Roadster PEM failure

[ion_1]

The mini discussion above is an interesting nuance about interpreting the temp data. An extreme case would be an IGBT with a horrible thermal conductor between it an the sink. You could be blasting the car at 30+C, your IGBT would be glowing hot, yet as the thermal transport to the sink is so lousy, the temp sensor on the sink says all is great(basically it will not heat until radiative transport or convection gets the heat to the heat sink as there is no conduction).

So what is ideal behavior? I assume it would be the rate of response of temperature change relative to the heat being generated by the IGBT (i.e. driving conditions), you don't want the IGBT to be creating a huge temperature gradient before heat is transferred across the thermal conductor (if the termal conductor was poor), you want it to go out quickly.
The important thing for us to realize as Daniel reports on his fantastic mod to the PEM is that success (besides long term stability which is the ultimate goal) is not lower temperatures, it is how fast the temperature rise, and even if he reads higher temperatures, that is good news (as MLauto pointed out). Daniel is focused on getting heat to the sink, getting heat out of the sink more efficiently is another project as other have discussed at length.

In an ideal world we would have an embedded IR camera quantifying the the IGBT, thermal conductor and heat sink in action and compare images of before mod to after mod while driving under the same conditions, but until then we can enjoy Daniel's journey and posts

 

[Jonathanm]

Well I have finally had the chance to get replace the fuse in my PEM and reinstall it in the Roadster. Well the good news is in over 3 months of the car sitting idle (with the service disconnect removed) the car had only lost 5 km's. It is still around 200K's - so no problem with the SOC of the battery.
The news that is less good is that after I had changed out the Megapole fuse I have now a new fault showing "BSM Contacter Power failure." I saw in the list that it is number 271. I found that it was recommended to take out again the service disconnect wait some minutes and replace. This was all done but sadly the error persists.
The other good news is that I am not getting any "Phase saturation errors" that I was getting before. But the BSM Contacter error persists with no possibility of charging or driving.

BTW I have noticed elsewhere where this could indicate moisture in the car - well in this case the car has been the garage for 3 months without anything that even looks like rain...
I also saw somewhere that apparently there is a little "switch" next to the service disconnect "fuse". Well the little plastic lever that locks down securing the "fuse" in position broke on mine when I removed it. I modified mine with an electrical cable tie to make useable...I wonder if this could have anything to do with the error?

Any suggestions from anybody?

 

[PV-EV]

Well I have finally had the chance to get replace the fuse in my PEM and reinstall it in the Roadster. Well the good news is in over 3 months of the car sitting idle (with the service disconnect removed) the car had only lost 5 km's. It is still around 200K's - so no problem with the SOC of the battery.
The news that is less good is that after I had changed out the Megapole fuse I have now a new fault showing "BSM Contacter Power failure." I saw in the list that it is number 271. I found that it was recommended to take out again the service disconnect wait some minutes and replace. This was all done but sadly the error persists.
The other good news is that I am not getting any "Phase saturation errors" that I was getting before. But the BSM Contacter error persists with no possibility of charging or driving.

BTW I have noticed elsewhere where this could indicate moisture in the car - well in this case the car has been the garage for 3 months without anything that even looks like rain...
I also saw somewhere that apparently there is a little "switch" next to the service disconnect "fuse". Well the little plastic lever that locks down securing the "fuse" in position broke on mine when I removed it. I modified mine with an electrical cable tie to make useable...I wonder if this could have anything to do with the error?

Any suggestions from anybody?

From my list of possible faults for #271:

#1 reset inertia switch, see if fault clears. If not, short pins on inertia switch connector and see if fault clears. If so, replace inertia switch. If not, check wiring. You can check continuity across the inertia switch.

#2 Check that service disconnect is installed completely (handle down). If fault does not clear, try new service disconnect plug. If fault continues, check continuity across microswitch.

Being as your disconnect handle is broken I would start there. The micro switch is under the cover on top of the PEM where cables go in and the cover must be installed for the switch to be closed and the contactor to to work.

 

[Jonathanm]

Thanks for the reply - yeah - I'll try and get hold of a new "plug". I tried here in France but they did not seem to have any idea what I was talking about...I'll try someone else in parts...

 

[Rolf68]

after more than 1.000 km on the overworked PEM:
Temp of PEM will raise immediately when you push the "More-Eletrons-Please-Pedal" to the ground in a normal range up to approx. 47 C. 0 1 driving and above 30 C environment it went up to even 50 (still not in the first yellow bar) and it will fall fast too... so my assumption is that the heat transfer from the transistor over the alloy oxide plates to the cooling plates is way better than before... until now... Car runs like a charm (so happy!)

Hello Daniel.

I'm glad your repair was successful.

Now that you had time to test everything extensively, do you think it would be a good thing for owners to have the work done preventively ? Would it cause the 3.0 battery pack not being installed if Tesla sees that the PEM was modified?
And did you change other things, like fans, fuses ?

Can we know how much expense was the repair (if not too sensitive info to disclose)?

Did you give you PEM to a society doing electronics, or is it someone you know that is skilled in the domain? Now that the amount of work is known, how long do you think it would take if someone brings a driveable roadster to this society / person and then had the job done?

Thanks again for all the valuable info you posted here

Best regards

 

[DanielFriederich]

Hi Rolf

The work inside the PEM can be done by a person which is able to handly dissasembling and reassembling a lot of parts like screws, rails, plugs....
Soldering if neccessary needs a bit more since a normal soldering is to weak. Also measuring the transistors needs some basic electronics knowledge
one igbt transistor is around 6,50 Euro...
new insulation between igbts and cooling plates depends on what you choose to use: insulation tape stripes a quite cheap, the alloy oxide plates are more expensive (round 300 Euro) but do a better job
Most of the money will go into the dissasembling and reassembling of the PEM (also depending if the transistors have to be measured...)

