Smart Solar 150/85 TR PV input terminal shorted , no error

DIY
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1

Good evening
One of my two SamrtSolar 150/85 TR seems to be faulty after an accidental cut off of the circuit breaker between battery and SmartSolars
The input termnals aeem to be shorted - checked panels and polarities eveything is ok. After waiting a couple of minutes and reconnection to the battery the unit perfectly reacts on VictronConnect ( through CERBO ) and also sends correct values via Modbus , no errors displayed ( error #0 ) , even performed a firmware update correctly
However, input terminals remain to be shorted inside the unit.
I have no idea what I can do now - are there any serviceable parts inside ? Can Victron repair or is there anybody out there to give an advice for diy repair?
Best regards Jürgen Scharfe
Doe anybody have an idea

2

This can happen if the input overvoltage protection is triggered.
There are several internal fets that can fail short to give this fault. An expert can sometimes repair a unit, but there is usually some problems gaining access for the repair.

3

Good morning Mike
Thanks for swift response
I have meanwhile performed PRE RMA Test
What shall I do ?
Best regards
Jürgen
114199-Pre-RMA_bench_test_instructions-pdf-en.pdf (186,0 KB)

4

Hi Mike,
Just another stupid question:
Would Victron recommend a circuit breaker between battery and SmartSolar chargers, if an unintetional break can cause damage to the chargers
Best Regards
Jürgen

5

Which panels do you use and in which string configuration did you put them in? A 150/85 can handle 150V PV input max, so your strings Voc should stay below that at all times

6

I have an old installation with two independent 2s5p groups of 10 panels with 170 W each ( max 44 V / 4.5 A ) the two groups can be are joined in parallel.

Each group consists of 2 panels in series and 5 Strings in parallel ( with 10 A fuses on string )

Overvoltage beyond 92 V ( which occurs only on a very cold day ) is impossible
Each group is also protected by a surge protection device for 150V DC

7

The date on your pre rma is wrong, its dated 2027 on last page

8

Forgot to say that the normally totally isoplated from each other and can only be joined by cable bridges
The isolation monitoring installed on the battery side does not detect any problem with isolation resistance

9

Sure this is wrong : 27 July 2025

10

Victron recommend a fuse in this line, mainly to protect the wire. The MPPT has a fuse internally, but this is nearly impossible to replace without wrecking the MPPT (cover). This is intended to prevent fire in the event of an internal short.

11

Thanks Mike,
So this means the unit is unrepairable ?
I have meanwhile sent a support request
Jürgen