Mg1 & mg2 temperature???

I don't monitor these temperatures and the JP repair manual does not show them.

But, the JP manual says the warning thresholds are 162ºC on MG1 and 168ºC on MG2.

Ken@Japan

 

It is 162ºC.
The system will trigger a waring above 162ºC.

Ken@Japan

 

Most heavy duty industrial electric motors today have NEMA Class F insulation that is good for 155 degrees C. So, 162C for MG1 and MG2 is within this range.

 

how to monitor those stuffs? I never them on my display panel.

 

Most on here are using an external device called a ScanGauge II. It plugs in to the OBDII port and extracts this kind of data from the different ECU's and displays them.

 

162 degrees Celsius = 323.6 degrees Fahrenheit. Wow that is way to hot! My MG1 was 204f today at 65 MPH after traveling 75 miles. I am going to talk with Toyota to find out what temp MG1 should be.

 

Below are NEMA class ratings.

Temperature Tolerance Class
Maximum Operation
Temperature Allowed
Allowable Temperature Rise at full load
1.0 service factor motor 1)
Allowable Temperature Rise
1.15 service factor motor 1)
Class. C. F.
A 105 221
B 130 266
F 155 311
H 180 356

 

This is from Toshiba,

Application Guideline #4 indicated common causes of motor failures, and it was determined that temperature kills motors. Ideally, a motor should have a relatively high insulation temperature rating, and a relatively low operating temperature for both the insulation system and bearing system. This provides for thermal margin in the event of motor overload, severe starting duty, safety margin for adjustable speed drive applications and for many other reasons indicated in ‘Application Guideline #4’. (A well-accepted rule of thumb is that for every 10°C, that the motor temperature exceeds its rated insulation temperature, the insulation life is reduced by half, likewise for every 10°C cooler, the insulation life is doubled.)

 

Is this true? That is smoking!

 

I used to monitor both of these , as I remember they slowly drift up to the engine coolant temp after a few hours, I never saw anything much over 190F

 

That is what I am finding. Over short trips they don't get too hot. They just slowly creep up. This is in 50F temps and 100% lower grille blocking. Inverter coolant temp eventually creeps up to 90F if using EV a lot.

 

I would have liked to know what my temps were at on my 13 hour trip at 75mph.

 

Ken, thanks for the clue. I was able to find the same values in my bootleg .pdf copy of the US Repair Manual. I searched for MG1 Temp High and there is was on page 3972 (YMMV) under Operation History Data. It's higher than I would have guessed.

That tells me Toyota is using some very high quality insulation and solid state components in the MG units.

Now, if only we knew what life Toyota expected at 162C. I kind of doubt they would set the alarm level as low as 1/16 design life, but lets say they did. That would mean nominal design temperature for normal life was 122C = 252F. An operating temperature of 102C = 216F would give 64 times the insulation life as 162C.

 

I made a few edits to make this more readable:

Everything posted is normal: ICE > MG1 > MG2

MG1 is between the ICE and MG2 so it tends to run at a temperature between the two. If MG1 is greater than the ICE, then the car is being 'stressed' and I would reduce speed. I've only seen this on hot days, climbing large hills, ~150M (~500 ft), at high speed, 120 km/h (75 mph). MG2 is on the end so it has a lot more cooling including an inverter coolant channel.

Inverter temperature changes rapidly depending upon the current load. Certainly 25C is OK but I suspect if you were recording the data you could see large changes depending upon load (i.e., climbing vs descending.) The traction battery 27C is warm but not unreasonable. If you can use "B" when descending steep grades, you'll minimize traction battery temperatures but it really depends upon your driving conditions. Mostly, just drive the car.

The highest ICE temperatures I've ever seen are ~97C right after the car turns on the radiator fans. This reduces the temperature to ~92C when the fans turn off. The coolant from the radiator eventually reduces the ICE temperature to ~88C and then the cycle repeats. But I only saw this when the car was stationary and I was drawing 930W.

You mentioned 'radiator blocking is not safe' and this is something I do with our 2003 Prius but not the 2010. The North American 2010 has a exhaust, heat recovery system, so I'm not worried about the engine getting too cool in cold weather and thus forcing the engine to run.

I did one set of tests with our 2010 and confirmed a full, bumper block reduces high-speed, aerodynamic drag. But without an active vane or valve system, the 2-4% fuel saving doesn't seem a good tradeoff.

Bob Wilson

 

Bob, that looks like a reasonable conservative approach except that Toyota allows MG2 6C higher temp before it sets an alarm. It's still looks like a good idea for unquestionably long MG life.

P.S. 500 feet isn't a large hill.

 

For 162C, the insulation class has to be Class H. Class F only up to 155C.



From the graph, 162C is approx. at 100,000 hrs or about 11.4 yrs. The operating temp. is much lower than 162C so it can last even longer.

Vincent

 

Thanks for adding some data to the discussion. The unknown is that we don't know what insulation life is acceptable to Toyota at 162C. If 10,000 hours at alarm conditions is acceptable, and I suspect it is, then is could be class F. Class B looks like it's good for about 4500 hours at 162C. That would be around 150,000+ miles at reasonable speeds. I wouldn't be surprised if it were only class B. If I had to bet money on it I would bet on Class B because I doubt you could sustain high enough temperatures to kill class B without toasting the WS oil and having gear and bearing failures first.