You are quite correct SJB since the cosine of 0 deg is 1, I was just showing the calcs based on the face plate label, I don't seem to be able to get into the electrical forum to post a query re the apparently very high PFs of the old type traditional circ pump motors. I thought originally that the starting capacitor was "left" in the circuit but was able to disprove this on a old Salmson unit, not the above one.
For example, take my own Wilo ST circ pump (~ 11 years old) powering my solar system, the PFs for the 3 speeds, starting at the lowest are, by my calculations, respectively, 0.93, 0.88 & 0.99. My A rated Wilo Yonos Pico CH circ pump motor gives a measured 0.53 which IMO is more to be expected but all the pump manufacturers were hardly posting incorrect numbers.
Some electrical people who are reading this might care to comment or I can repost it in the electrical forum if someone points me in the right direction
The attachment is a bit hazy so the numbers are, 230V/0.20A/43W, 230V/0.3A/61W & 230V/0.36A/82W
For example, take my own Wilo ST circ pump (~ 11 years old) powering my solar system, the PFs for the 3 speeds, starting at the lowest are, by my calculations, respectively, 0.93, 0.88 & 0.99. My A rated Wilo Yonos Pico CH circ pump motor gives a measured 0.53 which IMO is more to be expected but all the pump manufacturers were hardly posting incorrect numbers.
Some electrical people who are reading this might care to comment or I can repost it in the electrical forum if someone points me in the right direction
The attachment is a bit hazy so the numbers are, 230V/0.20A/43W, 230V/0.3A/61W & 230V/0.36A/82W
Attachments
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