PowMr POW-SunSmart SP5K Low Output Voltage

[edmunc209]

Wondering if anyone has ever tried load testing these? I bought two of these to connect them for split phase operation. Each of these are rated at 5000 watts of output power with a peak power of 10000 watts. It seems like the more load I add, the output voltage decreases. When my load is about 3700 watts the output voltage goes down to 104 volts on each machine and a combined 208 volts for both. When I add another 800 watt load for a total of 4500 volts, each machine then goes down to 96 volts. Has anyone else experienced this? I'm wondering if these inverters just don't output the watts that it claims.

Looking around in the forum, there was a hint that the low output voltage issue could be a neutral ground bond issue. I just tested the resistance between neutral and ground at both of the inverters and there is a high resistance (no continuity), so it doesn't look like it's bonded inside the box. I also don't have a N-G bond at my breaker but I don't think that would cause this issue? Maybe a safety issue for sure ... Thoughts?

 

[Mattb4]

Your units may not be properly operating in stacked mode designed to keep each AIO output at 180 degrees apart. Double check your setup. If it is all correct than you likely need to talk to whoever you bought the AIO's from or PowMr regarding Warranty.

 

[edmunc209]

Hi Matt, thanks for your feedback. Are you thinking 120 degrees out of phase for 208 volts in a 3 phase operation mode? When I initially start the machine and add a small load I get the full 120v on each line and 240v combined. It's only when I start adding loads above 3k watts that the output voltage starts dropping. The more load I add, the more the voltage drops. Does that make a difference?

 

[Mattb4]

Load should not change output voltage. Individually the AIO's would fault if voltage is outside a value such as (+/-)5%* from inverter set point.

* the manual for my PowMr 3kW list this amount in the Technical specifications.