First time poster here.
I'm trying to be able to have a backup battery system for (rare) grid failures. I'd like to run frig and freezer circuits minimum as well as be able to pump our deep well. Evidently, that's where it gets challenging. We have a Franklin 1 HP pump sitting about 400 feet deep. It is a 3 wire pump. On the control box it says 8 Amps. I took that at face value (OK, now I've learned different). I figured OK, even 10A at 240v = 2400 watts. I bought an EcoWorthy 100A 51v server rack battery and a Wzrelb 4000 watt split phase inverter. It runs my frig and freezer circuits fine, but refused to start the well pump. Looking around here a little, I realized I needed an inrush reading, ordered a meter from Amazon, and (ouch!) 37A on both of the hot legs. OK, that hits in at 37 x 120 x 2= 8800 watts. No wonder the inverter (with stated 2x surge capacity) didn't cut it.
I started looking at higher power inverters, and actually ordered one (from Amazon), until I got to thinking about battery power needed, and that's what I'd like someone to confirm for me and my calculations. In the EcoWorthy manual, it states that Maximum discharge current is 100A, so doesn't that mean that I can only get 100a x 51v = 5100 watts from the EcoWorthy, and thus I appear to be short on both inverter and battery power here?
Even if I order a 2nd EcoWorthy and a bigger inverter, don't I still need 8800 / 51 = 174A for startup surge (from the battery) for the pump? Also, in an actual power outage, once I ran the frig and freezer for a few hours, I'd no longer have 174A left, and thus could only run the pump very early in the outage?
Can someone confirm these conclusions? I've since canceled the bigger inverter order to look into this more.
Thanks, David
I'm trying to be able to have a backup battery system for (rare) grid failures. I'd like to run frig and freezer circuits minimum as well as be able to pump our deep well. Evidently, that's where it gets challenging. We have a Franklin 1 HP pump sitting about 400 feet deep. It is a 3 wire pump. On the control box it says 8 Amps. I took that at face value (OK, now I've learned different). I figured OK, even 10A at 240v = 2400 watts. I bought an EcoWorthy 100A 51v server rack battery and a Wzrelb 4000 watt split phase inverter. It runs my frig and freezer circuits fine, but refused to start the well pump. Looking around here a little, I realized I needed an inrush reading, ordered a meter from Amazon, and (ouch!) 37A on both of the hot legs. OK, that hits in at 37 x 120 x 2= 8800 watts. No wonder the inverter (with stated 2x surge capacity) didn't cut it.
I started looking at higher power inverters, and actually ordered one (from Amazon), until I got to thinking about battery power needed, and that's what I'd like someone to confirm for me and my calculations. In the EcoWorthy manual, it states that Maximum discharge current is 100A, so doesn't that mean that I can only get 100a x 51v = 5100 watts from the EcoWorthy, and thus I appear to be short on both inverter and battery power here?
Even if I order a 2nd EcoWorthy and a bigger inverter, don't I still need 8800 / 51 = 174A for startup surge (from the battery) for the pump? Also, in an actual power outage, once I ran the frig and freezer for a few hours, I'd no longer have 174A left, and thus could only run the pump very early in the outage?
Can someone confirm these conclusions? I've since canceled the bigger inverter order to look into this more.
Thanks, David