Hi, I am fitting two pmu 16’s to an older carby car. I am using pulse width control on the fans and all is working correctly. What i would like to do is use the same fans at 50% duty when the air conditioning is on as well as the temp based duty control. I would also like to use a high temp input from a gauge to switch the fans to 100% duty. I currently have analogue inputs wired for a temp sensor, A/C compressor request and a low signal from a driver adjustable gauge for high temp setting. I’ve just got myself stuck in the logic of this and would appreciate if someone could point me in the right direction. Thanks.
I think the easiest way to do this would be a table, add an axis for PWM with the AC on.
For the over ride via the gauge, I would use a number channel that would choose between the PWM from the table or the gauge input x100. Might need to stack number channels to make this logic simpler.
If you’re willing to share your project file I can toss in what i’m thinking
Thanks, didn’t think of adding another axis, seems obvious now. I’ll add that strategy today, then share the project. Thanks again.
Got the PWM control working ok. Couldnt figure out the number channels you mentioned. Project files are attached.
XB Falcon PMU16 B (1).pmu (7.5 KB)
XB Falcon PMU16 A (1).pmu (6.9 KB)
Another problem I’ve come across is one of the fans when running at 100% DC, will be sitting at around 15A current, then suddenly go overcurrent (set at 25A with 80A inrush). When it switches back on it runs fine at 15A again for awhile then trips again and again. Im assuming this is a faulty fan. (Maradyne)
Yeah maybe log the channel at a higher frequency then 20hz and see if you can spot a current change where the overcurrent condition is. Post that log here if you want me to look
Couple things to unpack looking at your calibration:
You can send the raw coolant temp number instead of using the voltage from the PMU input via CAN. That is hard mode haha, but you figured out how to do it.
That also goes for any other inputs, calibrations or even logic channels you have in PMU A and want in B or vise versa. I can show you how to do that if you’re interested
I didn’t see the gauge input you spoke of in either PDM, not sure if it’s a CAN or analog so I just added an input channel named “gauge switch” for now. Feel free to replace with whatever the input is.
I see the AC compressor output is always on… let us know if you want help using the high/low switches logic
I actually forgot about the ‘choose’ logic in the number functions. Take a look at the changes I made and I think you’ll understand how it works.
I didn’t duplicate the number channel for each fan, how you’ve done it isn’t necessary unless you want each fan to operate at different speeds in the same conditions
Hi, thanks for that. I think I understand, when I get a chance ill make the changes and see how it goes. The input from the gauge is on the other PMU (a11 a_WATER HIGH PRO CONTROL) so I think I need to be able to read that as a 1 or 0, correct? Not sure how to do this, but it would definitely make things easier. I hadn’t finished setting up the AC in the files I sent, is all working now (except the compressor leaks, DOH). Thanks again for all your help.
Ahh is that what that was reffering to haha
You could do it the same was as you are now and monitor analog input 11 via CAN, created a function (above x V = true) and just change the channel I made.
Or you can make a CAN export from the 2nd PMU with the switch data, Coolant temp and anything else you want logged or monitored and receive it on the main PMU.
Ecumaster actually make this pretty easy as when you’re done creating the export you can save it as a CANx file and import said file on other devices.