Power Analyzer Erroneous Reading

[raehanar]

I have installed a Siemens PAC3200 power analyzer in a main power distribution panel which was observed to display an erroneous kWh reading. Upon further investigation, it was discovered that the power factor in one phase is abnormally low. Therefore, the VAR and W values are affected.

Following are sample readings recorded from the analyzer.
PF (Inst)
L1=0.84
L2=0.13
L3=0.92

An external power analyzer showed the L2 pf to be around 0.86. The internal control wiring of the system has not been scrutinized yet as we are awaiting a system power shutdown.

What could be the reason for this?

 

[davidbeach]

The L2 current or voltage is likely wired through the meter the wrong direction. Look at the phase angles.

 

[jraef]

Or, similar to above, the CT for L2 is mounted backward


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington