Victron MPPT error help needed

[Jaaks]

Hi there

I have a Victron 250/100 mppt and used it quite hard today. Was doing around 4000 Watt solar power for a few hours with a constant high load. 

Around 12:00 I saw my batteries were draining heavily and went to investigate. The MPPT had switched off with error 26 "Power terminals overheated"

I did all the proper checks cables are 25mm2 and all connections are nice and tight. The system was quite hot. Tried firmware upgrade from 1.50 to 1.54 and switched off for a while disconnected panels for a while etc. But no luck. If I connect any panels the error comes back. 

It is now 17:00 everyrhing is cooled down and still same error. Is my MPPT done for? Still under warranty so just an inconvenience but not sure how to proceed? 

Any advice please. 

Multiplus II 5000 

250/100 MPPT 

3 strings of 4 x  410 Watt Canadians running at around 170 Volts

Cerbo GX

BMV 702

120Ah Lithiumbatteriessa.co.za battery

[Kalito]

Hmm that is interesting. I have the exact same inverter GX device and mppt. I have 10mm2 cable and 2 strongs of 5x430W monos. My only difference to your situation is that my lithium battery controls the mppt via the GX device on how it charges the battery. I have pushed 50A from the panels in an earlier configuration without any issue until I run into the Battery Voltage+5V dilemma and restringed to current config which gives it around 22A. I hit about 5100W and my peak load with load shift active is around 3,500W.

I assume you are pushing Isc of around 33A and your cable size is quite oversized so you shouldn't be having your current challenge. What is the ambient temperature of your Mppt location? Remember its air-cooled and if I am not mistaken its operating temp range must be upto 40 or 60deg?