Page 86 - Sace Emax 2 Manual for design engineers

ABB | SACE Emax 2
Gext Protection Function
Gext protection protects against earth faults and detects the fault current with a dedicated external toroid
t S.G.R.
I41 Gext
if S.G.R. toroid current exceeds threshold I41, the protection trips and, after a time established by the value
read and by the parameter settings, transmits the TRIP command.
t41 To check and simulate the trip times in relation to all the parameters, please consult:
• summary table of the protections with the operating characteristics (page 92)
I • the graph with trip curve (page 100)
Parameters
Sensor configuration is available in the Settings menu (page 46)
Parameter Description Default
External Toroid It allows the presence of external toroid S.G.R. to be activated OFF
Allows the reference current of the protection to be selected from
among four available quantities, from 100 A to 800 A
Toroid size IMPORTANT: the current selected from the menu must be 100 A
consistent with the size of the external toroid S.G.R.
connected to the unit

Protection configuration is available in the Advanced menu (page 44)
Parameter Description Default
Activates/deactivates the protection and its availability in the
Enable OFF
parameters menu
Activates/deactivates transmission of the open command: if disabled,
Trip Enable the alarm and exceedance of protection time are only managed as ON
information
Establishes curve dynamics and the threshold or trip time calculation:
Curve • t= k: fixed time trip t = k
• t= k/I : inverse time-delay dynamic trip
2
Establishes the value that activates the protection and contributes
towards calculating the trip time.
Threshold I41 0,2 In
The value is given as both absolute value (Amperes) and relative value
(In) and can be set within the range: 0.1 In to 1 In, in 0.001 In steps
It is the trip time or contributes towards timing calculation, depending
on the type of curve selected.
Time t41 0,4 s
The value is given in seconds and can be set within the range: 0.1 s to
1 s, in 0.05 s steps
Warns that the measured current is near to the protection activation
threshold.
The value is given in percentage of threshold I1 and can be set within
Threshold I41 the range 50% I41 to 90% I41, in 1% steps. 90 % I41
The prealarm condition deactivates in two cases:
• current lower than prealarm threshold I41
• current higher than threshold I41

Continued on the next page

84 | © 2020 ABB | 1SDH001330R1002 - ECN000134959 - Rev. A Ekip Touch - Protections | 9 - Additional protections and functions