Why does my Open ESVE keep tripping, with overcurrent warnings in the control page, even when the set current is not particularly near the alleged 32A capability of the unit?
I am not completely certain but I think I have had trips at a set 27A or above in daytime. Overnight it seems even worse, with a trip at 26A. Overnight the voltage will be less without the solar to boost the local volts. Does that affect the tripping limit? The EVSE and PV are wired together on a long cable from the CU, that drops or rises by up to 4V locally.
Generally the indicated current is up to one amp less than the set current so it is not the case that the current actually drawn is higher than the set current.
There is some battery storage wired in there too but can’t see how that would affect tripping.
With the car disconnected/then connected to a 28A charge/ then a 32A one I get:
Pilot 6/6/6
Current now 0/27.5/27.75
Voltage 240.0/240.0/240.0
Max current 6/6/28
Service level 2/2/2
Level 2 min 6/6/6
Level 2 max 32/32/32
Sensor scale 220/220/220
The bold values seem like anomalies to me. The 6A might just be me not waiting for the reading to catch up. The 27.75 is probably because the battery is now pretty full and may not accept the full 32A.
After a few 10s of seconds at a set 32A it tripped on overcurrent. The message disappeared after a few seconds. This might be due to me changing the mode from a manual set value to a solar variable setting, rather than the Open ESVE automatically resetting itself. I note that even though the warning has gone it’s not returned to normal behaviour. In the past I have found I need to reboot it to clear the overcurrent. Or dis/reconnect the cable.
I am controlling this by issuing RAPI commands with my own processor and not vie the EmonPi setup.
Is it possible that as I have not updated the firmware (as advised here, I have 7.1.3EU) to read the cable resistor in my 32A non tethered cable that its not getting the pilot right? But why then is it perfectly happy to charge at up to around 25A which is way more than the pilot’s 6A?
Why does it stick at 240.0 V? Is that a set value rather than a real measurement? My nearby battery storage system recorded 256V, falling to 255V when the car drew 27.5A.
Anyone please got any new insights on this problem? I tried it again today on a set 28 A (26.62A as measured by EVSE) or 6471 W as measured by my independent monitoring system and it tripped after 10 mins.
I don’t understand why it’s not able to do 27 A or more without tripping. Have to power cycle the EVSE to get it to start again.
Have added 66% extra copper to the 20m long feed to it and it does not seem to make any difference to this problem. No evidence even before the increase that the volt drop is particularly significant.