Table of Contents
Advertisement
current lead pump is displayed
on the right side of the top line of
the display. When the lead pump
starts the liquid level should begin
to fall as liquid is pumped out of
the well. When the level falls to
the lead pump off setpoint then
the lead pump will be stopped
and the alternator sequenced if
it is on. If the level continues to
rise it will reach the lag pump on
setpoint and the lag pump will be
called. If the level then falls to the
lag pump off setpoint then the lag
pump will be turned off. The lag
pump will not be called if the total
number of pumps setpoint is 1.
If the lead and lag pump running
do not cause the level to fall then
the third pump will be called
when the level reaches the lag2
on setpoint and if three pumps are
selected for the maximum number
of pumps. If the level continues
to rise then it will reach the high
alarm setpoint and set a high
alarm condition. The high alarm
light and relay will be activated.
If the horn is enabled then it too
will be activated until the alarm
condition clears or until the mute
button is depressed.
Single Float
Backup
A single float backup system is
provided in pump down mode
only.
It can be useful if the
primary level sensor fails.
single normally open float switch
is connected to the float input
and suspended in the well at a
point above the normal operating
levels of the system. In this way
the float will be submerged only
if level rises above that required
to call on all available pumps.
The backup system is enabled by
setting a backup time (in seconds)
in the backup time setpoint of the
configuration menu. If this time
4
is zero then the backup system
is disabled. If the high float is
activated, and backup is enabled,
and the pumps are not already
calling for all available pumps
then the backup mode is initiated.
The float light on the front panel
is turned on and the lead pump is
called to run. At the same time
two timers are started, one for 30
sec. and one for 60 sec. If the
high float opens (comes out of the
liquid) then these two timers are
cleared and no further pumps will
be called. The lead pump will
remain on for the period of time
set in the backup time setpoint.
If the 30 second timer expires
before the high float opens then
the lag pump will be called if
there are at least 2 pumps. If the
60 second timer expires before the
high float opens then the second
lag pump will be called if there
are three pumps. All pumps will
be sequentially turned off after
the high float has been open for a
period of time equal to the backup
timer setpoint.
on the front panel will remain on
until cleared by the reset/mute
button on the panel or the external
reset/mute button.
Pump Sequence
Timers
In both pump up and pump down
modes there are two timers which
A
prevent more than one pump
from turning on or off at the
same time. These timers prevent
excess power loads when pumps
are turning on and some hydraulic
problems (water hammer) when
pumps are being turned off.
Time At
Setpoint
The NOVUS 4000 has a feature
that prevents any pumps from
being turned on or off until a
setpoint condition has been
satisfied for a minimum time.
This minimum time is the TIME
AT SP setpoint in the setup menu
and can be set from 0 to 31
seconds. As an example, assume
this setpoint is set for 8 seconds,
and we have a pump down system
(lift station).
level in the tank must exceed the
lead on setpoint continuously for
8 seconds before the lead pump
will be called. There is not much
need for this in most lift stations
as the level changes slowly, but
this feature can be very useful in
water pressure (pump up) systems
where the pressure may swing
wildly for several seconds after a
pump is turned off or on. If this
time is set longer than the pressure
The float light
takes to settle, then no further
pump calls will happen until the
new pressure has stabilized.
Fail To
Start Test
The NOVUS 4000 has an optional
fail to start test. This optional test
is controlled by the START TEST
time in the setup menu. If this time
is zero then this test is disabled. If
the start test is enabled then the
AUX/DIS inputs for each pump
must be connected through a dry
contact to ground. These contacts
must close and short the AUX/
DIS input to ground when the
pump is running. The auxiliary
contact on the starter or a switch
on the check valve arm can be
used. If the start test is disabled
(time=0) then these inputs are
pump disable inputs.
Then, the water
Advertisement
Table of Contents
