Page 49 - MCCB-XT2-XT4

ABB | SACE Tmax XT

OV2 Protection Function
OV2 protection functions in the same way as OV protection: the protection sends a TRIP command if one
t or 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 76)
t16 • the graph with trip curve (page 86)
Parameters
V 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 OFF
information
Establishes the value that activates the protection.
Threshold
U16 The value is given as both absolute value (Volts) and relative value (Un) 1,05 Un
and 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
Time t16 5 s
and can 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 70).

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 protection can be activated in the Advanced – Signaling – Phase Sequence menu, while the required
sequence can be set in the Settings - Phase Sequence menu (page 27 and page 29).

VU Protection Function
The protection trips if the line-to-line voltages read by the unit are unbalanced; the protection sends a
t TRIP 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 76)
• the graph with trip curve (page 86)
V Parameters
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 OFF
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
Threshold 1% 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
Time t14 5 s
and can 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 70).

47 | © 2022 ABB | 1SDH002031A1002 - ECN000212994 Protections | 3 - Voltage protections