Should I repair my electric motor or replace it when it fails?


“Should I repair my electric motor, or should I replace it?”.

This is a question that’s asked around the world every day…..and the answer?

Well, the answer you will get depends on who you ask. And, If you’re the one responsible for getting your plant back up and running again, the answer might not be in your best interests either.

Just consider this for a moment. You ask two people that same question. One is your local electric motor rewinder and the other is an electric motor stockist. I’m fairly sure that you’ll get a different opinion. The rewinder might want to keep the guys in the workshop busy so they’ll likely suggest the motor is repaired, the motor stockist probably works on commission, so they’ll want the sale. So, it’s back to you to choose.

So, who’s right? Well I’m in no position to tell you what you should do for your business. I’ll just offer some things to consider and some questions to ask for you to make your own opinion.

It could be said that it’s too late to ask the question whether to repair or replace a motor when the motor has failed. In many facilities this question has been asked proactively in readiness for when the motor needs to be removed from service. It could be as simple as recognising that the motor is an older, less efficient type motor and that a new IE3 or higher, motor would suit better. There are those of us in the industry who can survey your installed plant with you, then offer suggestions based on running costs and motor availability to help you make a decision proactively.

The most usual scenario is a reactive one though, when you have a failure and you are considering your options. This is where I believe productivity should lead your decision. If production output is critical and there’s a new motor available to you quickly, then that’s probably your best option. I’m sure there will be rewind companies reeling in horror at this, our industry’s reputation is built on providing quick turnarounds with us working through the night to get a motor rewound and back into service as quickly as possible. That’s all well and good, and as an industry we’ll continue to do this, however production demands should always come first.

What if I have a spare motor in stores?

But if you have a spare motor available or you can live with downtime. The ‘repair or replace?’ question still needs answering. This is where a conversation with your repairer is valuable. If your motor is an old motor and a replacement is offered because “It’ll be more efficient”. Ask to see the running cost comparisons to make your own decision. Every repair company should be able to offer you this. There are times when the failure mode of a motor causes too much damage to it, then it really is better to replace. We can all perform miracles but sometimes the scrap bin is the best place.

Let’s look at the most common scenario. When a motor needs a rewind, I wouldn’t automatically look to replace it. If it’s already an IE2 or IE3 motor, then a rewind, done properly of course to ISO60034-23 will bring that motor back to a ‘zero hour’ rebuild. It can be as good as new. I would always offer a repair price and a replacement price. A cost-based decision can be made here as to repair or replace. But then we have to watch out for the purchasing department, who with little engineering input, say that if the repair is a certain percentage of new, then they won’t repair. Why is this though? If you’re getting a repair that’s as good as new, with the same guarantee as new, for less money, then why not repair?

When someone suggests to you that either a repair or a replacement motor is better for you, ask them “Why?”. You’ll hopefully get a reasoned technical and cost-based answer, if not you’ll soon figure out who’s interests are best being served.

Electric Motor Repair Page