Start a new topic

OverTemp fault at minus 10 degC

My EVSE was working fine until the temperature dipped below -10C.  Now it is stuck in an over temperature fault.  If I query the evse through rapi the response is 2537 0 0.

253 degrees seems high for the cold day it is today.  :)

3 people have this problem

I disabled the temperature fault checking and the unit works fine now.  The temperature is reading 32 0 0 now as I suspect the sun was hitting it.  I'll check again after the sun goes down.  

I had a similar issue last week with my 50A unit.  What unit do you have (50A, 30A deluxe, 30A basic), which board version, and what firmware version are you running?

I believe this is a firmware bug, I am guessing the firmware does not know how to handle the sensor when the values go negative. As a temporary work around while the temperature is very cold, temperature monitoring can be disabled in the button Menu.

I believe I installed v3.10.4 but not sure.  I had a brief look around the source to see if I could find the location where the temp is read as I figured it might be related to the neg temperature but couldn't find it.  I'll keep looking since you confirmed my suspicions.

Temperature in Winnipeg is a frosty -19C (-2F)  and my 50A unit is showing red 'over temp' and my 30A basic unit has a red led, so I think I can confirm we have a firmware bug at low temps.  Running firmware V 3.10.4 on 50A, and 3.10.3 on 30A.  I've disabled the temp monitoring on the 50A unit with the button / menu, and will have to do the same on the 30A basic unit (without button so a bit more complicated).

Chris, I assume you are looking into a code fix or will have Craig K look into this.  Let us know when new firmware version is available and we'll test it out.  

Cheers, Jim

I am in Minnesota and experienced this same problem as it recently got really cold here.  My 50a deluxe is running 3.7.8 I do not see a menu option to turn it, the sensor off.  Is there a link on how to get different code in the unit and or how to compile firmware or download it etc .     I really like my unit, this is a little frusterating.
Thanks Tom


Tom What I did as suggested by Chris is to use the menu button to get to settings menu and then press it until you get to the temperature check menu and then change setting from Yes to No to turn off temp monitoring. I had no issues over this past weekend and temperatures were below 0F. This is a temporary fix until the firmware can be corrected. Here are the instructions for use of button. Button Menu The Menu options require an LCD and a button switch. The menu operates on Long press and short press. Long Press - Press and hold down Short Press - Press and release To access the menu press the button and hold it down until the menu displays. Scroll through the options with a short press the button. Change the value of an option Press and hold. Scroll through the available values for that particular option short press. Select the desired value Press and hold. Button Menu Options Note Menu options will not be displayed if the feature is not enabled when the firmware is compiled. LCD Type (Monochrome, RGB) Monochrome - Single Color LCDs RGB - Red, Green, Blue LCDs Service Level (L1, L2, Auto) L1 - Level 1 Charging Only (120v) L2 - Level 2 charging Only (200 - 240v) Recommended for International Users Auto - Auto Detect L1 or L2 Default Current (Options based on list in firmware) Vent Required (Enabled, Disabled) Ground Check (Enabled, Disabled) Set Time (Day, Month, Year, Hour, Minute) Start Time (Hour, Minute) Stop Time (Hour, Minute) are the instructions on use of the button Temperature check (Yes is enabled, No is disabled) Jim

3.7.8 does not appear to have this menu. Kind of a problem for those of us with an OpenEVSE that live in cold weather states. This is the time of year that reliable L2 charging is needed the most!

Anyway, I'm in the same situation as Tom. Looking for some guidance. Should I update to 3.9.10 to get the option to disable temp monitoring?

I would upgrade firmware to latest release in stable branch which is 3.10.4. Both of my units have been working fine in -25C weather with temp monitoring turned off. Jim
In a ticket I opened, Chris mentioned that users with 3.7.8 or earlier and without a programmer can unplug the display, and this will allow the charger to operate.


Lincomatic has posted a couple fixes:

The first is is for the sensor in the RGB LCD (included in 50A and 30A deluxe kits). I tested it last night and it works, there was a slight issue with temperature displayed the negative sign was added to both the whole number and decimal (-1.-7)

Today Lincomatic posted a fix for the display issue and fixed the MCP9808 sensor Color LED (included with recent 30A basic kits), it has not been tested yet.

Those who are setup with the development environment environment are welcome to compile and test. Pre-compiled HEX files will be posted after testing is complete, work around are disable Temperature monitoring in the menu or unplug the LCD/LED if running 3.7.8.

The fix for the negative temperature bug has been fixed and tested.

Here is a pre-compiled HEX with the fix for both sendors the DS3231 and MCP9808.

Firmware v3.11.3

and a Guide for loading:

Guide loading firmware


Same problem i had when temp drops around -10 /-15 Celcius.

Firmware 3.11.3 fixes the issue. 

Login or Signup to post a comment