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External Temperature sensor inputs?

hey there,  i know you have the built in temp sensors on the board and the lcd.   do you have or have you thought of a serial attached external board with a few solder inputs for external temperature sensors?   I have seen a few EVSE's that monitor contactor electrical terminals for heat, since this is the most likely area to fail and cause fire, I wanted to add a few terminal temp sensors to my contactor and shut down on high temp if there is an issue.    But I think you only use the IC's with built in temp sensors today.   just a thought.   some kind of external serial board that could read 10k thermistors would be cool.  

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Something like this would work... https://www.sparkfun.com/products/15334


We would love to see temperature sensors on the EV connector power pins and input plug power pins as well.


The OpenEVSE generic enclosure internal temperature does a good job of monitoring relay connection/contact temperature. It is the biggest source of heat. Overheating contacts drives up the internal temperature very quickly. But the more measurement points the better.

But this requires programming, correct? I had one of my contactors burn up, not long ago, and I had no clue till I took it apart to put on some new charging handles and cords. It was still working but pieces of the contactor had gotten so hot cracked and fell away and there was no insulation on the power wires for a good inch and a half. It was all melted away, but they didn’t touch ground so it kept working I would like to prevent, this in the future though this particular issue was a mechanical failure, also not caught by the EVSE temp sensor, having them on the terminals would be awesome. What is the set point when you start throttling power output?

Yes, a library would be needed to read the ADC inputs and code to decode and act on the inputs.


Your configuration is a bit different. The temp sensors are on the displays, which I believe are in a different location from your relays. 


For a no code fix, you may want to remove the chip from the displays and add this to the relay area inline with your displays. The relay area would need to be relatively sealed for it to work though. 


https://www.adafruit.com/product/5027

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The relay is in a small cube with the open EVSE main board. (No sensors on the main board? Thought there was) but that small sealed cube is all cast aluminum and the whole rear is a heat sink. Contactor is mounted directly to the heat sink case. Humm. I use the display and rgb led but like you said they are in a different case from the controller and contactor. I suppose a second rgb led inside possibly attached to contactor prob wouldn’t read right? Where are these various temp sensors listed in the screenshot and what is sensor 3?
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To be clear, on the previous post. My question got buried. Where are these various temp sensors listed in the screenshot and what is sensor 3?

Temp 1 is from older LCDs with Real time clock from the DS3231.

Temp 2 is from a temp sensor on newer displays MCP9808.

Temp 3 is from an older discontinued IR temp sensor. 

Temp 4 is from a WiFi MCP9808. This sensor runs hotter due to heat from the WiFi chip.

is there any way to have the board you suggest above show up/work with temp 3?   and does the programming even care about temp 3 when throttling the current?    or is that only temp 1 that has an effect?   

The Adafruit Board above is based on the MCP9808, If connected inline with the display on its default address it would show up as Temp2 and would work for throttling. If your display already has a temperature chip, it would need to be removed.


The Sparkfun board combined with the 10k thermistor would require a library and significant changes to the source code.


Oh, I follow what you are saying now, yes, as you can see in my Screenshots, mine already has temperature sensor number two. I guess I can just find that IC and cut the data pin, correct? I assume it’s surface mount and I don’t have a good way to cleanly remove a surface mount component without potentially destroying stuff around it. Sorry to be a pest about this lol but do you have the schematic for the display and I will perform some surgery and order some parts and let you know how it goes.
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