electrical energy calculation in 3phase

[lokesh.dee]

HI

I have a MCC panel it is showing KW reading for each phase L1,L2 and L3 are 4.7KW,4.0KW and 4.2 KW repectively. the energy consumption for 2 hours was 16 Kwh.how come it is possible

my doubt is my load was stable for 2 hours with 10-15% variation i should be 8-10 Kwh for 2 hours why it is 16??do we have to consider sum of 3 phases power??? or average of them??

 

[Knobhead]

If you are reading KW on each phase then for 3Ph it the sum of the phases. Just be sure you are reading KW or KVAr on all meters.

 

[lokesh.dee]

thank you!!

I am sure that it is K W . if it is sum it should be 24KWH for two hours right??!! because the load was stable for 2 hours

 

[Knobhead]

How are you taking these readings at the moment?

 

[lokesh.dee]

there is energy meter installed in the panel i wanted to compare the kw and kwh reading so i have asked this generel question

tell me in generel total KW of a motor = L1KW + L1KW + L1KW


if it is the case where we can find supporting theory??

 

[Knobhead]

You need to take efficiency and power factor in to account. The KW rating of a motor is the output at the shaft.

 

[lokesh.dee]

how can we take efficiency??

 

[lokesh.dee]

While a 3 phase motor running which is connected to particular panel kw reading is showing only for one phase l 1. My doubt is on energy meter why that is showing only one ohase kw ??!!!

 

[lokesh.dee]

thank you