DNOs and G83 limit

[officerdibble]

It is quite easy to install 4kWp installations and get within even the strictest DNO requirements, you know, the mad ones stating 3.68kW. Always state on the G83 form that the maximum generation ability is not greater than 16A.

This can be verified on the following basis.
Maximum DC generation capacity is 4kWp
Efficiency of inverter eg 95 %
Supply voltage = 243V

Make the calculation and the maximum generation capacity of the SSEG is (4000x0.95)/243 = 15.638A

Shimples Eek!

 

[TedM]

G83 16A limit is based on 230V and that figure should be used in the calculation.

 

[Worcester]

@officedibble,

Can't do that our certification is too important to us!

Either less panels, or the inverter has to be limited and since it faces west, I'm loath to reduce the number of panels for an artificial reason.

Found the inverter anyway, its the SMA SB3800V (the V is the important bit) it has a continous rating of 16A, specially made forthe UK market, so it complies with the GB83 limit, and the system output is within the parameters of the inverter.

 

[officerdibble]

G83 16A limit is based on 230V and that figure should be used in the calculation.

An interesting reply, please direct me to the specific paragraph which makes this directive. I possess G83 I will have another look at it.

Whether or not G83 states 230V the facts are quite clear, the mathematics speak for its self. Is this an arbitrary figure or is it backed by a clear calculable physical facts. 16A at 230V is fine, does G83 refer to the maximum current at 240V. Simple answer - NO.

 

[TedM]

The Electricity Safety, Quality and Continuity Regulations 2002 - The Electricity Safety, Quality and Continuity Regulations 2002

Parallel operation
22 (2) (a) the source of energy does not produce an electrical output exceeding 16 amperes per phase at low voltage;

Declaration of phases, frequency and voltage at supply terminals
27 (2) Unless otherwise agreed in writing between the distributor, the supplier and the consumer (and if necessary between the distributor and any other distributor likely to be affected) the frequency declared pursuant to paragraph (1) shall be 50 hertz and the voltage declared in respect of a low voltage supply shall be 230 volts between the phase and neutral conductors at the supply terminals.

http://energynetworks.squarespace.com/storage/DGCG G83 S1 Nov2010.pdf

SSEG is defined as

a source of electrical energy rated up to and including 16 A per phase, single or multiple phase, 230/400 V ac.

ER G83 is just another document that embodies and expands on these regulations.

 

[Graeme Harrold]

SP Energy Networks reqiuire G83/1-1 Ap2 in advance for systems exceeding the 3.6KW. Im fitting a 3.9KW system and will have to ensure my SMA inverter is reset to to G59 limits - 51.5Hz for 0.5 sec. If this is confirmed there is no need for a site visit or the associated relays.

My contact was a Mr Oldfield and was extremely helpful.

 

[Worcester]

@ Graeme Harrold

If the inverter is limited to 16A / 3.68 kW no need for an App2. Only inverters I'm aware of (so far ..) that meet this are Diehl Ako 4300S and the SMA SB3800V (Note the V)

Only problem with the SB3800V is single MPP Tracker, DA quite old tech.

We have a west facing install 3.99kWp that will never achieve 3.99. Western Power Distribution, nee Central Networks, OK with App3 if use an Inverter of that type, else must be App2.

 

[solarfred]

K-Mate HESI3800GT is limited to 16 amps. G83 certificate. Single tracker with two inputs. No fan to burn out as it is a heatsink version.

 

[avonsolarltd]

I have just installed 3.77kw on my roof as after speaking to my DNO Western power, all they kept saying was 16 A. I quizzed them about the supply voltage they said it had to be worked out using 230volt. My incoming mains is 236volts which I pointed out and they kept saying 16amps.
They really don't have a clue there needs to be something put in place asap. Lets hope 1 of them reads this.

 

[officerdibble]

230V is a nominal value, current is totally dependant upon actual voltage levels, therefore you cannot state 16A max and insist that it is worked out on 230V as the actual value will be different. G83 states maximum 16A. The DNO's actually have the discretion to connect up to 20A on G83 anyway. In most cases they will allow 4kWp systems. This is such a problem for the industry that I understand it is on the agenda for the next ENA meeting of DNO's.

Lets be clear about this, the only stated maximum G83 states is 16A it does not state max size in kW's. ENA created this problem it's time they put it right.