Split phase 240v power calculation with WEM3050T trouble

Hello all,

I hope some one can help. me with my new installation of WEM3050T.

Here is my setup:

I have two of the CTs around each of input power lines from grid. Looks like everthing working correctly. Reading from each hot line and power cunsumption in home assistant matches exatly to what shows on the meter from the power company.

If you look at the picture attached you can see

Current A = 0.8A

Current B = 2.7A

Is this correct and normal? or do they need to be the same?

Other question is how is power(Watt) calculates? I know P=IV is the formula, but applying this to the readings does not add up!!!!!!

For example : Current A x Volatge A = Power A. Meaning 0.8A x 120.4V = 96.32W, but what shows in Power A is 73W !!!! this is automatically calculated and provided by WEM3050T. As seen ther is a difference of 23.32 between then. Not sure what I am missing.

I am running in to issues calculating accurate reading manually.

Dose any one know why? 

Thank you



Thread Status

Sort replies by:


In a split-phase system, there are two line (L) wires delivering power from the grid. The currents in these two lines are often unequal due to imbalances in the loads connected to each line.

When using a split-phase inverter, however, you'll notice that the currents in the two output lines are nearly identical. This occurs because the inverter's outputs are designed to be balanced. Consequently, we can use the measurement from just one phase to accurately estimate the total output of the split-phase inverter.

Like this https://www.iammeter.com/newsshow/blog-solar-grid-split-phase#configuring-the-ratio-of-phase-c

Regarding power calculation, the figure displayed represents active power. Active power is calculated using the formula: Active Power=U×I×Pf where U is the voltage, I is the current, and Pf (power factor) is the cosine of Φ, the phase angle difference between the voltage and the current.

I hope this clarifies how split-phase systems and inverters function and how power calculations are derived in these contexts.

Best regards,

Looks like you are new here. Register for free, learn and contribute.