Diconnecting means when penetrating building envelope

[macdonaldtomw]

Hey all,

I am wondering about the need for installing DC and AC disconnects on the home run of a PV installation. I have heard that you need to install a disconnect any time you transition from inside the building to outside or vice versa. This is for Canada, though the NEC and the CEC are basically the same on PV from what I can see.

Consider the following scenario for example:

• 2 strings of a negatively grounded PV array and the grounding cable are run using type RPVU cable into a 4-contact rapid shutdown module that is mounted to the roof
• Inside the rapid shutdown box, the 2 strings are kept isolated (not combined)
• A 4 conductor TECK 90 cable is used on the output of the rapid shutdown module with 2 conductors carrying current from string A and 2 conductors carrying the current from string B.
• The TECK 90 cable penetrates the roof via a hole or Soladeck
• The TECK 90 is routed through the attic and out the attic wall to an exterior wall of the house
• The TECK 90 is run down the exterior wall and then penetrates through the basement wall into the mechanical room where the string inverter is housed.
• The string inverter output is fed to the electrical panel in the same room, using THWN cable or leftover TECK 90

Do I need a DC disconnect on the roof before the penetration?

Do I need a DC disconnect on the side of the house before the home run penetrates into the basement?

If so, can you refer me to the appropriate section of the NEC or CEC (preferable)?