Question about G83 requirement of 16A each phase

LQY · Mar 21, 2012

Hi guys,

Some of PV installators told me that they want 4KW inverters with the max out put of less than 16A/phase. But G83 defines that is the reuqirement to systems less than 3.7kw. For 4kw, the safty should be G59. Could anyone tell me why some installators hope to get 4KW under 16A?

Thanks in advance.

LQY

LQY · Mar 22, 2012

Any one could help me with this question?

cbw · Mar 22, 2012

limited inverter

LQY · Mar 22, 2012

cbw said:
limited inverter

Could you please introduce to me more about this? Thanks.

cbw · Mar 23, 2012

Google for instance,

Aurora Power One PVI-3.6-OUTD 16A limited

or

SMA Sunny Boy 3800 16a limited

or

I think the G83 SMA4000TL is also limited to 3680, not sure

Just a some that I have used recently, like them both

BruceB · Mar 25, 2012

In response to the OP, the reason people try for 4kW is that is where the break in the FIT tariff is. Everything up to and including 4kW gets the highest rate. Therefore if you can install 4kW rather than 3.68kW and keep it on G83 you maximise your return on investment. Whilst the G83 standard is designed around 16A per phase, the G83 tests on inverters do not specify keeping the current below 16A. So it is possible for an inverter to be working in the G83 regime (in terms of under/over voltage and under/over frequency cut-offs) whilst actually working above 16A. In the past many DNOs were relaxed about this, but as more solar pv and other distributed generation is being deployed they realise they are making a rod for their own back offering the flexibility and so are now tightening up and keeping people within the 16A (3.68kW) limit. Going to G59 rather than G83 means prior negotiation with the DNO, potentially some network upgrade costs and often a more difficult design because for example the over-voltage limit is tighter (253V rather than 264V).
Regards
Bruce