It feels strange to ask about this configuration within the the solar-oriented forum, but here it is:
Friends have asked me to recommend and possibly install a back-up only battery inverter-charger for their home, covering only bedroom lights plus a plug-in fan and kitchen lights plus the main fridge. (About 6000 watt-hours to cover the minimal loads for 4-6 hours per outage. I strongly prefer to build a 16s DIY LiFePO4 battery (I've done a few in the past). Backup only: Unlike my own grid-connected solar home, he will not have gird-tie with solar power pushing energy to the grid, and he will not be configuring for time-shifting.
Their concern is with NV Energy "extreme fire risk" blackouts in Incline Village NV USA (Near the California border, north Lake Tahoe). This is on the Nevada side (NV Energy) and not the CA side (PG&E). With no power ever being sent "backwards" (new permits, new meters, etc.), the installation can be completely downstream. I've identified 4 possible products so far, and I list here them with my "feelings of concern". Can you offer hints concerning these possible choices?
1) Schneider Conext XW PRO. It seems to have high reliability, but costs the most (by far) and might be a lot more challenging to configure. My feeling is "overkill".
2) Samlex EVO-4248SP. Seems fairly easy to configure. Split phase is not needed at their house. The neutral-ground bond in this unit is auto-switched, depending on whether the grid is present. (That's nice, compared to the issues being discussed "at considerable length" WRT the EG4 units). The 4200W power rating is lower but adequate, the inverters do have good headroom for starting up the household fridge compressor. The big question concerns the reliability of switching modes - back to grid pass-through when "the grid" returns. I do not see this small unit discussed much here, it is sized only a bit larger than some RV "all-in one" load centers. Does anyone have experience with it?
3 and 4) EG4 products (6000EX-48HV or 6500EX-48). They're very cheap, and I worry that a large proportion of the build cost is invested in un-needed MPPT SCCs, rather than the Inverter/Charger and the transfer switch. Their documentation materials indicate that they prefer to communicate with their own battery BMS, and this forum is filled with zillions of posts about "error 61' in communicating with those proprietary battery packs. (The packs themselves are sold at a reasonable price, but likely contain an inferior DALY BMS, and the cells aren't compressed. They're also small, just 100Ah each. I have built bigger and better battery packs.) I can certainly configure the 'User' battery mode, but I worry about (a) the Inverters running with unbalanced loads and (b) "issues" of bonding versus unbonding the neutrals to ground, and (c) it's ability to switch back to grid - including any possible "issues" with the 'neutral' current paths.
I'm inclined to recommend the Samlex, but hoping to hear from you all before I do that. The EG4 products are both fairly new, has anyone seen them successfuly switch back to grid when configured in UPS mode?
Thanks in advance.
Friends have asked me to recommend and possibly install a back-up only battery inverter-charger for their home, covering only bedroom lights plus a plug-in fan and kitchen lights plus the main fridge. (About 6000 watt-hours to cover the minimal loads for 4-6 hours per outage. I strongly prefer to build a 16s DIY LiFePO4 battery (I've done a few in the past). Backup only: Unlike my own grid-connected solar home, he will not have gird-tie with solar power pushing energy to the grid, and he will not be configuring for time-shifting.
Their concern is with NV Energy "extreme fire risk" blackouts in Incline Village NV USA (Near the California border, north Lake Tahoe). This is on the Nevada side (NV Energy) and not the CA side (PG&E). With no power ever being sent "backwards" (new permits, new meters, etc.), the installation can be completely downstream. I've identified 4 possible products so far, and I list here them with my "feelings of concern". Can you offer hints concerning these possible choices?
1) Schneider Conext XW PRO. It seems to have high reliability, but costs the most (by far) and might be a lot more challenging to configure. My feeling is "overkill".
2) Samlex EVO-4248SP. Seems fairly easy to configure. Split phase is not needed at their house. The neutral-ground bond in this unit is auto-switched, depending on whether the grid is present. (That's nice, compared to the issues being discussed "at considerable length" WRT the EG4 units). The 4200W power rating is lower but adequate, the inverters do have good headroom for starting up the household fridge compressor. The big question concerns the reliability of switching modes - back to grid pass-through when "the grid" returns. I do not see this small unit discussed much here, it is sized only a bit larger than some RV "all-in one" load centers. Does anyone have experience with it?
3 and 4) EG4 products (6000EX-48HV or 6500EX-48). They're very cheap, and I worry that a large proportion of the build cost is invested in un-needed MPPT SCCs, rather than the Inverter/Charger and the transfer switch. Their documentation materials indicate that they prefer to communicate with their own battery BMS, and this forum is filled with zillions of posts about "error 61' in communicating with those proprietary battery packs. (The packs themselves are sold at a reasonable price, but likely contain an inferior DALY BMS, and the cells aren't compressed. They're also small, just 100Ah each. I have built bigger and better battery packs.) I can certainly configure the 'User' battery mode, but I worry about (a) the Inverters running with unbalanced loads and (b) "issues" of bonding versus unbonding the neutrals to ground, and (c) it's ability to switch back to grid - including any possible "issues" with the 'neutral' current paths.
I'm inclined to recommend the Samlex, but hoping to hear from you all before I do that. The EG4 products are both fairly new, has anyone seen them successfuly switch back to grid when configured in UPS mode?
Thanks in advance.