1SDH002031A1002 ECN000092998 Rev. B
SACE Tmax XT2
– XT4 | 68
UC Protection
Function
UC protects the motor under reduced or no-load conditions: if all the currents read by units fall
below the Iuc threshold for a time greater than tuc, the protection sends the TRIP command.
To verify and simulate the trip times based on all the parameters, see:
Protection summary table with the operating characteristics (page 80)
Chart with tripping curve (page 95)
Parameters
Parameter
Description
Default
Enable
Enables/disables protection and availability on menu of the
parameters
OFF
Trip Enable
Activates/deactivates the open command: if disabled, the alarm
and the lapsing of the protection time are managed only as
information
OFF
Threshold
Iuc
Defines the value that activates the protection.
The value is expressed both as an absolute value (A) and as a
relative value (Ir), settable in a range: 0.5 Ir .. 0.9 Ir, con step 0.1 Ir
0.5 Ir
Time tuc
This is the trip time of the protection; the value is expressed in
seconds, which are settable in a range: 1 s .. 20 s, con step 0.5 s
1 s
Constraints, limitations, and additional functions
From the service connector (with Ekip Connect) or with system bus connection it is also possible
to access the block functions, see page 70.
U Protection
Function
U protects the motor in case of loss of a phase: if the rms value of at least one phase falls below
the threshold of 0.1 In and at the same time at least one current is greater than 0.25 for a time
greater than tu, the protection sends the TRIP command. The protection is inhibited during
Motor
start-up
.
If the U protection alarm occurs during
Motor start-up
, the trip unit calculates the trip time using
the lower value between tu and half of
Motor start-up
.
IMPORTANT: in this case, if the alarm occurs at start-up and the calculated TRIP
time is such that it persists even at the close of the Motor start-up window, the
trip unit still considers the minimum value previously calculated as TRIP time
To verify and simulate the trip times based on all the parameters, see:
Protection summary table with the operating characteristics (page 80)
Parameters
Parameter
Description
Default
Enable
Enables/disables protection and availability on menu of the
parameters
OFF
Trip Enable
Activates/deactivates the open command: if disabled, the alarm
and the lapsing of the protection time are managed only as
information
OFF
Time tuc
This is the trip time of the protection; the value is expressed in
seconds, which are settable in a range: 1 s .. 10 s, con step 0.5 s
1 s
Constraints, limitations, and additional functions
From the service connector (with Ekip Connect) or with system bus connection it is also possible
to access the block functions, see page 70.
Summary of Contents for SACE Tmax XT2
Page 84: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 84 L curve Ekip M Touch S curve t k I2 ...
Page 86: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 86 G curve t k I2 G curve t k ...
Page 87: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 87 IU curve UV curve UV2 curve ...
Page 88: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 88 OV curve OV2 curve VU curve ...
Page 89: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 89 S V curve S2 V curve RV curve ...
Page 90: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 90 UF curve UF2 curve OF curve OF2 curve ...
Page 91: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 91 RP curve D curve ...
Page 92: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 92 OQ curve OP curve ...
Page 93: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 93 UP curve RQ curve ...
Page 94: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 94 ROCOF curve R JAM curve R STALL ...
Page 95: ...1SDH002031A1002 ECN000092998 Rev B SACE Tmax XT2 XT4 95 UC curve ...