I just got off the phone with Watts247. The tech there said there IS a bonding screw within the LV6548s that needs to be removed for US split-phase 240 operations, when using grid bypass....same as Growatts, so not truly US or UL out of the box.
Seems that removing the bonding screw within the inverters, and jumpering AC In/Out Terminal Neutrals will solve the issue. Followed up with email and will share any written reply.
Paul West
Thu 3/3/2022 1:21 PM
To:
Hi,
I just got off the phone with your tech there. He said there IS a bonding screw within the LV6548s that needs to be removed for US split-phase 240Vac operations, when using grid bypass (Utility Priority setting), and that this won't invalidate the warranties.
Can you provide either schematic or drawing of the exact location of the bonding screw? I wish to order 2 sets of your dual LV6548 inverters, need to need to know this first.
Others are experiencing ground loop current from these inverters and posting such on YouTube and DIY solar forums. It seems that the LV6548s have no issues when supplied by either solar or batteries. But when powered by Utility, the AC Output inverter panel terminals short N & G. This is not US/UL compatible!
Unless a special case (separately derived system as defined by the NEC), only the initial mains panel can be the single neutral to ground bond point. If I can remove the bonding screw (knowing exactly which one), then placing a jumper conductor between the inverter's AC In/Out Neutral terminals will then properly function within a US 240Vac split phase configuration.
Paul West