Everyone,
To begin with , there is minimal amount of load on the system when the pumps are not running, just the RTU cabinet, and the power monitor reads as such: L1 =758.5 Watts, L2 = (-)241.9 Watts, L3 = 0 Watts, L1L2L3 = 516.6 Watts, the true power factor readings are L1 =(-)75.1, L2 = 25.2, L3 = 0, L1L2L3 = (-)24.4,
so I swapped the leads of the lighting panel transformer from L1-L2 to L1-L3. The readings now became L1 = (-)125.2 Watts, L2 = 0 Watts, L3 =650.9 Watts, L1L2L3 = 520.5 Watts, the true power factor readings became, L1 =14.02, L2 = 0, L3 = (-)75.1,
L1L2L3 = (-)30,
I then swapped the leads of the lighting panel transformer from L1-L3 to L2-L3. The readings now became L1 = 128.4 Watts, L2 = 644.8 Watts, L3 = (-)230.1 Watts, L1L2L3 = 542.2 Watts, the true power factor readings read L1 = 87.4, L2 = (-)68.6, L3 = 28.0, L1L2L3 = (-)28.01,
In conclusion; I have ruled out the possibility that the CTs are the wrong polarity, and I would say that there is a diffinate role in the connection of the lighting panel transformer, when the lighting panel transformer is de-energized the wattage readings are L1 =129.1 Watts, L2 = 0 Watts, L3 = 0 Watts, L1L2L3 = 131.0 Watts,
I can't say that I have payed much attention to the wattage on a power monitor in the past, but is this normal? Could there be anything wrong with the lighting panel transformer, something in the windings, or possibly something wrong with the panel or am I just seeing a phase shift. We are going from a 480 volt, 3 phase wye system, tapping off to a 480 - 240/120 single phase transformer, which must be playing a roll in a phase shift resulting in a negative wattage reading.
Most importantly, throughout this whole experiment or troubleshooting the amps and the volts have been right on exactly the same as what I read with my ampmeter and voltmeter.
Any thoughts or comments?
Thanks,
BC