ABB REF615 G - Page 836

t s
k A
B
U U
U
C
D
E
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=
⋅
×
− >
>
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GUID-6E9DC0FE-7457-4317-9480-8CCC6D63AB35 V2 EN (Equation 105)
t [s] operate time in seconds
U measured voltage
U> the set value of Start value
k the set value of Time multiplier
Table 661: Curve coefficients for the standard overvoltage IDMT curves
Curve name A B C D E
(17) Inverse Curve A 1 1 0 0 1
(18) Inverse Curve B 480 32 0.5 0.035 2
(19) Inverse Curve C 480 32 0.5 0.035 3
Section 11 1YHT530004D05 D
General function block features
830 615 series
Technical Manual