Line Losses Percentage

Depending on the quality of the three transformers they could be responsible for most of your losses right there.

Add in that most power meters running through VT and CT's can have a +- 2 - 5% variance between them and that could be your sources for the discrepancy right there.

Check these out for more information

http://www.opamp-electronics.com/tutorials/energy_losses_2_09_09.htm

http://nuclearpowertraining.tpub.com/h1011v4/css/h1011v4_56.htm

http://www.copper.org/applications/electrical/energy/trans_losses.html

Your plant may be riddled with loose joints, dodgy splices, undocumented taps and grossly undersized cabling for all we know.

Is the cabling warm to touch? Is there a persistent aroma of burnt bakelite and plastic? Do your connectors glow?......

Start looking and probing. Repeat your consumption monitoring starting closer to the MDB and do some accounting as you work your way towards the loads. Tabulate voltage and current and cable size/length values as you go. You will find the energy leaks. You won't be happy.

our cable sizing, connection , thimbling are ok. i want to know valid %age of line losses.

I strongly suspect the accuracy of the CTs & VTs as well as that of the meters. Pl. send them for calibration. Also, it is advisable to have all the CTs/VTs/meters of same accuracy class to get identical readings.

High levels of load unbalance produced greater losses while the same demand is maintained at each unbalance scenario. This means that network reconfiguration considering load balancing is highly recommend in order to diminish overall system losses.