PEM / Motor cooling fan filter

[Tesla 940]

I'm bringing in my Roadster for the "annual" service sometime in the near future and was wondering if anything has ever be developed to filter the dirt/dust before being blown up to cool the PEM/Motor? I admit I have not taken things apart to see what is involved but was wondering if a modified (cut to size) house furnace filter could be used. Periodically I drive on dirt roads and all it takes is one trip (less than a mile) and I have dust/dirt all over the top of the PEM.

Thanks,
Don

 

[wiztecy]

I'm bringing in my Roadster for the "annual" service sometime in the near future and was wondering if anything has ever be developed to filter the dirt/dust before being blown up to cool the PEM/Motor? I admit I have not taken things apart to see what is involved but was wondering if a modified (cut to size) house furnace filter could be used. Periodically I drive on dirt roads and all it takes is one trip (less than a mile) and I have dust/dirt all over the top of the PEM.

Thanks,
Don

If its a 1.5 then you really shouldn't be seeing an issues with the PEM getting clogged / overly dirty. If its a 2.x it sounds like the snow dam is the best solution. There have been pics posted of people putting in filters but I'd be too worried about restricting the airflow, and then you'll have to clean those things regularly since they'll get pretty mucky.

PEM, motor gets too hot -- fans failed - Page 33

I haven't seen any issues myself with the AC electric motor cooling fins getting plugged up, don't think an issue there.

 

[smorgasbord]

This thread: http://www.teslamotorsclub.com/showthread.php/4773-PEM-motor-gets-too-hot-fans-failed includes examples of filters people have tried.


However, none of these will keep the top of your PEM cleaner. The fans blow air through ducts that feed into the PEM, not around it. The dust on top of the PEM is just stuff kicked up through various exposed channels.

You have to be careful with filters. If they clog, they reduce cooling. Even if they don't clog, they can restrict airflow. So, they need to have a large surface area, and you'll need to stay on top of keeping them clean.

 

[dhrivnak]

I added the following to my 1.5 to keep dirt away from the bottom blower. Overall I am told my Motor/PEM is much cleaner than the average Roadster. I made them out of the plastic corrugated sign material and painted it black to make it disappear. I did not like how the rear wheels could easily kick dirt into the blower area. Now the rear shroud acts as a large screen filter. It will at least keep leaves and most grass out. I attach it with black Velcro tape so it can be removed with little effort.

 

[JohnGarziglia]

I have a 2.5 with the snow dam but even that does not keep leaves from getting up into the fan cage and lodged in the squirrel fan.

Once leaves are in there, the fan becomes unbalanced and causes significant vibrations when spinning rapidly. Not only is it annoying and noisy, my concern is that an unbalanced fan will cause premature fan bearing failure.

Tesla during the annual service would clean it out but leaves seemed to get back up in the fan fairly quickly after being cleaned out. So, I decided that I would try to fashion something to keep the leaves from getting in the fan while not blocking airflow.

What I did was to wrap the fan and fan motor housing in "Gutter Guard" plastic mesh which I got at my local Home Depot, and fasten it with wire ties. It is flexible enough to wrap around the fan housing, and the openings are large enough that I cannot see the openings getting clogged. I did watch the temperature gauges after installing it and noted no change. It has now been wrapped in Gutter Guard for about 45 days and so far, no vibration meaning no leaves, at least for now.

In taking off the rear under shield, I had trouble removing two of the screws. Even though I thought I had every screw-head adapter made, when I tried removing two of the screws, the insides rounded out and I ended up having to drill out the screw heads. Therefore, I recommend that a dozen new stainless steel button head cap screws be purchased (also available at Home Depot) at the same time as the Gutter Guard is obtained. You likely will not regret having new stainless steel screws to put in, especially if the existing screws are rusted or have been removed and installed more than several times with an air impact wrench.

Here are the screws to get:

For what it is worth, here is the "Gutter Guard I used to wrap the fan cage and fan motor:

Also, while I was in there wrapping the fan cage and motor in Gutter Guard, I noted the make and model number of the fan in the event I ever need to obtain a replacement. It is a 12 volt SPAL Type 014-AP74/LL-22 which appears to be this fan: Centrifugal Blower Detail | SPAL