you could be replacing parts that do not actually need replacements at that moment, thereby incurring unnecessary costs.


This is very similar to condition based maintenance (will discuss below) except that here the date is analyzed to infer accurate predictions about future problems.

For instance, with condition based maintenance, you have a system that usually run at X temperature. Once you notice the temperature has increased to Y, you know then that it needs maintenance. The sensor provides you with a continuous flow of data but the software only cares if it’s still within the present ranges.

But with predictive, the system will never get to Y because the software now monitors the data more closely ensuring that it stays within the required temperature range and once it notices a change in the data, it triggers maintenance.


This type of maintenance is carried out when an issue is discovered while working on another problem. During scheduled maintenance and inspection, a technician working on fixing a problem might notice an abnormally in another part of the system. Corrective maintenance is then scheduled for another time where the issue would be addressed.

Corrective maintenance reduces emergency repairs and increases employee safety because issues are found just in time.


Condition based maintenance is based on the condition of the system or equipment. So rather than having a plan to check on the equipment, you are looking for any change in performance that might lead to problems.

For instance, let’s say you have an engine that you want to maintain. You can have a plan where you check the temperature every four hours or you can attach a sensor that will read the temperature, setting alarms when it falls below or above the ranges you want.

This can also be used to detect smoke, so as soon as it does, it alerts you ensuring it doesn’t lead to a large fire outbreak.

There are other things you can also monitor with a sensor; they include;

•           Speed

•           Power

•           Moisture

•           vibration

Since condition based maintenance is done while the system is still running, it saves you time in general. You don’t have to put it off to inspect it, it can be up and the sensors will do the monitoring.

With this type of maintenance, you would be able to cut more expenses because you don’t have to monitor or inspect the equipment as frequent as before and you would only need to do things when necessary.

Being able to effectively monitor your electrical system without having to shut it down saves you more than just time and money. For some equipment, it also saves you the risk of damage and injury to technicians.

For example, let’s say you have a sensor on the fan in your welding stations, means that you no longer have to send a technician to inspect it since there is a sensor there already and it will alert you if there is a problem.


Predetermined maintenance simply means following the manufacturers recommendations for inspection and maintenance. Most electrical tools and equipment comes with handy manuals that explains how they should be maintained and when the service of a qualified electrician would be required.

Most times the manufacturers already set averages and period when the machine should be inspected and due for maintenance, so all you have to do is to follow the recommendations. They have a better understanding of the product since its theirs and must have therefore done extensive research into how it should be maintained, i.e., the main job is done already.

However, sometimes it might not be exactly accurate based on different factors such as the environment in which the product is being used and how much it is used.

For instance, the manufacturer of a generator set might recommend that the oil be changed once every 20 hours of use but this will not be exactly accurate if a substandard oil is used which might cause problems for the generator.


This is also known as run to failure maintenance, it is basically not doing anything till problems occur. This type of maintenance is very difficult from differentiating with having no plan at all whereas it is a plan on its own.

The idea behind this is choosing the right tools for this plan. You need things that are not expensive to carry in inventory, not difficult to change, difficult to monitor and have low issues.

Light bulbs are a perfect example of this, they do not require any special environment to function and they are small in size making them easy to move in inventory. Even when they expend their lifespan, replacing them with new ones isn’t difficult at all.

Planning on replacing them before they go off finally, it is quite difficult to know how much time they have left. Also even if they go off during production operations, it doesn’t stop the operation from running because they can easily be replaced.

This maintenance strategy should be used when you have duplicates of the same tool, giving you time for them to completely run out before replacing. It is also very useful for continuous production facilities that make use of tools that take a long period of time before breaking down, so instead of shutting down at intervals for proactive maintenance which means more expenses, you can keep working until they break down.

An important aim of maintenance is to ensure you get the most value out of your assets and equipment. You should get the highest on your investment, so in order to do that you need to get out every drop of value. For an electrical tool like light bulbs, one can only get the maximum value from them by using them till they burn out.

However, this type of maintenance strategy can save money and also give you the most value since most times all you need is just a small team of technicians to monitor the electrical systems. While other maintenance strategies might involve special skills and knowledge, here even a lay man can understand reactive maintenance