ABB | SACE Tmax XT
Protections | 15 - Additional protections and functions
75 | © 2020 ABB | 1SDH001821A1002 - ECN000135670
15 - Additional protections and functions
Introduction
Some protections have additional functions which extend their characteristics and performance:
Name
Type of protection
Page
Thermal Memory
overheating of the cables
Zone selectivity
management of trip commands in a network of circuit-breakers
Blocks
blocking of protection on the basis of programmable events
Startup
different thresholds on the basis of monitoring thresholds
Current thresholds
Current control with programmable thresholds
Programmable
Commands
Programmable commands with trip unit events or statuses
Installation of accessory modules allows the respective functions to be activated:
Name
Type of protection
Page
Gext
External earth fault with adjustable delay
Rc
Residual current
Synchrocheck
Synchronism between two independent voltage sources
MDGF
Modified differential ground fault
Thermal Memory Protection
The function, which is available for L and S protections, allows overheating in the cables connected to the
circuit-breaker to be prevented: in the case of trips within brief intervals, the unit considers the time between
commands and the entity of the faults so as to reduce opening time.
IMPORTANT: for the S protection the function can be activated if the selected curve
is time-dependent.
NOTE: the function also reduces the trip time in the case of overloads which have
not led to the open command (longer than 100ms)
S, S2, I, 2I, MCR, G, Gext,
MDGF zone selectivity
Protection
The function, which can be activated for S, S2, I, 2I, MCR, G, Gext and MDGF protections (if available and
enabled), allows several devices belonging to the same installation (including Ekip Touch) to be interconnected,
so as to handle trip commands in the best possible way in the case of S, S2, I, 2I, MCR, G, Gext and MDGF
protections.
The function allows the devices to be coordinated so that, if a fault occurs:
• the device nearest to the fault trips
• the other devices are blocked for a programmable time
NOTE:
connection can be made between ABB devices that have the zone selectivity function
Characteristics
Ekip Touch has five selectivity connections, located on the rear connectors of the CB:
Name
Type
Description
Connection
Szi
Input
S, S2, I, 2I and MCR protection selecitivity input
From devices on the load side
Szo
Output
S, S2, I, 2I and MCR protection selecitivity output To devices on the supply side
Gzi
Input
G, Gext and MDGF protection selectivity input
From devices on the load side
Gzo
Output
G, Gext and MDGF protection selectivity output
To devices on the supply side
Szc
Common
Common connection of selectivity network
The entire selectivity network
Continued on the next page
