[RE-wrenches] Delta lightning arrestors

[Brian Mehalic]

Hey wrenches, I have a couple of Delta LA questions. 

On the DC side there is an arrestor connected directly to the busbars in each combiner box. Each combiner is 24 strings and runs through a 300 A OCPD in the inverter sub combiner where it is paralleled with 7 other PV output circuits. 

On the AC side, there is an arrestor connected to the load side busbars in an 800A fused disconnect (actually there are 7 disconnects, one per 500 kW inverter). 

Deltas installation instructions are woefully inadequate. Something sure seems wrong about connecting a 12AWG conductor to a 300A OCPD, let alone an 800!

Any input would be much appreciated regarding the correct installation method.  Also it appeared the DC one was listed by ETL but the AC one was not? 

Note: it wasn't my choice to put them in but they're in now and I want to make sure it is safe for general operation (I'm sure we can debate their value and safety as surge protection, but that's not my question here). 

Thanks,
Brian