ABB ACS550-01 - Page 136

136 ACS550 User’s Manual
Start-Up
8104 REFERENCE STEP 2
Sets a percentage value that is added to the process reference.
• Applies only when at least two auxiliary (constant speed) motors are running.
• See parameter 8103 REFERENCE STEP1.
8105 REFERENCE STEP 3
Sets a percentage value that is added to the process reference.
• Applies only when at least three auxiliary (constant speed) motors are running.
• See parameter 8103 REFERENCE STEP1.
8109 START FREQ 1
Sets the frequency limit used to start the first auxiliary motor. The first auxiliary motor starts if:
• No auxiliary motors are running.
• ACS550 output frequency exceeds the limit:
8109 + 1 Hz.
• Output frequency stays above a relaxed limit
(8109 - 1 Hz) for at least the time: 8115 AUX MOT START D.
After the first auxiliary motor starts:
• Output frequency decreases by the value =
(8109 START FREQ 1) - (8112 LOW FREQ 1).
• In effect, the output of the speed regulated motor drops to
compensate for the input from the auxiliary motor.
See figure, where:
• A = (8109 START FREQ 1) - (8112 LOW FREQ 1)
• B = Output frequency increase during the start delay.
• C = Diagram showing auxiliary motor’s run status as frequency
increases (1 = On).
Note! 8109 START FREQ 1 value must be between:
• 8112 LOW FREQ 1
• (2008 MAXIMUM FREQ) -1.
8110 START FREQ 2
Sets the frequency limit used to start the second auxiliary motor.
• See 8109 START FREQ 1 for a complete description of the operation.
The second auxiliary motor starts if:
• One auxiliary motor is running.
• ACS550 output frequency exceeds the limit: 8110 + 1.
• Output frequency stays above the relaxed limit (8110 - 1 Hz) for at least the time: 8115 AUX MOT START D.
8111 START FREQ 3
Sets the frequency limit used to start the third auxiliary motor.
• See 8109 START FREQ 1 for a complete description of the operation.
The third auxiliary motor starts if:
• Two auxiliary motors are running.
• ACS550 output frequency exceeds the limit: 8111 + 1 Hz.
• Output frequency stays above the relaxed limit (8111 - 1 Hz) for at least the time: 8115 AUX MOT START D.
Code Description
t
P 8115
(P 8109)+1
P 8112
AB
f (Hz)
f
MAX
f
MIN
1
0
t
C
P 8109
A