e.g. relays 1, 2 and 3 control three pumps by service ratio. It is required that
pump 1 operate 60% of the time, pump 2 operate 10% of the time and
pump 3 operate 30%of the time.
» set the relay function : P-8, 11, 14 = dE : A9
» set the relay setpoints : P-9/10, 12/13, 15/16
» set the P-24, 25, 26 ratios : A-24 = 60
A-25 = 10
A-26 = 30
Relays assigned to pump control operation are software set that no two pumps can
start up within 10 seconds of each other, a power failure or return to the run mode.
When in the program mode, pump relays will be held de-energized (OFF). In the
event of a loss of echo condition, the pump relays can be individually
programmed to be:
» de-energized (dE)
» energized (En)
» hold (Ho)
when the fail-safe timer P-75 expires. Refer to Applications/Relays.
In applications where flooding is possible, a submersible transducer should be used.
The submersible transducer’s air cavity insures that a high level reading will be
maintained rather than a loss of echo condition when the liquid level reaches the
transducer.
When using a submersible transducer, set P-23.
When relays are assigned a pump function, parameters P-24 through P-28 are used
to log the respective service hours and number of pump starts for pump relays
1 - 5. These parameters may also be viewed while in the run mode by pressing the
appropriate programmer keys. The initial pressing of the key causes the display to
show the service hours. Holding the key in for at least five seconds causes the
number of starts to be displayed. Each register may be reset to 0 by pressing "CLR"
and then "ENTER" or preset by entering a particular value.
The preset value is immediately stored in memory, however subsequent values are
only stored every 4 hours. Thus, after a power failure, the registers will display the
last value stored. The registers will automatically reset to 0.000 after reaching a value
of 9,999.
PL-443 6 – 6
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