ABB UNITROL 1020 - Limiters

 Chapter 6 - Operation
UNITROL 1020 User Manual 3BHS335648 E82 105
6.3.9 Limiters
A limiter triggers the SCP’s limiter response, which causes the panel’s green LED to flash
and a limiter message will be displayed on the screen every few seconds.
Operating
Resulting Display
LIMITERS in REMOTE mode
The display periodically switches from the indication view
to the limiter view and back to the indication view.
It is still possible to navigate in the SETPNT or MENU, but
the limiter is always displayed for a short time.
The blinking display can be disabled by changing the
panel to local control. Active limiters can be seen in the
parameter/signal group “Limiter status” (Group 05).
Example: Limiter 12 = 4 + 8 (see the table below)
The limiters “Max Ie” and “V/Hz” are blinking
0.0 V UN
AUTO Grid
0.0 kV UM
100.0% E
REM L
SETPNT
12:45
MENU
LIMITER 12
Limiter Active
LIMITER
REM L
12:50
The V/Hz and setpoint limiters are added to the other limiter.
E.g. Limiter 12 display means that Max Ie and the V/Hz limiter are active.
The following limiter numbers can be monitored from the panel:
Limiter No.
Description
Short Term
0
None
1
Minimum Excitation Current Limiter active
Min Ie
2
Minimum Machine Voltage Limiter active
Min UM
3
Minimum Iq Limiter active (PQ-Limiter)
Min Iq
4
Maximum Excitation Current Limiter active
Max Ie
5
Maximum Machine Voltage Limiter active
Max UM
6
Reserved
7
Maximum Machine Current Limiter active
Max IM
+8
V/Hz Limiter active
+16
Minimum Setpoint reached
+32
Maximum Setpoint reached