Hi. I'm a retired engineer getting involved in my first solar PV installation. The initial installation is straightforward: 2 strings of 10 modules each using Enphase microinverters, combined in a Soladeck box, with 20A breakers on each string. This meets the old requirement that the breakers add to 40 or less amps for a 200A service. No problem.
However, in a few years we plan on adding a third string (32A total output). Under the new 2014 NEC (section 705.12(D)), we will be able to simply add a third breaker to the Soladeck and pass the 3rd string through it. However, under previous NECs we would have to jump through some hoops reconfiguring the arrays, with more branches and junction boxes. We could build for that now, complicating the initial installation, or keep things simple in anticipation that the 2014 NEC changes will be widely accepted in a few years.
What would you do? Keep initial installation simple, anticipating NEC 2014 acceptance (i.e., that the old method of adding up breaker sizes will go out of favor), or complicate the initial installation so that it works no matter what? (My inclination is to keep it simple, esp. since it doesn't make any electrical sense to me to be adding up breaker sizes vs. use of the inverter's actual AC output current.) thanks
However, in a few years we plan on adding a third string (32A total output). Under the new 2014 NEC (section 705.12(D)), we will be able to simply add a third breaker to the Soladeck and pass the 3rd string through it. However, under previous NECs we would have to jump through some hoops reconfiguring the arrays, with more branches and junction boxes. We could build for that now, complicating the initial installation, or keep things simple in anticipation that the 2014 NEC changes will be widely accepted in a few years.
What would you do? Keep initial installation simple, anticipating NEC 2014 acceptance (i.e., that the old method of adding up breaker sizes will go out of favor), or complicate the initial installation so that it works no matter what? (My inclination is to keep it simple, esp. since it doesn't make any electrical sense to me to be adding up breaker sizes vs. use of the inverter's actual AC output current.) thanks