Rockwell Automation 1766-L32 Pump Station Controller Quick Start - Manual (Page 15)

Publication IASIMP-QS037A-EN-P - May 2013 13
Chapter 1
Because this is a backup operation likely due to a failure, the pumps do not
alternate.
Setup Examples
Example 1: In a pump
down application. Floats
are being used as backup.
On the Pump Sequence
Setup screen, the Primary
selection for all pumps is
set to Alternate, and the
Secondary selections are
set to Lag1. And on the
Backup Pump Selection
screen, lead, lag1 and lag2
pumps are all allowed to
run as backup. As the level rises and activates the Lead Start float. The lead
pump (because all are set for alternate, it could be any of the four pumps)
starts. Let’s say that the Delay Between Pump Starts (see graphic above) is
set for 60 sec. If the Pumps Stop float does not clear in this time, all of the
pumps assigned to Lag1 as Secondary will start (in this case all of them). If a
pump was set to Lag2 as the Secondary selection, it will start 60 sec. after the
Lag1 pump(s) start. If all of the pumps are set to Lag2 as Secondary, then no
pumps will start during the first 60 sec. (Lag1 time). The sequence is: lead
pump --- delay --- lag1 pump(s) --- delay --- lag2 pump(s). Once a pump starts,
it will continue to run until the Pumps Stop float clears.
Example 2: Same setup as
above except the
Secondary selections are
now as shown. Let’s say that
pump 2 is the lead pump.
Lead Start float is activated.
Pump 2 starts --- 60 sec.
time delay --- pump 1 (lag1) starts --- 60 sec. time delay --- pump 3 (lag2) starts.
Because pump 4 is set to Not Used it does not run.
Example 3: The setup is as
shown, however now the
Lag1 pump is not allowed
to run in backup. Again,
let’s say that pump 2 is the
lead pump. Lead Start float
is activated. Pump 2 starts
--- 60 sec. time delay --- and
although pumps 1 and 3 are
both set for lag1, they do no