ABB DCS 400 - Alarm Trip Threshold; Monitoring the Mains Voltage

II K 4-28
Overview of Software
5% above this tripping threshold, an alarm signal
A02-Mains Voltage Low will be generated. The
alarm range shifts when the Net Underv Trip (1.10)
parameter is altered.
The alarm does not impair the drive in terms of its
function.
This message indicates that
• in regenerative mode for decelerating in the ma-
chine's rated operating point, the ratio between
minas voltage and motor voltage is approaching
the critical range (1...5 % before disconnection on
fault). In the alarm range, however, deceleration
mode is still possible and permissible. If the mains
voltage continues to fall, a disconnection on fault
must be anticipated, since otherwise there will be
a risk of shoot-through.
• in motoring mode, the ration between mains
voltage and motor voltage has dropped into the
alarm range, and a disconnection on fault is immi-
nent. In the alarm range, however, the drive's
function is still assured. Any further drop in the
mains voltage will trigger a disconnection on fault.
Alarm trip threshold:
A02
Level
= F09
Trip Level
+ 5% (fix)
Monitoring the Mains Voltage:
e.g. Mains Supply Voltage = 400 V
Application = 4-Q
Armature Voltage Nominal = 420 V
… with default settings:
Net Underv Trip (1.10) = 0%
2-Q - application
U
net
(V)
F09-Fault
level
(V)
A02-Alarm
level
(V)
U
DC
(V)
U
DC max
(V)
230
207 217 270
285
380
353 370 460
471
400
360 378 470
496
415
376 395 490
514
440
399 419 520
545
460
414 435 540
570
480
437 459 570
595
500
460 483 600
619
4-Q - application
U
net
(V)
F09-Fault
level
(V)
A02-Alarm
level
(V)
U
DC
(V)
U
DC max
(V)
230
205 216 240
255
380
342 359 400
422
400
359 377 420
444
415
368 386 430
461
440
393 413 460
489
460
411 431 480
511
480
428 449 500
533
500
445 467 520
555
Fault and Alarm Level for specified motor voltage
(U
DC
) with:
Net Underv Trip (1.10) = 0%
Uarm (1.02)
= 420V
Unet
act
(1.07) = 400V
Unet
min
= 359V
F09-Mains Undervoltage
A02-Mains Voltage Low
A02
Level
= 377V
Alarm range
(1.10) = 0%
A02
Level = F09 Trip Level + 5% (fix)
F09
Trip Level = Unet min + Net Underv Trip (1.10)
Uarm (1.02)
= 420V
Unet
act (1.07)
= 400V
Unet
min
= 359V
= F09
Trip
if Net Underv Trip (1.10) = 0% (default)
then 359V (Unet min) is the trip level for F09.
For right operation Unet
act
has to be greater
than 359V.
F09-Mains
Undervoltage
acc. to formula
Unet
min = Uarm / (1,35 x cos
α
)
Unet
min
= 359V
A02-Mains Voltage Low
(5% (fix) above Unet
min
)
A02
Level
= 377V
permitted
operating range
for Unet
U
DCmax
= (U
net
*1.35 * cos a) - 5% Alarm level
(Mains voltage deviation is not considered.)