Page 66 - Sace Emax 2 Manual for design engineers

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ABB | SACE Emax 2
OV2 Protection Function
OV2 protection functions in the same way as OV protection: the protection sends a TRIP command if one or
t more line-to-line voltages detected by the unit exceed threshold U16 for longer than t16.
U16 OV2 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 93)
• the graph with trip curve (page 103)
t16
Parameters
V Parameter Description Default
Activates/deactivates the protection and its availability in the parameters
Enable OFF
menu
Activates/deactivates transmission of the open command: if disabled, the
Trip Enable OFF
alarm and exceedance of protection time are only managed as information
Establishes the value that activates the protection.
Threshold The value is given as both absolute value (Volts) and relative value (Un) and 1,05 Un
U16
can be set within the range: 1 Un to 1.5 Un in 0.001 Un steps
This is the trip time of the protection; the value is given in seconds and can
Time t16 5 s
be set within a range: 0.05 s to 120 s, in 0.01 s steps

Limitations and additional functions
The block functions can also be accessed by means of the service connector (via Ekip Connect) or by
connection to the system bus (page 83).

Phase sequence protection The Phase Sequence protection enables an alarm to be activated when the sequence of line-to-line voltages
is not aligned with the sequence set by the user.
The required sequence can be set in the Settings menu and the protection activated in the Advanced menu
(page 46 and page 44).

VU Protection Function
The protection trips if the line-to-line voltages read by the unit are unbalanced; the protection sends a TRIP
t command if the detected unbalance exceeds threshold U14 for longer than t14.
U14 VU The protection excludes itself if the maximum value of the line-to-line voltage is less than 0.3 Un
To check and simulate the trip times in relation to all the parameters, please consult:
t14 • summary table of the protections with the operating characteristics (page 93)
• the graph with trip curve (page 103)
V Parameters
Parameter Description Default
Activates/deactivates the protection and its availability in the parameters
Enable OFF
menu
Activates/deactivates transmission of the open command: if disabled, the
Trip Enable OFF
alarm and exceedance of protection time are only managed as information
Establishes the unbalance value that trips the protection.
Unbalance is expressed in percentage value and is calculated in the
following way: % Unba = 100 x (Δmax U ) / U in range: 2% to 90% in 1%
Threshold steps. mi mi 50 %
U14
NOTE: Δmax U : maximum deviation among the three voltages
mi
calculated by comparing each line-to-line voltage with the mean value;
U : mean value of the line-to-line voltages
mi
This is the trip time of the protection; the value is given in seconds and can
Time t14 5 s
be set within a range: 0.5 s to 60 s, in 0.5 s steps
Limitations and additional functions
The block functions can also be accessed by means of the service connector (via Ekip Connect) or by
connection to the system bus (page 83).

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