VAMP 140 - Page 39

VAMP Ltd Overcurrent and earth-fault relay
Technical description
VAMP 140
VM140.EN011 Vamp 24h support phone +358 (0)40 573 6316
9
Figure 2.2.1-3 Normal Inverse (IEC 60255-3) characteristic.
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1
14,0
02,0
−
⎟
⎠
⎞
⎜
⎝
⎛
>
⋅=
I
I
k
st
t[s] = Trip time
k = Time multiplier
I = Measured current
I> = I set current