I put it thru it paces today. With everything on in the house, 2 fridges, upright freezer, 2 under counter ice makers, ceiling fans, computers, hot water heaters etc it barely registered on the load meter and stayed right around 62hz. With it running the 5 ton AC, it ran steady at 50% power, it did spike the gauge and belch some smoke when the compressor kicked in, hz dropped to 58hz then went back to 60hz. The % of load meter I think is the wrong one, looks like ones on a MEP-002 but it was only $10...