"HELP" pv problems

[BruceB]

starting to panic now does this mean i should re-wire in bigger cable or by putting the gen meter beside the inverter will i get away without a re-wire

Putting the meter by the inverter hides some of the problem, but my tongue was firmly in my cheek when I said that.
I suggest you have to fix the design.

Regards
Bruce

 

[JulianC]

Another possiblity (not done any calcs so don't know how likely this might be) is that the volt drop in your cable is enough to send the output of your inverter up to its G83 trip limit under periods of high irradiation. It therefore could be tripping out when the sun comes out, hence the low generation figure.

 

[edexlab]

Isn't there something in the regs which says equipment installed should be to manufacturers instructions ,as long as this does'nt compromise BS7671
In most inverter manuals there's a reccomendation on cable csa and length of run ,some ie Sma sb 4000tl have a minimum cable size of 6.0mm

Cable cross section Max. cable length
SB 3000TL-20 SB 4000TL-20 SB 5000TL-20​

4.0 mm² 23.5 m not permitted not permitted
6.0 mm² 35.2 m 23.3 m 18.6 m​

10.0 mm² 58.7 m 38.8 m 31.1 m

 

[BruceB]

Isn't there something in the regs which says equipment installed should be to manufacturers instructions

It's stricter than that. 134.1.1 says "Electrical equipment shall be installed in accordance with the instructions provided by the manufacturer of the equipment."

Regards
Bruce

 

[DH Electrical]

My opinion is you will need to rewire the cable run in larger cable, as if the generation meter is moved closer to inverter it will cause meter to possibly be more accurate but you may still have volt drop

 

[edexlab]

It's stricter than that. 134.1.1 says "Electrical equipment shall be installed in accordance with the instructions provided by the manufacturer of the equipment."

Regards
Bruce

Thanks yes I knew i'd read it somewhere ,just did'nt have time to get brb out