— 5 —
IM 2042-01
(4) 電流，電圧ともに定格値をこえる場合の三相電力測定
Fig. 2-4 のように電流回路に変流器，電圧回路に変圧器を接続し
て測定します。
負荷電力 (Watt) ＝ 計器の読み×乗数×変圧比 × 変流比
＜計算例＞
計器使用レンジ：
120 V, 5 A
乗 数：
10
計器指示：
100
変圧比：
6600/110 V
変流比：
50/5 A
6600
110
50
5
×
= 100 × 10 ×
= 600 000 watt (W)
= 600 kwatt (kW)
負荷電力
4. Three-phase power measurement where both the voltage and the
current exceed their rated values
Connect a VT to a voltage circuit and a CT to a current circuit as shown in
Figure 2-4.
Measured power (watt)
= indicator reading × range multiplier ×
VT ratio × CT ratio
Example:
Instrument terminals connected:
120 V at 5 A
Range multiplier:
10
Indicator reading:
100
VT ratio:
6600/110 V
CT ratio:
50/5 A
Measured power (watt) = 100 × 10 × (6600/110) × (50/5)
= 600 000 watts (W)
= 600 kilowatts (kW)
±
±
Fig. 2-4
電源
Power Source
R
S
T
CT
負荷
Load
V
v
U
u
V
v
U
u
VT
VT
L
K
k
CT
L
K
k
Summary of Contents for 2042
Page 20: ...Printed in China ...
