Azbil C1M - Page 150

5-92
Chapter 5. Functions
Handling Precautions
• Make sure that the current does not exceed the high limit of the CT input that
can be displayed. Exceeding the high limit may cause malfunction.
• If this device detects a current exceeding the high limit of the CT input that
can be displayed, a CT input error alarm (AL11) will be generated. However, if
the current is so large that a malfunction occurs, the CT input error alarm will
not be generated.
• The display range and the current measurement range of the CT input vary
depending on the number of turns and power wire loops of the CT.
Make sure to specify settings that match the number of turns and power wire
loops of the connected CT.
The display range and the current measurement range are calculated using
the expression below.
(The calculation by 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 table below shows an example of the display range and the current
measurement range determined by the number of turns and 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)