[RE-wrenches] How to isolate the array DC

[Mark Frye]

In order to clear up the conversation...

I you put a relay in a box within 10 feet of the array on the roof, you 
can use an relay with a DC rated Normally Open contact to open and 
connect/isolate the array DC voltage.

You can drive the coil of that relay with either AC or DC, but either 
way, if you lose voltage to drive the coil, the contact opens and isolates.

My point is, for simple grid-tied system, there is no need for a "stop" 
switch anywhere in the system. It doesn't matter whether the contactor 
coil is driven by the premise AC or by a DC power supply connected to 
the premise AC, when the the main is opened or the meter pulled, the 
array Dc will become isolate.

Therefore, there is no need for the "stop" switch and yet as I 
understand it, such a switch is now required by the Code. The switch is 
not needed but is required.

Mark Frye