Just recently my second controller went belly up while riding along the Wasatch Mountain range. This controller with the original factory settings had not been reprogramed or modified in any way. I used only the first two preset PAS levels(out of the nine PAS level setting) PAS1 and PAS 2 (current 52% and 56% respectively) with no throttle in the ride. About one hour and twenty minutes and 18 miles into the ride the controller went out in PAS2. The motor enclosure was noticeably hot.
The controller was sent to Paul at EM3ev and he replaced it free of charge under warranty within a week or so. Here is part of the e-mail I sent him:
A couple quick questions: After having this happen twice, we would like to know how we can avoid it from happening again. There does not seem to be any protective fuse or breaker that would normally be found on an electric motor. With my experience as an electrician I have found that almost every motorized electric devise I have encountered has had some kind of protective circuity. Does the manufacturer plan on integrating something like this into their next model?
And Paul’s response:
The reason the latest unit failed was the settings we had used, it should hopefully be much better with the settings closer to standard. There is no protective device that is going to save the controller I’m afraid, it is not as simple as that. Hopefully the new settings will be safe and this problem does not occur again.
Unfortunately this reply did not boost my confidence in the product for after looking at the settings of the new replacement controller we found that there were no changes – everything was programed as the controller before.
Since the controller's malfunction seemed to be temperature related I installed a temperature sensor so that I could monitor how hot the motor was running while riding:
My first attempt was made by using this simple meat thermometer.
In order to gain a more precise read as to the actual temperature of the controller I epoxied this sensor to the potting in the controller:
View attachment 3
I then installed the control wire and mounted the digital display that can be conveniently referred to during the ride:
This temperature sensor was easy to install with no holes drilled, just by pushing the sensor through the existing rubber grommet where the other three wires exit the motor housing. And the sensor / display is an inexpensive fish tank aquarium thermometer that can be purchased on eBay for a little over $4.00. Here is the link: http://www.ebay.com/itm/LCD-Digital-Fish-Tank-Aquarium-Temperature-Thermometer-Water-Terrarium-BT6U-/121445513132?pt=LH_DefaultDomain_0&hash=item1c46b777ac
The results:
After three rides I have found the average working temperature of the controller to be around 100 degrees F when traveling in PAS on flat terrain. With moderate climbs the temp is around 110F and when riding long sustained climbs I have allowed the temps to reach as high as 120 to 125F. I think that the controller can tolerate temps as high as 140F without blowing the MOSFETs, but thus far I have chosen to error on the side of caution by not exceeding 130F.
Hope this helps...