All in all costs for me
PEM dissasemble/reasseble incl. measuring transistors approx. 1100,-- Euro (done by a electronic technician...)
alloy oxide plates (insulation) less than 260,-- Euro (I had a chance to get them from China from a guy travelling there... to hard to do again. My suggestion would be to ask Dirk Hansen - Handwind in Germany or Pete Gruber in Phoenix, AZ
spare parts like loctite and thermal grease (not to be used between alloy oxide plates and cooling plates but very thin on the igbts to avoid so called hot spots) 150,-- Euro approx.

I didnt exchange any transistors (still ok even with disruptive discharges!) but bought a bunch of 100 pieces for 560,-- Euro or so....

Ah almost forgot: one day driving the Roadster on a trailer to SEC Frankfurt to get being told that I accidently mixed up Battery Minus and Ground Battery Minus and driving there again to pick it up.... so: 2 days wasted but 10 grand saved

 

[Rolf68]

Hello Daniel

Thanks 1000x for the response

It's great to know all those détails. When you speack about mixing the minus and the ground what really happened? Did it happen when you rewired the PEM to the battery using the three big orange cables at the right side of the PEM, or was it something more subtle?

Now that you battled through this PEM Hell, do you thing it would be a good move to change the insulation before any failure happens ?

And last question, you seem to live in Neustadt, south of Frankfurt. Does your electronic technician live nearby? It could be handy for me one day if I ever need the same repair (assuming this person would agree to do the job again).

btw, your car is beautiful in Black Is it a 2.0 ? The part under the licence number look really different than mine, I never paid attention to that particular part of the car.

Best regards !

 

[DanielFriederich]

Hey Rolf

Well, and I like the red color of yours
It's a 2.0 Number 112 out of 250
67434 Neustadt is correct; the work has been done by a hifi electronics in Mannheim; but he declines to do it again (age 69...) due of too much work.
I would suggest to overwork the PEM before any BSM isolation faults or even worse the saturation faults occur. As I note already, if you don't be afraid of the disassembling work and the time to spent on it, it's pretty muy a DIY job.

It was the orange minus cable inside the "connector box" of the PEM; PEM will not start charging or driving and BSM will give you a BSM isolation fault error. They made this thing really idiot proof... D'Oh....
If you pass by at my place PN me

my best, Daniel

 

[DanielFriederich]

took a closer look on the rear. I actually like the 2.5 design more than the 2.0/1.5. Especially the rear looks much more "sophiticated".

 

[Rolf68]

Hi again Daniel

Ok I understand your technician wants to keep time for himself. I'd do the same I suppose if retired I'll start to look around here in order to prepare a "fix before failure" plan. The car is used daily and I now have 173 000+ km driven on the odometer. I suppose the PEM would be relieved with a new insulation. I'll talk with people at the service center as I'll have to bring the car for the annual service soon.

I think the 2.5 rear was renewed to accomodate the back camera. It also has what I think is called the "snow dam" feature, thus there are less debris entering the motor / PEM fans system.

I'll PM you if I ever drive to Neustadt. So far I never drove further than Strasbourg because of range limit, but if I include a night in a Hotel with a destination charger it may work someday in the future

Thanks for all and have fun on the electron road

Best regards

 

[dpeilow]

If you pass by at my place PN me

Is that Neustadt near Mannheim? I'm near there fairly often.

 

[DanielFriederich]

Yes its Neusatdt an der Weinstrasse. Feel free to pass by and PN me before... so I'm in
@Rolf: the snow dam has been installed in 2.0 also.

 

[Rolf68]

@Rolf: the snow dam has been installed in 2.0 also.

Ok, I didn't know So it must be for the camera only.

 

[dpeilow]

Yes its Neusatdt an der Weinstrasse. Feel free to pass by and PN me before... so I'm in

When I said often, didn't expect it to be this soon! Diverted through there 5 minutes ago thanks to that mess up in Baden Baden.

 

[DanielFriederich]

When I said often, didn't expect it to be this soon! Diverted through there 5 minutes ago thanks to that mess up in Baden Baden.

View attachment 242319

300m east you passed by my house and garden

 

[efxjim]

Latest Tesla Roadster Newsletter. Might be worth swapping out the caps as well.

There are several of us in San Diego/ L.A. thinking about a Pem Party.

 

[hcsharp]

There are several of us in San Diego/ L.A. thinking about a Pem Party.

Good idea.

 

[Msjulie]

any Bay Area thinking there?

 

[Jonathanm]

Still not quite there unfortunately.....

Having spent the last couple of months working in another country I finally got back last night to try the new plug (Service Disconnect) after I broke the first one. Well it resolved the alarms and I got the nice friendly chime indicating that the car could drive. As the car was up on jacks I could not move it but felt sure it would be ok.
But my joy was short lived. I plugged in to check the charging and I still get this loud buzzing noise like the contacter's vibrating very loud. It is quite disconcerting. When you plug in you hear the first of the contacters click in and then brrrrrrrrrrrrrrrrr....(loud)
The drive side now seems fine but what could be causing this on the charge side? I thought I checked all the fuses on the charging side but I will check again...

Anybody have any other ideas on what could be causing this?

As usual thanks to all....

Jonathan

 

[gregd]

Maybe one of the fans? Does it actually ramp up and charge, in spite of the noise?