Growatt Help Please..

morpheus75 · Dec 25, 2014

hello all
Just installed 2 growatt inverters. 10kw and 18kw
2 strings on 10kw inverter and 3 strings on the 18kw.
all working fine and well until yesterday at about 10.30am
18kw no problems all good and perfect but 10kw error code 30 which corresponds to AC Voltage out of range.
i checked the data as monitoring is setup and the AC volt readings are all around the 253v range on all 3 phases?
Vpv1 and Vpv2 are in range which tells me panels the DC side is all good aswell.

Any ideas please? This is my first 3 phase install and am stumped!

i have the downloaded data files for last 2 days if anyone wants them.
thanks

SibertSolar · Dec 25, 2014

What G59 settings/version have you selected? Were those phase voltage measurements taken from the inverter's data, or from measurements on the incomer? What distance from the PV DB and the incomer, and what size cable did you use? What volt drop calcs did you come out with, in terms of %?

morpheus75 · Dec 25, 2014

Inverter was preset on UK g59 both of them were. The measurements wwere taken from the inverter own data. 6mm cable used 9m length and volt drop calculated at 1.02%.
Circuit is as follows:
fuse to gen meter to isolator. Then cable goes to 1st isolator and loops 2nd isolator. Then 2 separate cables from isolators to the 2 inverters.
I have a feeling I may have undersized AC cable
thanks

SibertSolar · Dec 25, 2014

G59 /2 or /3? Volt drop doesn't seem excessive if your measuring 253vac LtoN at the inverter. If a reset doesnt rectify then sounds like a faulty unit. Why no individual overcurrent protection for each inverter/cable?

Does the inverter log not tell you an event listing for each phase's values at the time of the drop out?

morpheus75 · Dec 25, 2014

G59/3 and it doesn't give event log per phase. Not considered to put individual overcurrent protection in this case.
I will visit on site and read the actual display so far doing remotely but cannot get on site until after new year.
going to switch off 18kw and see results before contacting suppliers.
thanks

Gavin A · Dec 25, 2014

it will have a 10 minute average 253V trip setting, and will be on a commercial building with no power consumption over christmas, so the local voltage will be at it's highest level, so will trip out for those reasons.

6mm2 though for 28kW seems a bit on the low side - not that it will be causing the issue now, but peak summer on sundays it will exacerbate the issue.

There will probably be a way of adjusting the 10 min average voltage setting, as that's not part of the starndard g59 requirements exactly, though it does ensure compliance with the ESQCR voltage levels.