ABB | SACE Emax 2
Ekip Dip
3 - Protections - Introduction
37 | © 2023 ABB | 1SDH001000R0002 - ECN000297030
G Protection
G
I4
t
t4
I
G protection protects against a ground fault.
NOTE:
the protection is available for the LSIG version of the trip unit.
When the activation threshold is exceeded, the protection trips within a fixed or dynamic time (the time
decreases as the current reading increases).
Parameters
All the parameters that can be modified by the user affect the response curve, and related tripping times.
Parameter
Description
Enable
By setting the dip-switches of the threshold in one of the available
combinations other than Off, the protection is enabled.
If enabled, the protection is inhibited automatically by the trip unit under two
conditions:
• Disconnection of one or more current sensors.
• Current measured on one of the phases higher than a maximum value.
IMPORTANT: the maximum current value that deactivates G
protection varies according to the threshold set:
•
8 In (with I4 ≥ 0.8 In)
•
6 In (with 0.5 In ≤ I4 < 0.8 In)
•
4 In (with 0.2 In ≤ I4 < 0.5 In)
•
2 In (with I4 < 0.2 In)
Type of curve
It determines the dynamic of the curve and the tripping time, fixed or dynamic
according to the selection:
NOTE:
calculation of the tripping time of the inverse time curve is based
on a mathematical expression. The details are provided in the table on
page39.
Threshold I4
It defines the current value that activates the protection when exceeded (with
reference to the curve, it is the part parallel to the y-axis).
IMPORTANT:
•
The delay is interrupted if the current drops below the tripping
threshold.
•
For all the UL versions the maximum threshold allowed by the trip
unit is 1200 A. If a higher value is set, the trip unit signals the error and
forces the parameter to 1200 A.
Time t4
The selected function determines the contribution of t4:
• Fixed time: t4 is the delay time between the exceeding of the I4 threshold
and the sending of the opening command.
• Dynamic time: t4 contributes in calculating the tripping time (with reference
to the curve, t4 affects the entire curve, shifting it as a whole along the y-axis).
IMPORTANT:
•
The minimum tripping time of the protection is t4. If, according to
the calculation, the tripping time is less, it is automatically limited to
t4.
•
For all the UL versions, the maximum time allowed by the trip unit
is 0.4s. If a higher value is set, the trip unit signals the error and forces the
parameter to 0.4 s.
With the Ekip T&P module and with the Ekip Connect software it is possible to adjust the threshold of
Pre-alarm
.
