B2342
Emax VF
39/66
Doc. No
Model
Apparatus
Scale
Page No
1SDH000909R0001
12.3.3.1. L Protection
The L protection cannot be disabled.
On unit PR122/VF it is possible to select current threshold (I
1
) and time (t
1
), and to define the preferred tripping time (t
trip
).
Setting
Range Value
Description
Threshold I
1
0.4In...1In (step 0.01In)
Set fault threshold of the primary current
Time t
1
3s...102s (step 3s)
Set t
trip
of L protection
The unit applies an inversion time expression to calculate t
trip
.
The expression considers the primary fault current (I
f
), and the protection parameters (I
1
and t
1
):
Condition
t
trip
(s)
Example
I
f
≤
10In
t
1
0,1178
----------------
If
( )
2
If
( )
2
I
1
( )
2
–
-------------------------------
ln
×
I
1
= 0.8 x In; t
1
= 12s
I
f
= 1.5 x I1 (1.2 x In)
ttrip
12
0,1178
----------------
1,2
(
)
2
1,2
(
)
2
0,8
(
)
2
–
-------------------------------------
ln
×
101,87 0,588
×
60
s
=
=
=
I
f
> 10In
0.5
I
1
= 0.8 x In; t
1
= 12s
I
f
= 15 x I
1
(12 x In)
t
trip
=
0.5 s
WARNING: L Threshold has activated in the range 1.05...1.2 of the setting.
The minimum trip time is 0.5s. See trip curves for further details.
12.3.3.2. I Protection
The I protection is enabled/disabled on protection menu.
On unit PR122/VF it is possible to select current threshold (I
3
), and there is the possibility to set Start-up parameters.
Setting
Range Value
Description
Enable
ENABLE/DISABLE
Determines the presence or absence of the protection.
Threshold I
3
1.5In...10In (step 0.1In)
Determines the fault threshold of the primary current
Startup Enable
ENABLE/DISABLE
Determines the presence/absence of the Start-up function.
Startup threshold
1.5In...10In (step 0.1In)
Determines the start-up current threshold
Startup time
0.1s...30s (step 0.01s)
Determines the activation duration of the start-up threshold
While the I protection is turned OFF, only the L protection will operate for all the fault current range.
While the I protection is turned ON, the unit will trip by I protection with I
f
> I
3
. The t
trip
for I protection is
≤
60ms.
The Start-up function is enabled/disabled from the I protection menu.
The Start-up function enables the protection threshold I
3
to be changed
during a t
s
time interval, starting from the passing of almost 1 of the phase
currents over the “Start-up activation threshold”.
The “Start-up activation threshold” is an adjustable parameter for values
within the range 0.1...10In, with steps of 0.1In.
The parameter is available only by external communication, using the
module PR120/D-M ,or the external unit BT030-USB or Ekip T&P with
ABB Software Ekip Connect .
A new start is possible after the current has dropped below this threshold.
WARNING: On the display menu, the I protection settings (threshold and Startup parameters) are available to user
only with protection enabled.
About Startup function, all settings (threshold and time) are available to user only with function enabled.
12.3.3.3. T Protection
Inside unit PR122/VF, there is a temperarature sensor that monitors the temperature of the unit.
The sensor enables the signalling of any abnormal temperature conditions, which could cause temporary or continuous malfunctions
of the unit or the electronic components.
On unit PR122/VF it is possible to Enable the Trip in case of T alarm.
Setting
Range Value
Description
Trip Enable
ENABLE/DISABLE
Set the possibility of CB Opening in the case of T alarm
I
t
Start-Up Threshold I2
ts
Threshold I2
Activation of Start-Up
Threshold Start-Up activation
