Quote Originally Posted by jaggedben View Post
Update...SolarEdge does not require a fused combiner. They said they thought LG required it.
Hmmm...SE seems to always avoid situations that will add cost to their systems.

LG seemed a little confused by the question. On the phone when I asked if a fused combiner was required I was told 'yes', but in a follow up email they stated that a junction box or combiner must be supplied, and that fuses are not required because the batteries contain their own circuit breakers. And yet they also recommended two fused combiner products. Based on the email I'm assuming I can just combine in a j-box with no fuses.
If the 2 battery packs are stacked or paralleled like PV strings, will a short in the output of 1 of the battery pack outputs feed into the short like in PV strings?

So in that case, what do my wires needed to be rated for? Here's my thinking:

There is no short circuit current rating on the data sheet. Conservatively I'd use the 25A rating of the internal circuit breaker for that. Alternatively I could use the peak current in the installation manual of 18.9A, but that doesn't exactly jive with Article 240.
Can you give a link to specs on the LG product? Are we looking at the RESU10H with the SE StorEdge?

Now, is a continuous use factor required? My thought is only for the operating current, which is listed as 14.3A (discharging). The peak current rating is listed as 'for 10 sec' so that's not continuous. So if using the 25A breaker rating, I do not need a continuous use factor.
I need to think about this.