Seg HighTECH MRG3 - Inverse Time over Current Protection Relay

SEG Electronics GmbH Manual MRG3
84 DOK-TD-MRG3, Rev. D
7.8.12 Inverse time over current protection relay
According to IEC 255-4 or BS 142
Normal Inverse (Type A)


󰇡



󰇢





󰇟

󰇠
Very Inverse (Type B)


󰇡



󰇢



󰇟

󰇠
Extremely Inverse (Type C)


󰇡



󰇢





󰇟

󰇠
Long Time Inverse


󰇡



󰇢



󰇟

󰇠
RI-Inverse Time




󰇡



󰇢



󰇟

󰇠
*RXIDG – characteristic





󰇟

󰇠
Where: t = tripping time
t
I
> = time multiplier
I = fault current
Is = Starting current
ln = natural logarithm
*only for earth current