Guru
Joined: 13/10/2014
Location: AustraliaPosts: 1860
| Posted: 03:25am 27 Apr 2025 |
PF With low House loads around 620W:
0.64
PF with 360W workshop fan added:
0.74
PF with 2.5kw Jug and house loads:
0.98
Is there a low power limit for reliably measuring Power Factor?
The HIOKI Power quality analyzer will not calculate PF below 1000W.
The HIOKI is measuring current, voltage and THD correctly down to very low power levels, but sets all Power Factor calculation to zero as soon as power is below 1000W.
It appears the small AC monitors are simply changing PF with power level below 600W, the lower the power the lower PF value.
Any thoughts or information would be appreciated.
Last bit of info: The THD is under 1.8% which is very good, I think around 8% is the upper limit for AC mains in AU?
Another last bit of info, the PF is the same on Mains AC at low power powering the same loads, removing the loads on at a time simply drops the PF each time, just follows the power drop until it indicates PF 0.1
It looks like I'm on the right track, I have two friends with totally different systems, they report the same thing below a certain power level, and they are using the same small AC monitors, it appears that the HOIKI indicates (by zeros) when results are crap and values are to low to accurately calculate PF, but the little AC monitors just show silly PF values that change with power levels below a set value.
.
Edited 2025-04-28 18:17 by KeepIS