Al vs. Cu

[ggunn]

Is there any reason why I wouldn't want to change over all wiring in PV systems from Cu to Al? Even for short runs, since we do a whole lot of them, it would save us a ton of $$'s.

 

[user 100]

Is there any reason why I wouldn't want to change over all wiring in PV systems from Cu to Al? Even for short runs, since we do a whole lot of them, it would save us a ton of $$'s.

I don't see where it would hurt anything at all- the same rules about al apply whether used in solar or in grid- oxidation concerns ( a non issue- the alloy today is different and there are solutions if really a concern- nolox, etc), al needs to be bigger to carry same amt of current than copper (so maybe larger raceways, but probably that xtra $$$ cancelled out by savings on copper), appropriate connectors/ terminations, don't nick the al.... and all that other good stuff you already know about.

 

[Carultch]

Is there any reason why I wouldn't want to change over all wiring in PV systems from Cu to Al? Even for short runs, since we do a whole lot of them, it would save us a ton of $$'s.

For circuits that are 100A and less, you will often find equipment that specifically requires copper. String inverters, MC4/H4 connectors, etc.


Over 100A, most terminations are dual rated for both Cu and Al, so it is less of a concern.

 

[310 BLAZE IT]

Aluminum on AC home runs is what we do. Depending on the length you may have to use reducers to make the terminations, since you're likely using a larger wire than the breaker typically allows for (both aluminum and upsized for voltage drop) It's hardly a downside but worth mentioning.

 

[pv_n00b]

As long as you follow the installation requirements you can use Al conductor. You may find, as Carultch wrote, that a lot of PV equipment that terminates smaller conductors is Cu only. Since Al is not usually used at smaller sizes the manufacturers do not add dual rated terminals.