PEM cleaning now higher temps?

[sethr]

The PEM may not be as cool as it seems, as the temperature reported is the lowest temperature. Power will be limited by the highest sensor temperature, but that's not what you see on the VDS. I had power limited due to high PEM temps a couple of years ago (clogged with leaves, of course!) and this is what the Tesla tech told me. IIRC he also said there are 3 sensors.

 

[Mark77a]

The discrepancy in PEM temperature sensing in the picture I posted was after parked up (for 16 days, not driving). So (all 3) sensors are stabilised - they are actually same as the ambient temperature, and motor but PEM shows +8degC warmer, on OVMS.

I assume this +8 degC discrepancy also applies when driving.

 

[ShawnA]

Hi Rotarypower,

I may be mixed up here, but it looks like you may want a pair of blowers that are closer together...
The port is a fair match on the PEM, but looks like the blower port is past the inlet on the motor.
A narrower setup may have to be mounted off-center toward the PEM, but would seem like it would cover the
motor better...
Or am I looking at this backwards?

Shawn

 

[Roadster]

The hose is lose
put it back is possible do from wheel well

Would love to see a how-to on this: or, at a minimum, a photo of the house and connection in question.

 

[Rotarypower]

Hi Shawn....yeah, I think you are looking at it incorrectly. The PEM fan is mounted to the right of the opening (inboard) and the motor fan inboard to the left. This results in the airflow outlet hitting part of the structure, but also in the PEMs case, the flow hits the part of the duct that has to change the airflow direction by 90 degrees immediately. If that fan lined up more biased toward the left (outboard) then flow would be more directly into the flex hose going up to the PEM. Needless to say this results in a very inefficient system design. Obviously some airflow is getting to both components but not as much as could be.

 

[nicky _cwt]

Hi Rotarypower,

After doing the improvements you mentioned, how does it affect the PEM temp?

 

[Rotarypower]

I now believe I have the infamous connector burnout on my pem. Motor still works but temps still seem high so my guess is that I’m only getting half the current to the motor from one driver circuit board only. This is one of my projects this summer to resolve.