Yamatake SDC35, User Manual

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5-91
Chapter 5. DETAILED DESCRIPTION OF EACH FUNCTION
Handling Precautions
• Do not allow the current to exceed the upper limit of the CT input display
range. Doing so might cause a malfunction.
• If a current exceeding the upper limit of the CT input display range is
detected, the CT input failure alarm (AL11) is displayed. However, if the
excessive current is very large, the CT input failure alarm is not
displayed.
• The CT input display range and measurement current range change
according to the number of CT turns and the number of CT power wire
loops. Set for the number of CT turns and the number of CT power wire
loops suitable for the conditions of the CT connected. The display range
and the measurement current range are calculated by the formulas
shown below. (The internal calculations of this device have an error of
less than 0.1A.)
Display range lower limit (A) = 0.0
Display range upper limit (A) = Number of turns ÷ (16 x number of
power wire loops) X 1.4
Measurement current range lower limit (A) = Number of turns ÷ (2000
X number of power wire loops)
Measurement current range upper limit (A) = Number of turns ÷ (16 X
number of power wire loops)
The table below shows examples of how display range and measurement
current range change according to the number of CT turns and the number
of CT power wire loops. Measurement current range is shown in
parentheses.
• If ROM version 1 of the instrument information bank (
Id02
) is prior to
version 2.04, the operation is always performed on the basis of 800 CT
turns and one CT power wire loop. The number of CT1/CT2 turns and
power wire loops is not displayed and cannot be set.
• If ROM version 1 of the instrument information bank (
Id02
) is prior to
version 2.04, the CT input failure alarm (AL11) is not displayed.
100 turns 400 turns 800 turns 1600 turns 4000 turns
1 time 0.0 to 8.7A 0.0 to 35.0A 0.0 to 70.0A 0.0 to 140.0A 0.0 to 350.0A
(0.1 to 6.2A) (0.2 to 25.0A) (0.4 to 50.0A) (0.8 to 100.0A) (2.0 to 250.0A)
2 times 0.0 to 4.3A 0.0 to 17.5A 0.0 to 35.0A 0.0 to 70.0A 0.0 to 175.0A
(0.1 to 3.1A) (0.1 to 12.5A) (0.2 to 25.0A) (0.4 to 50.0A) (1.0 to 125.0A)
6 times 0.0 to 1.4A 0.0 to 5.8A 0.0 to 11.6A 0.0 to 23.3A 0.0 to 58.3A
(0.1 to 1.0A) (0.1 to 4.1A) (0.1 to 8.3A) (0.2 to 16.6A) (0.4 to 41.6A)
Number of
turns
Number of
power wire
loops