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How are you all monitoring temperature of the MG's and Inverter?

Discussion in 'Gen 2 Prius Technical Discussion' started by josh2008, Oct 28, 2008.

  1. 2009Prius

    2009Prius A Wimpy DIYer

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    Just took a photo of my driver side door and saw 3 gaps I could route the cable:

    [​IMG]

    Which one did you use? Thanks! :)
     
  2. northwichita

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    A ; closest to top.

    Though I would guess, that behind, its the same gap. I really didn't do much but use a wire to find it open between the engine compartment and inside of door jam (04 Prius). Since I mounted mine on top of the dash, in front of the little triangle glass area on drivers side, the top was the closest to run the probe wire. Sorry for not getting around to showing in pics.
     
  3. 2009Prius

    2009Prius A Wimpy DIYer

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    Thanks this helps a lot! :)
     
  4. 2009Prius

    2009Prius A Wimpy DIYer

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    Finally got around to install the thermometer for the inverter case. The oven thermometer I bought has stainless steel probe and cable:
    [​IMG]

    I wrapped most of it with tape dope and used silicone to fix the tip to the inverter case and twist ties to fix the handle to the thick inverter cable:
    [​IMG]

    Another view: (What is this black/orange sensor with a yellow connector? It just hangs in mid air without any obvious contact other than the mounting posts. :confused:)
    [​IMG]

    The cable goes this way:
    [​IMG]

    and comes out this way:
    [​IMG]

    I couldn't pull the right angle connector though so I ended up cutting the cable and soldering it back.

    Today the measured temperature started out at 63 F and gradually rose up to 93 F about half an hour later when I arrived at the office parking lot.

    Thanks to northwichita again for providing helpful tips. :)
     
  5. 2009Prius

    2009Prius A Wimpy DIYer

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    Some interesting observations on the inverter case temperature (I will just call it "T" below).

    It seems to take forever for T to come back down after power off the car. Yesterday the car was in the shade most of the morning and all afternoon. At the end of the day when I left office the MFD shows 75F and T=81F. (Yesterday morning the difference between the two was only 1F.) This morning the MFD shows 66F and T=70F.

    Yesterday evening the traffic on the highway was crawling about half of the time. T went from 81F to 77F at cruising speed, then went up to 87F when crawling, came back down to 77F when traffic started moving again, and finally reached 85F when back at home. I suppose this suggests that T is sensitive to air flow and seems easily cooled by it. Also this is consistent with the fact that when crawling a lot of electricity is used to move the car.

    This morning however T only rose a few degrees F for the first 10 - 15 minutes on local roads. Then it rose up much faster on the highway. There was definitely less electricity used on the highway. I suppose maybe the ICE and inverter coolant loops are thermally connected at the radiator and when the ICE heats up it brings T up with it.
     
  6. Doc Willie

    Doc Willie Shuttlecraft Commander

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    How hot is too hot?

    What are the temps that we should be keeping below?
     
  7. 2009Prius

    2009Prius A Wimpy DIYer

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    There are some guesstimates here:
    http://priuschat.com/forums/gen-ii-...imum-acceptable-inverter-temp.html#post681930

    Unfortunately I don't have CanView so I can not measure the inverter temperature, only the case temperature, and I have no idea how to translate between the two. :( My plan is to keep a record of the case T and if it starts to deviate from the norm down the road then I may be able to catch it. ;)
     
  8. paprius4030

    paprius4030 My first Prius

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    Instead of measuring temp. Is there some easy way to know if the inverter pump goes out? Does the red triangle come on as soon as the inverter pump konks out or does it wait for the temp. to go up?
     
  9. 2009Prius

    2009Prius A Wimpy DIYer

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    Just blocked the lower grill today :)

    [​IMG]

    Usually the MFD outside T drops a bit since the garage is warmer than outside these days. Today it also drops about the same amount but much later. So the block seems working.

    Another indication is that usually in the morning the inverter case T also drops some before rising. This morning it did not drop at all.

    Yet another is that the final inverter case T when I left the car was 93F, about 10F higher than the past few days. Of course this is what I need to watch out for - can't let it go too high.

    Finally the ScanGauge gave 65.8 MPG this morning compared to low 60s the past two mornings with similar outside T. It was even raining a bit today which usually lowers MPG.
     
  10. 2009Prius

    2009Prius A Wimpy DIYer

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    Continued T measurements. Inverter case T continued to end up about 10F higher at end of trip. Same change in reduced cooling as described yesterday held this morning.

    The max engine coolant T shot up to 197F this morning. This is the highest I have ever seen since June when I first started using ScanGauge. Usually it is 191F, occasionally 190 or 193F. (Strange I have never seen 192F.)

    MPG did not improve on the trip home and improved less this morning than yesterday morning. Maybe the wind changed or slight air T change. Not sure.
     
  11. cwerdna

    cwerdna Senior Member

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    Have there been any positive developments on monitor inverter temps with SG? I, as many others would like to monitor that along w/MG1 and MG2 temps.

    My commutes are short (~2 miles going to work and <5 miles coming back) but the OATs have are higher now than when I started grille blocking. The lows are now in the low ~40 F range and the highs in the day are in the low 50 F range. I've taken longer trips in similar temps but would really like to monitor the above since I'm blocking all of the upper grille and most of the bottom one.

    (When I started blocking, we were hitting nighttime lows of 18 F and highs of barely above 32 F.)

    FWT hasn't been a concern at all though.