PD6600 Series Loop-Powered Process Meters
Instruction Manual
36
Pump Alternation Example
The following is an example application where the re-
lays are programmed for pump alternation.
On & Off Point Programming
Relay
On Point
Off Point Function
1
7000
1000 Controls backup pump
2
6000
1000 Controls main pump
The following graphics provide a visual representation
of a typical pump alternation application:
Note: Open Collectors can be used for high and low
alarm indication.
Timer (
TIMER
)
The timer output may be set to generate the timed
pulse only once (
ONESHOT
) or continuously (
CONT
).
The timer output produces a constant width pulse at a
constant frequency, if set as continuous timer.
Program the
Off Delay
(
OFF.DLAY
) from 1 second to
99 hours 59 minutes and 59 seconds. This is the time
it takes from selecting
START
to turning on the output
and for how long the output is off in continuous mode.
Program the
On Time
(
ONTIME
) for the active low
pulse from 1 second to 99 hours 59 minutes and 59
seconds (pulse width). This is the period of time for
which the output will remain on.
Select
Start
(
START
) to begin outputting the constant
timed pulse. Select
Stop
(
STOP
) to end outputting the
constant timed pulse. Function keys or the digital
input may be assigned to start and stop timer
functions (see the
USER
menu in
Advanced
).
6245
GAL
!
6245
GAL
!
7153
GAL
!
995
GAL
Relay #2 turns the main pump on at 6000 gallons and turns it o
ff at
1000 gallons.
With the PumpAlternation feature activated, the next time the level
reaches 6000 gallons, relay #1 transfers and starts the backup
pump.
If the backup pump is not able to keep up, and the level reaches
7000 gallons, relay #2 transf ers and starts the main pump as well.
Once the level has dropped below the reset points, both relays will
turn off .
OUT 1
TIMER
TIMER
OFF.DLAY
TIMER
ON TIME
TIMER
MODE
TIMER
START
MODE
CONT
MODE
ONE.SHOT
H.MM.SS
00.01.00
H.MM.SS
00.00.01
TIMER
STOP
