For a two and three pump system the start distribution is 1:1 during normal inflow
situations. During high inflow situations the start distribution is 5:5:2 for a three pump
system, but remains 1:1 for a two pump system.
[m]
P2 low
P1
P2 high
P3 high
P3 low
Stop level
24 cm
6 cm
WS008407C
Pump block
Pump block is used to block backup pumps to run at the same time as the main pump. If
the pump or pumps that have been installed for redundancy purposes and they must not
run simultaneously due to electrical or mechanical issues, then block the backup pump.
Even when the inflow is higher than the capacity of a single pump, the function blocks
other pumps from operating. The pumps alternate over time. To activate Pump block,
connect pump running output, terminal 11 of one drive to the pump block input, terminal
2 of the other drive and set the P2-13:Analog output 2 function parameter to 3: Motor
speed > 0, default.
Ext Block
+24V
Alarm reset High
level
in
Gnd
T2 in
Lvl signal
out
Gnd Lvl signal
in
Active pump Inhibit in Inhibit out
+10V
1 2 3 4 5
6 7 8 9
10 11 12 13
Control Terminal Unit 1
Relay 1 NO
Relay 1 COM
Relay 1 NO
Relay 2 COM
Relay 2 NO
14 15 16 17 18
Relay Terminal Unit 1
Ext block
+24V
Alarm reset High
level in
Gnd
T2 in
Lvl signal
out
Gnd Lvl signal
in
Active pump Inhibit
in
Inhibit
out
+10 v
1 2 3 4 5 6
7 8 9 10 11 12 13
Control Terminal Unit 2
Relay 1 NO
Relay 1 COM
Relay NC Relay 2 COM
Relay NO
14 15 16 17 18
Relay Terminal Unit 2
WS008441C
Pump block on a three pump system
Since relay 1 and 2 are used for alternation or Pump block, extra I/O extension modules
are required to get alarms and other run time information as relay signals for this
application.
1. Install the three pump system according to the instructions in
(page 28).
2. Connect a lead between control terminal 1 and relay terminals 14 and 17 on all three
drives.
3. Connect a lead between control terminal 2 on drive 1 to relay terminal 18 on drive 2
and 3.
4. Connect a lead between control terminal 2 on drive 2 to relay terminal 15 on drive 1
and 3.
5. Connect a lead between control terminal 2 on drive 3 to relay terminal 18 on drive 1
and relay terminal 15 on drive 2.
6. Configure relay output 1 by changing parameter P6-19:Relay output 1 from 7: A-
Alarm to 9: Pump running on all three drives.
System Setup and Operation
SRC 311 - SmartRun
™
Installation, Operation, and Maintenance Manual
39
