4000TL - not set up correctly

[BruceB]

Bluntly, the design is poor.
- 16A mcbs are small for a 4000TL
- rcd main switch is not wise unless 200mA or more (ie 2 x 100mA because x2 inverters)
- 80m 10mm2 SWA is undersized
- 4mm2 is undersized unless very short

Assume both inverters were pushing out 16A, then the VD in the 80m SWA cable would be 12.5V (using TLC calculator). That ties in with your numbers, because your first inverter causes a voltage rise of 8V measured at the inverter. That will be 12.5/2 plus 1.75V from voltage drops in other cables in the installation and from the DNO's cable back to the transformer. That is way outside the 1% you are meant to be designing to on the ac side.

Biggs, you might be right that some inverters are set to cut out at 253V, but that is wrong in this country. The max voltage for the delivered mains at the service head here is 253V. The G83 limit for inverters to cut out in this country is 264V.

Fiador might just get away with the inverters operating at 261V if they are both set up right, but the smallest mains glitch would trip them.

Again using the TLC calculator, it looks like increasing to 16mm2 cable would give you a 7.42V drop at 32A so you would be 5V better off at the inverters.

Another option is to put the dc down swa cables and have the inverters near the service head.

It needs a proper re-design.

Regards
Bruce

 

[fiardor]

AS always guys you have been amazing and i will adhere to, learn from and implement most of the above (except move the inverters close to the main head as i would then have 80m of d.c to contend with lol).

This is the first job my company has done outside G83 and clearly this needs a lot more thought and designing rather than just doubling a residential 4KW system to 8KW to concur with G59.

Thanks again you two.

Fiardor.

 

[kmcgold]

contact sma get a personal sma grid guard code
you need to connect to the inverter and change the settings to g83 (locks the settings after 10hrs)
speak to dno for a 4kw system you might have to change the freq setting to 51.5 hz and 500ms

 

[kmcgold]

sorry didnt read all the threads

check resistance between l - n if over 1 ohms inverter shuts off
10mm for two inverters under sized if over 80 mtrs
do cable cals

 

[moggy1968]

The language problem is solved by moving a little jumper block inside the inverter. it tells you in the instructions. should have been done on installation. you shouldn't have to change the country settings dial if the inverter is UK spec supplied.

 

[Graeme Harrold]

The jumper block is there to over ride the counry specific settings, If set right on the dials, the language will also be set to suit.

 

[Deleted member 38070]

you'll have to get your installer to change the grid parameters as they will have to obtain a grid guard code to access the grid monitoring values, if its set to (a)5,(b)8 it will be set for uk with g83 compliant settings settings, that said i did have one that thought it was an sb5000tl and was not a happy bunny, so it might be a firmware c**kup, we had one which had to have the upper frequency cutout changed from 50.5 to 51.5 (western power) for this problem too.. bad news when the dno agree to specific values then move the goal posts... :-( when you find out what the problem was post it on here. what size system do you have is it over 3.68KWp?