4-82
Chapter 4. Functions
z
CT input display range and current measurement range
The display range and the current measurement range of the CT input vary
according to the number of turns inside the CT and the number of power wire
loops through the CT.
Set numbers that match the number of turns and the number of power wire loops
of the connected CT.
The display range and the current measurement range are calculated using the
formula below.
(The internal calculation of this device has a margin of error of 0.1 A or less.)
Display range low limit (A) = 0.0
Display range high limit (A) = Number of turns ÷ (16 × number of power wire
loops) × 1.4
Current measurement range low limit (A) = Number of turns ÷ (2000 × number
of power wire loops)
Current measurement range high limit (A) = Number of turns ÷ (16 × number of
power wire loops)
The following table shows an example of the display range and the current
measurement range with the number of turns and the number of power wire
loops of the CT. The current measurement range is shown in parentheses.
Number of turns
Number of
power wire loops
100
400
800
1600
4000
1
0.0 to 8.7 A
(0.1 to 6.2 A)
0.0 to 35.0 A
(0.2 to 25.0 A)
0.0 to 70.0 A
(0.4 to 50.0 A)
0.0 to 140.0 A
(0.8 to 100.0 A)
0.0 to 350.0 A
(2.0 to 250.0 A)
2
0.0 to 4.3 A
(0.1 to 3.1 A)
0.0 to 17.5 A
(0.1 to 12.5 A)
0.0 to 35.0 A
(0.2 to 25.0 A)
0.0 to 70.0 A
(0.4 to 50.0 A)
0.0 to 175.0 A
(1.0 to 125.0 A)
6
0.0 to 1.4 A
(0.1 to 1.0 A)
0.0 to 5.8 A
(0.1 to 4.1 A)
0.0 to 11.6 A
(0.1 to 8.3 A)
0.0 to 23.3 A
(0.2 to 16.6 A)
0.0 to 58.3 A
(0.4 to 41.6 A)
