Fan turning on on controller when it's cool outside.

pacman377

Last week I got the XTC 500 from ScottyB. Minus about 3 minutes after installing it taking it for a short test drive I haven't driven it any till today. Today my wife son and myself were out riding maybe a 3-5 minute ride on the road with it wide open but the rest of the ride maybe 40 minutes was ridden 5 mph or less. Just easing around the fields. After a while I heard the fan turn on. The only thing is it was only 53° here in SC today. I'm just wondering if the fan was coming on at that temp with easy riding what is it going to do when its 95°-105° here in the summer and we are riding it faster to keep a little breeze on us. Obviously it's going to run a lot more to all the time. But is something going to get to hot?

BGW

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Zincode

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JohnnieB

There are a couple things other than bus-bar temperature that will turn the fan on. I don't remember the exact criteria, but they are preemptive actions for operating conditions that might eventually overheat the controller. In other words, there are some situations that the controller will trigger the fan before the bus bar gets hot enough to trigger it.

The bus bar (M- terminal) acts as a heatsink for the MOSFETs that pass amps to the motor and the more amps passing through the MOSFETs, the more heat is generated. The bus bar temperature is the sum of ambient temperature plus the temperature rise caused by amp flow, so the heat triggered fan turn on is quicker in warmer weather, but the over-temperature cutback for an XCT is 85°C (185°F) and the over-temperature cutoff is 95°C (203°F), so it take a lot of amps over a long period of time to climb that high. I don't know how hot the bus bar has to get before fan is switched on, but it is considerably lower than the cutback point.

I read your previous post to find out what type cart and tire height you have.
TXT-48 with 23" tall tires and a rear seat, so it is heavily loaded and there is a 22% torque loss due to tire height as well as the motor spinning 22% slower at any given cart speed and the slower the motor spins, the more amps it is capable of drawing. Driving at 5MPH or less for 40 minutes will most likely turn on the fan even if the air temperature was 0°F.

Also, driving slow heats up the motor and so does running wide open. (Motor efficiency goes down to 50% or so at low RPM and at high RPM, depending on the amount of field weakening at high RPM)

Connect a laptop (or similar device) to the XCT and you can view the controller temperature while driving, as well as record a data log for later review. (See attached screen capture - that is very old software, so your screen might look a bit different)

Attached Images

Monitor Tab - Top.jpg (176.2 KB, 0 views)

JohnnieB

FWIW: If you click on the Thread Tools button on the bar just above the posts, you can select to subscribe to the thread without having to post to it.

Zincode

Thank you. I found it...

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pacman377

Thank you for all the information. In the next day or two when we go for a ride I'll hook the computer up and pull the logs and see what all shows.

JohnnieB

Use the Continuous sample rate for the data log. That give you 3 or 4 samples (lines) per second and each line has 40 columns of data, excluding the time and date columns. 29 of the 40 columns are true/false (1 or 0) and the other 11 have numerical values.

The average is about 14K lines per hour and the resulting .csv (Comma Separated Values) file about 1.7 MB per hour, so you can attach up to about a 5.5 hour data log (9.54MB limit of .zip attachments).

If you want us to take a look at it, you cannot attach a .csv file to a BGW post, so Zip it and attach the .zip file.

pacman377

I pulled a log today but it's a .txt file that's just jibberish and characters and symbols, there is no .csv file. Its supposed to rain the next several days so it will be a bit before I can try again. But the next time I'll try again then upload the file.

pacman377

On a separate note I was able to get a good gps reading today. Looks like 25 mph is what it's running right now about 4700-4800rpm on the motor.

JohnnieB

Should be a .csv file. The .txt file full of gibberish sounds like a field map file.

When you hit browse to tell the laptop where to save the file and what to name it, be sure that it has a .csv suffix.

You have to start and stop the data logging. Start it after the laptop sees the controller and stop it before the toolkit program is turned off or the laptop disconnected.