[RE-wrenches] If anyone has input from an installer friend...

[Kent Osterberg]

Craig,

Just finished an installation that was sounds similar: grid connected 
house with a 20-kW automatic generator backup.  We decided against 
installing grid interactive inverters on the load side of the transfer 
switch.   The site had a 400-amp disconnect switch located before the 
automatic transfer switch because the transfer switch wasn't service 
rated.   Tap for the inverters is on the load side of the service 
disconnect before the transfer switch so the grid interactive inverters 
never see the generator output.   There has to be a fused disconnect for 
the inverters grouped with the service disconnect.

Kent Osterberg
Blue Mountain Solar


craig gerald buttke wrote:
> installers,
> so as to not reivent the wheel.
> any experience with connecting a grid PV system on the load side of an 
> automatic transfer switch?? fronius ig plus or sma's either one.
> the genset is a natural gas that modulates with load-- so it is a step 
> up from a menards portable type.
>
> assuming the solar is over producing the home usage (its a 10 kW 
> system so it could very well), the genset is still holding a "grid" 
> albeit at idle, the inverter will not necesarily know what to do 
> except keep wanting to produce "current (amps)".
>
> who has already tackled this??
>
> further there is talk of a battery system possible. but the 7 kW 
> genset would be stronger than a stacked pair of out back inverters, 
> and or too much capacity for the FM charge controllers to go to the 
> battery.
>
> comments?
>
> Thanks,
>
> Craig