ABB DriveIT ACH550-UH - Page 139

ACH550-UH User’s Manual 139
Start-Up
5 = DI5 – Enables the Interlock function, and assigns a digital input (starting with DI5) to the interlock signal for each
PFA relay. These assignments are defined in the following table and depend on:
• The number of PFA relays (number of parameters 1401…1403 and 1410…1412) with value = 31 (
PFA).
• The Autochange function status (disabled if 8118
AUTOCHNG INTERV = 0, and otherwise enabled).
6 = DI6 – Enables the Interlock function, and assigns digital input DI6 to the interlock signal for the speed regulated
motor.
• Requires 8118 AUTOCHNG INTERV = 0.
8121 REG BYPASS CTRL 0…1 1 0
Selects Regulator by-pass control. When enabled,
Regulator by-pass control provides a simple control
mechanism without a PID regulator.
• Use Regulator by-pass control only in special
applications.
0 = NO – Disables Regulator by-pass control. The drive
uses the normal PFA reference: 1106
REF2 SELECT.
1 =
YES – Enables Regulator by-pass control.
• The process PID regulator is bypassed.
Actual value of PID is used as the PFA reference
(input). Normally
EXT REF2 is used as the PFA
reference.
• The drive uses the feedback signal defined by
4014
FBK SEL (or 4114) for the PFA frequency
reference.
• The figure shows the relation between the control
signal 4014
FBK SEL (OR 4114) and the speed
regulated motor’s frequency in a three-motor
system.
Group 81: PFA
Code Description Range Resolution Default S
No. PFA
Relays
Autochange Disabled
(P 8118)
Autochange Enabled
(P 8118)
0
DI1…DI4: Free
DI5: Speed Reg Motor
DI6: Free
Not allowed
1 DI1…DI4: Free
DI5: Speed Reg Motor
DI6: First PFA Relay
DI1…DI4: Free
DI5: First PFA Relay
DI6: Free
2 Not allowed DI1…DI4: Free
DI5: First PFA Relay
DI6: Second PFA Relay
3…6 Not allowed Not allowed
No. PFA
Relays
Autochange Disabled Autochange Enabled
0
DI1…DI5: Free
DI6: Speed Reg Motor
Not allowed
1 Not allowed
DI1…DI5: Free
DI6: First PFA Relay
2…6 Not allowed Not allowed
P 4014
f
MAX
P 8110
P 8109
P 8113
P 8112
A = No auxiliary motors running
B = One auxiliary motor running
C = Two auxiliary motors running
A
f
MIN
B
C
(%)
f
OUT