Protection G - ABB SACE Emax 2 Series Installation, Operation And Maintenance Instructions

Protection G

t
G
I4
t4
88 | © 2013 ABB | 1SDH001000R0002 - L7804
Path
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Function
The protection G protects against an earth fault.
NOTE:
• The protection is available for the LSIG version of the release.
• With Ekip Touch, Ekip Hi-Touch and Ekip G Touch releases, if the protection is
activated the presence of the Gext sensor has been selected, it is possible to
adjust the protection in the Advanced section, under the Gext item. With Ekip G
I
Hi-Touch both the G and the Gext items are available, in the respective sections.
When the activation threshold is exceeded, the protection trips within a fixed or dynamic time
(the time decreases as the current read increases).
Parameters
The following is a description of the parameters:
Parameter Description
Activates/deactivates the protection.
If enabled, the protection is inhibited automatically by the release in two
conditions:
value.
Enabling
Determines the dynamic of the curve and the tripping time, fixed or
dynamic according to the selection:
The calculation of the tripping time of the inverse time curve is based
Function on a mathematical expression. The details are provided in the table on
page 94.
The value I4 contributes in calculating the tripping time, and also
defines the current value that, if exceeded, activates the protection (in
Threshold (I4) reference to the curve, it is the part parallel to the ordinate).
It is represented both as an absolute value (Ampere) and as a relative
value (In, nominal value defined by the Rating Plug).
The selected function determines the contribution of t4:
Time (t4) and the sending of the opening command.
the curve, t2 affects the entire curve, moving it along the vertical axis).
The protection G has Trip Enable, Zone Selectivity, Startup Enable, see page 93.
• Disconnection of one or more current sensors.
• Current measured on one of the phases is higher than a maximum
IMPORTANT: the maximum current value that deactivates
protection G 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).
• t=k (ANSI 50NTD): fixed time trip.
• t=k/i (ANSI 51N): inverse time dynamic tripping.
2
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.
• t=k: t4 is the delay time between the exceeding of the I4 threshold
• t=k/i : t4 contributes in calculating the tripping time (in reference to
4
ABB | SACE Emax 2
Ekip Touch protection release | 9 - Touch protections