FANOX SIA-C, User Manual

Page: 73 / 188

www.fanox.com Rev. 26 73/188
4.11. IEC60255-151 Curves
The SIA-C relay complies with the curves shown in standard IEC60255-151:

Inverse Curve

Very Inverse Curve

Extremely Inverse Curve

Long time inverse
There is a general mathematical equation that defines the time in seconds as a function of the
current:
K D B
Q V
D A
t
P
  



adjusted
I
I
V

Parameters A P Q B K
Long Time Inverse 120 1 1 0 0
Ext. Inverse 80 2 1 0 0
Very Inverse 13,5 1 1 0 0
Inverse 0,14 0,02 1 0 0
The curve can mode from its axis using the D time selection device, which the user can adjust.
I
adjusted
is the initial operating current, set by the user.