Observed temperatures from x-gauges

MG and Inverter temps observed today only, outside temperature was about 40 degrees F. grill not blocked.

MG1 and MG2 temperature: MG1 warms up faster than MG2 but after about 15 or so miles of freeway driving they both reached about 75 to 80 degrees C.

Inverter 1 and 2 temperatures: After the car warmed up they seem to range all the way from approximatelly 15 up to 30 degrees C. They change temperature rapidly depending on the current through them and completely independent of each other. I was surprised at how fast they change.

ICE coolant temperature usually runs between 192 and 196 degrees F. at 70 MPH. At 55 MPH it seems to stay around 185 or so. The warmest I have seen it was 205 last summer climbing a long steep (8%) grade, using a lot of throttle, when it was 90 degrees F. outside.

I'll check the DC to DC converters in a day or so.

 

I don't have good numbers yet (as all ever do is drive to work which is 2 miles ... not enough to warm up) .... but around town in city driving, MG2 gets warmer than MG1.

You guys can read the temps in F if you want by just changing the MTH. See the spreadsheet to see the new MTH to use.

 

That makes sense doesn't it, MG2 gets a lot more use in the city. I'll change temp to F today, it will be nice to have all the temps on same scale.

 

Today on the way to work MG2 was at 86F when I got to work and MG1 was at 75F. Also coolant temp was about 140F. (And I had the heater totally off today.....)

 

I would love to see these numbers for highway speeds in below-freezing temps - keep them coming. :thumb:

 

It was 48 degrees today, I took a 70 mile freeway trip at indicated 72 MPH, actual 70 MPH. These are in degrees F, I reentered the math so everything would be in the same scale. Both grills are still unblocked.

ICE coolant=between 194 and 197
MG1=176
MG2=159
Inverter 1=70 to 100
Inverter 2=60 to 70

Weather is pretty nice here now, if we have more cold weather I'll try to do a retest. I'm anxious to see what they will be when it's over a 100.

 

An interesting factoid: the Hybrid ECU has metrics for max MG1 and MG2 temp (since ECU reset, I assume) ... I noticed my MG2 had a max temp of 140... forgot what MG1 said.

 

Inverter coolant temperatures, with ambient temperature in the 40s, seems to stay around 60 degrees F. on the highway and a little more in town. Highest I've seen after running on the battery for 3/4 of a mile was 78 degrees. Grill is unblocked.

 

I've seen temps in the low 80's around town in LA ... outside temp was in the mid 60's I think. I do notice the inverter temps and it's coolant temp seems to be relatively close.

Does anyone know if the the inverter coolant runs through any part of the radiator? I don't seem to recall seeing any hoses running to it.... Also, if it actually did share part of the radiator, the inverter coolant would probably heat up from the engine coolant and be a similar temp. Maybe there is a separate mini radiator somewhere.

The relative low temps of the inverter and coolant should keep the inverter happy for a long time.

 

It is located behind upper grill.
http://priuschat.com/forums/gen-iii...62556-2010-prius-grill-blocking-strategy.html

The inverter coolant will be happy when the temperature is as low as possible, from ambient temperature to approx 160F.
The ICE coolant will be happy when the temperature is approx 190F.

Ken@Japan

 

My understanding is that the inverter coolant has a water pump and uses the top part of the radiator in the Gen3, bottom part in the Gen2. Unlike the ICE which needs to get up to operating temperature the inverter cooling system has no thermostat because the "cooler the better" for large solid state devices, at least at temperatures we will experience.

 

Thanks Ken, would you say that we would be OK blocking the upper grill as long as the inverter coolant temperature stays down below 160 degrees F?

Also what would be a good maximum for ICE coolant, I have seen as high as 205 climbing a long very steep hill in the summer, some have said they see 205 with both grills blocked even this time of year.

 

I think it is difficult to say what is the safe max temperature of inverter coolant.
The inverter coolant pump always runs to keep the coolant as low as possible.
I think it is more important to check the temperatures of MG1/MG2 and inverter/converter devices than the coolant.
My personal opinion is that it is good to keep MG1/MG2 temperature below 120C(248F) and inverter/converter devices below 85C(185F).

The thermostat starts to open at 82C(180F) and fully opens at 95C(203F). Therefore, about the ICE coolant...
below 180F:blue zone: cold
180-203F:green zone: good and acceptable
203-208F:yellow zone: semi-overheat
above 208F:red zone: overheat

Ken@Japan

 

Ken, I know MG1 is water cooled, and it looks like the mini-radiator and inverter coolant flows through it? (I was never sure before what "liquid" cooled it.)

I would be wary of obstructing the airflow through the openings of the front bumper just to make sure the inverter coolant gets as much cool air as possible, unless it's possible to do it in a way to ensure flow is not blocked to the mini radiator.

 

The inverter coolant flow is as follows;

• reserver tank
• coolant pump
• MG1
• inverter radiator
• inverter/converter devices + inverter coolant temperature sensor
• reserver tank

Ken@Japan

 

FYI,
We know some ECU's have a function to record unusual events.

I saw following information on the closed Japanese forum.
The overheat events are triggered at the following temperature threshold.

• MG1 > 162C/324F
• MG2 > 168C/334F
• inverter coolant > 65C/149F

Ken@Japan

 

WOW! Those temps are insanely high. (Well, MG1/MG2 temps at least.) I would think by the time MG1 reached 162C, the coolant temp would be a lot higher than 65C. LOL!

 

-

 

Driving up moderately steep hill out of the desert at 65 to 70 mph with outside air temp of 106F and AC auto 76 degrees the ICE coolant went from normal around 185F to 204 to 206F. Inverter coolant was around 165F. I've just installed scangauge II and am still getting baseline info.
2010 II with 1800 miles.