Page 125 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

11 Compare the true energy & recorded energy which must be approximately equal.
12 Repeat the experiment for old energy meter and record & compare the values.
Parts of Energy Meter (Induction type)

R R
2 x
R R
Tabular column: 1 R 3
R 2 .R
Calibration of Standard Energy meter x R 1 3
Load Voltage Current Time Meter No. of disc True Recorded %Error
(V) (I) (t) Constant Revolution energy energy =

in sec (K) (N) TE =V x RE=N/K errror Percentage V V S 100 or I T I S 100
I
I x t V S I S
10% of full load 230 1500 50
current
50% of full load 230 1500 50
current
110% of full 230 1500 50
load current
Calibration of old Energy meter TR RE 100

10% of full load 230 3200 100 TE
current
50% of full load 230 3200 100
current
110% of full 230 3200 100
load current

Note: If error value is +ve, the meter runs fast
If error value is -ve, the meter runs slow
The % error must be less than + 3%
Safety precautions:
1 Do not make wrong and loose connections.

2 Do not exceed the load current of energy meter.
3 Do not make reverse connection of energy meter.

108

CITS : Power - Electrician & Wireman - Exercise 52