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Vitals: What do those temperature bars mean?

Discussion in 'Roadster: Technical' started by S-2000 Roadster, Aug 7, 2011.

  1. S-2000 Roadster

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    My apologies. I know that this has been discussed (Scott?), but I can't find the topic anywhere. I've searched by title, author, and scrolled through pages of threads. Well, here goes:

    What are the real-world temperature ranges that correspond to the bars (blue/yellow/red) on the Vitals screen?

    My battery never drops to the lowest blue bar, but I assume that exists to indicate freezing temperatures since the battery would automatically be heated in that event. My Motor and PEM always start out at the lowest blue bar, but the PEM quickly heats up to maybe the third blue bar. The Motor rarely even gets as hot as the PEM.

    I've never seen a yellow bar, although I have seen Performance turn red.

    Anyway, I'd like to correlate my Mac log graphing app displays with what I see on my Vitals screen. Any help or links would be appreciated. Maybe this topic can serve as a focal point for temperature discussions if the existing discussions are in the midst of broader topics.
     
  2. TEG

    TEG TMC Moderator

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    #2 TEG, Aug 7, 2011
    Last edited: Aug 7, 2011
  3. scott451

    scott451 KWH-PWR#1349Sprt,S Sig#96

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    Specifically. From white vs. red...

    attachment.php?attachmentid=986&d=1282721159.png
     
  4. S-2000 Roadster

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    #4 S-2000 Roadster, Aug 7, 2011
    Last edited: Aug 7, 2011
    Thanks, Scott.

    I assume that the second 3.4.15 should actually be 3.4.16

    Considering that we're now on firmware 4.6.3, is it possible that the temperature bar thresholds have changed yet again?

    P.S. I also assume that the actual thresholds are in Celsius, not Fahrenheit. Are the temperature sensors all reporting Kelvin? ... or do some of the temperature sensors report values in different units than others? I've done some research into temperature sensor chips, and I've learned that there are varying units as well as wildly varying accuracies.
     
  5. scott451

    scott451 KWH-PWR#1349Sprt,S Sig#96

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    no it's labeled correctly as 3.4.15. The first chart shows the range the second just the lowest temp that the bar comes on.

    This was for my R1.5. I'm currently on 3.5.18 so it probably hasn't changed. I looked at 2.x and saw it was the same, but I don't remember the version. The 2.x can print the temp next to the bar in debug text mode, the 1.5 cannot so it has to be done manually.
    On the CAN bus it's all in Celsius.
     
  6. S-2000 Roadster

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    Good work, Scott. Thanks.
     
  7. rabar10

    rabar10 FFE until Model 3

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    Neat to see those numbers, thanks. Shows how the 'happy' range doesn't really line up between any of the 3 systems.

    I wonder how the liquid-cooling system in the Model S will take this into account, or specifically, how much they will have to separately 'plumb' the cooling systems between the 3 components? Also shows how you'd have to account for thermal issues when bolting the PEM directly to the motor in the new drivetrain configuration (temperature soak from motor to PEM) Neither of these are show-stoppers obviously, just interesting engineering challenges...
     
  8. Doug_G

    Doug_G Lead Moderator

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    Probably the simplest thing would be to have one loop, with the coolest things at the beginning of the loop and hottest things at the end. Even if that means something has to run cooler than absolutely needed, it won't hurt anything and may actually improve durability. Worst-case it might result in having to pump more heat out of the system than would otherwise be necessary.
     
  9. doug

    doug Administrator / Head Moderator

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    From back at the Model S unveiling, JB told me the motor and PEM would share the same cooling loop. I've always understood this to mean the battery pack cooling would remain separate.
     
  10. Doug_G

    Doug_G Lead Moderator

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    That sounds like a very sensible compromise. You want the battery pack to be as cool as possible, so you don't want to load its cooling loop with other heat sources.

    For electronics, as long as you keep them about 30C below their rated temperature limit there's no significant impact on lifetime. Typical maximum junction temperature (meaning the silicon itself) is +125C for automotive devices, so 95C is usually the maximum operating temperature you want to see. The motor could of course run much hotter without damage.
     
  11. hjr

    hjr #1291

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    My Roadster was recently in the shop for a replacement of the Alpine unit's Bluetooth module. After I got the car back the temperature display showed the temperature in numbers:
    tesla temp.png

    I asked at Tesla and they do not know how this got there! At the next service the PEM was cleaned and the temperature screen reverted to the bars only. How can I can the temperature readout back? Any ideas other than look at my OVMS????
     
  12. markwj

    markwj Moderator, Asia Pacific

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    They had put your VDS in 'diagnostic messages' mode.

    Presumably they turned off that mode at your subsequent service.

    Side-effect of turning on that mode is that you also get bothered with not-important VMS error codes (and some of the important ones are less meaningful). I would suggest you leave it off and use OVMS if you want the real temperatures.

    Regards, Mark.
     
  13. wiztecy

    wiztecy Active Member

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    This is turned on debugging while they were in the Diagnostics screen (Its in the VDS and temps are shown with the 2.x's, not 1.5's when in this mode). Its actually called "User Debug". It won't hurt but it will be verbose on errors, some that really don't mean anything bad but just for logging that help's the tech's out. With that you get the real temperature reading in C degrees as you've posted above. It doesn't hurt anything, actually really useful. But when its in this mode you don't want to wig out that for every alert you get thinking your Roadster is about to die from all these messages popping up that you have to dismiss. However when a real issue does occur, you get about 3 or 4 messages. It will say "Debug" in the message by the way. These messages, when used properly, do help the Technician in better diagnosing the issue. If you take it back to Tesla they'll turn off "User Debug" for you within a matter of minutes.
     
  14. hjr

    hjr #1291

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    This is exactly what happened. Incidentally my PEM was super clogged up form New England leaves and spring buds. The alert that came up for the high PEM temperatures was something I had not seen before and in fact neither the service center nor the tech at Tesla headquarters knew what the error message was - that is probably why.

    I don't think they turned off the User Debug mode on purpose after the PEM cleaning - I think it cleared on its own after they re-attached the battery.

    I find the techs and service guys do not know Roadster anymore like they used to - all new service guys. In our area there are hundreds of Model S but only 2 Roadsters I know if so they do not see us much.

    Thanks for the note.
     
  15. wiztecy

    wiztecy Active Member

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    #15 wiztecy, Jun 12, 2014
    Last edited: Jun 12, 2014
    You may want to ask about the winter/snow dam upgrade. I've heard that will help with the 2.x PEMS from getting filled with junk like leaves and crud much better. They may have turned on user debug in order to verify on their test drive that they correctly solved the problem you reported of the PEM overheating by just a simple cleaning. Makes sense to me and the proper way to diagnose and attack the problem.
     
  16. hjr

    hjr #1291

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    They turned it on when they replaced my Bluetooth module. They turned it off (or it reset when power was disconnected) when they cleaned the PEM a month later.

    I have the winter/snow dam upgrade but it still got clogged. I need to clean the PEM twice a year - late fall and late spring.
     

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