ABB ACS550-01 - Page 137

ACS550 User’s Manual 137
Start-Up
8112 LOW FREQ 1
Sets the frequency limit used to stop the first auxiliary motor. The first auxiliary motor stops if:
• The first auxiliary motor is running alone.
• ACS550 output frequency drops below the limit:
8112 - 1.
• Output frequency stays below the relaxed limit
(8112 + 1 Hz) for at least the time: 8116 AUX MOT STOP D.
After the first auxiliary motor stops:
• Output frequency increases by the value =
(8109 START FREQ 1) - (8112 LOW FREQ 1).
• In effect, the output of the speed regulated motor increases to
compensate for the loss of the auxiliary motor.
See figure, where:
• A = (8109 START FREQ 1) - (8112 LOW FREQ 1)
• B = Output frequency decrease during the stop delay.
• C = Diagram showing auxiliary motor’s run status as frequency
decreases (1 = On).
• Grey path = Shows hysteresis – if time is reversed, the path
backwards is not the same. For details on the path for starting,
see the diagram at 8109 START FREQ 1.
Note! Low Frequency 1 value must be between:
• (2007 MINIMUM FREQ) +1.
• 8109 START FREQ 1
8113 LOW FREQ 2
Sets the frequency limit used to stop the second auxiliary motor.
• See 8112 LOW FREQ 1 for a complete description of the operation.
The second auxiliary motor stops if:
• Two auxiliary motors are running.
• ACS550 output frequency drops below the limit: 8113 - 1.
• Output frequency stays below the relaxed limit (8113 + 1 Hz) for at least the time: 8116 AUX MOT STOP D.
8114 LOW FREQ 3
Sets the frequency limit used to stop the third auxiliary motor.
• See 8112 LOW FREQ 1 for a complete description of the operation.
The third auxiliary motor stops if:
• Three auxiliary motors are running.
• ACS550 output frequency drops below the limit: 8114 - 1.
• Output frequency stays below the relaxed limit (8114 + 1 Hz) for at least the time: 8116 AUX MOT STOP D.
8115 AUX MOT START D
Sets the Start Delay for the auxiliary motors.
• The output frequency must remain above the start frequency limit (parameter 8109, 8110, or 8111) for this time
period before the auxiliary motor starts.
• See 8109 START FREQ 1 for a complete description of the operation.
8116 AUX MOT STOP D.
Sets the Stop Delay for the auxiliary motors.
• The output frequency must remain below the low frequency limit (parameter 8112, 8113, or 8114) for this time
period before the auxiliary motor stops.
• See 8112 LOW FREQ 1 for a complete description of the operation.
Code Description
t
P 8116
(P 8112)-1
B
f (Hz)
f
MAX
f
MIN
t
1
0
C
P 8112
P 8109
A
A