G59 Relay

[solarfred]

If we have 3 x 2500wp single string arrays on a 3 phase supply (split evenly over phases) using SMA 2500HF's will we need a G59 relay for sure or is it up to DNO? The SMA's are not G59 as far as I know only G83.

 

[SolarCity]

This would come under G83 as it is less than 16a per phase.

To be honest, unless you go to much bigger sizes the DNO is unlikely to ask for relays anyway.

 

[SolarRoofSols]

G83 for sure. you may be able to use a 8000TL 3 phase inverter, depending on the voltage of your strings. I don't have my info to hand but i am sure i asked sma about putting 4kw across 3 phases with this inverter and they said it would be ok - may be worth looking into.

 

[Worcester]

G83 post notify allows you to do up to 16 A / 3.68 kWp / phase , so even an STP10000TL is OK for post notify.

TedM berated the ENA a while ago and got this definitve answer:


The imbalance that is allowed between phases is

To ENA for a G83/1 Stage 1 Application
f) can you confirm the maximum Watts applicable to a 3-phase supply?

Answer:
f) 230x3x16= 11,040 for practicable purposes this is 11kW, split evenly over three phases. The following is not allowed
phase 1 4kW
phase 2 4kW
phase 3 3kW
as two phases exceed 16A per phase

Unbalance is allowable up to to the following limit
phase 1 3.7kW
phase 2 3.7kW
phase 3 any value under 3.7kW

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