[Solar/PV] Supply Line Side Connection

[KevinKos]

Hello all, I have a question.

We are designing a system to feed a total of 132 Enpahse IQ 7 Microinverters. 132 amp x 1.25 = 165amp

The existing feeder from the meter to the house MSP is 4/0 aluminum.

From my combiner box to ac disco, and ac disco to MSP(supply side connection). Thinking about using copper 2/0. is it up to code to tap aluminum 4/0 with copper 2/0? I couldn't find a section for this rule. can someone please help?

 

[augie47]

110.14
Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical
contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use


Can be done.. just need the correct connector.

 

[Canton]

There are numerous insulation piercing tap connectors out there now for this. The tap/feeder don't make direct contact and they are listed for copper and aluminum. Polaris is one brand in particular.

 

[Carultch]

You essentially need a connector that has a separate section for each conductor, if there are dissimilar materials of conductors you are tapping together. Such as Polaris blocks, or insulation piercers as Canton showed as an example. Most people would do that anyhow.

What would not comply, is connectors that require the wire to directly touch. Such as ordinary split bolts without a separator bar, or lugs rated for two wires in the same opening for wires (e.g. snowman lugs). If you had terminations such as this, you could only mix wires of the same material, and rated for use with the lug. This is what the separator bar in the split bolt is meant to do; to separate dissimilar metals on both sides of the connector, and buffer them with a tin-coated separator that is rated to interact with both.