The equipment we carry out six monthly PMs on feature several small dc motors and power supplies. Could carrying out thermal imaging of these components be beneficial and, if so, in way way would it be best to proceed.

The more critical these are to the process, the more beneficial it would be to IR them. The motors can be profiled for a base signature (thermogram) and motor problems can be detected to predict/prevent failures. The power supplies can be done the same way. Possibilities with the power supplies include loose connection or board component problems/failures. Depending on the history and criticality factors I would IR them monthly or atleast before each PM. Do you have trained personnel and a IR program manager? Bill Morgan, CPE, IR Level III Thermographer

We are starting from scratch with IR. The idea is to incorporate it as part of our PM procedures. How important is it to have trained personnell and what role would a program manager perform?

Training is very important. I believe a good Thermograpy program is impossible to have unless you and your personal understand the effets of emmisivity, transmitance, and reflectivenss of the material that surrounds what you want to use your camera on. There are inherant pitfalls some being wind affect, distance, range, and the ability to determine the correct pallet to select for viewing. Just my opinion and I am not and expert but have used it to survey equipment.

Bren,
Here are a couple words of caution regarding thermography:

1. Know what question you are looking to answer with that technology.

- For instance, if you want to know the running condition of the DC motor you might look at it's current draw and measure vibration, you might measure output and ripple voltage on the Power Supplies (if they are DC) to ensure components aren't failing.

The point is Thermography is just another tool in the diagnostic tool box, use it when other technologies can't answer your questions or when it will corroborate some other data you have.

2. What are the criteria for specific components? The bearings? Motor casing temps? Components in the power supplies...some resistors or power transistors can get really hot. How hot is okay?

3. Thermography really is an Expert technology that presents a lot of oppurtunity to get bad or miss leading data but it also presents the oppurtunity to solve difficult problems when applied properly.

I only write because I've been there (as a data collector) lacking direction, taking thermograms with no idea of what failure mechanism we were looking for.

So definatly take some baseline pictures of your DC motors and power supplies keeping in mind my comments.

Best Regards,

Hugh Hackett

As I always say..
The more data you have the clearer the picture!

Ignore the cost for a moment and imagine your condition monitoring equipment as an extension of yourself.
When you walk up to the side of a machine you look at it, listen to it, note any smell present and may touch it with your hand.

The technology we use today is just an extension of these age-old methods. The difference being that instead of being "hot" we can now be accurate to decimal degree precision. Instead of saying that it is running rough we can identify the frequency and magnitude of vibration.

You know the cost associated with the equipment you wish to use and the potential cost savings from improved monitoring of the equipment. If the two justify each other then thermography is definitly something to implement. Whether you do this after training or involve a specialist is down to the time and money budgets available.

All for now,
CE