Chapter 2
2.1 Description of Functions
LCD Display
The LCD Display is a user friendly operator interface with 240 x 64 pixels resolution; it allows the user to quickly view the
system status and log.
Multiple Pumps Parallel Operation
The controller is able to control up to four (4) pumps utilizing all VFD’s, or one VFD with up to 3 ATL (across the line)
starters for the lag pumps.
Lead/Lag Operation
A fully automatic lead/lag operation based on the variation of the system discharge flow allows you to significantly reduce
your energy cost and consistently maintain the system pressure. While the lead pump is operating, the system will
sequentially start and stop lag pump(s) based on variation of the system pressure.
Across The Line (ATL) Pump Operation
When enabled and utilized, this function allows for multiple pumps to be controlled in a true PID pressure control system,
while only needing one VFD. When the output of the lead pump (VFD) is at 100%, the controller changes that pump over
to direct (ATL) operation and switches on the first lag pump using the VFD. In the same way, lag pump 2 and 3 can be
added as needed for heavy flow conditions. The pump being controlled by the VFD will always be varying its speed as
needed to maintain the set pressure.
Automatic Re-Start
Should the system shutdown by a sudden power loss, it will automatically restart when the power is restored. No manual
reset is required. The system automatically returns to the running condition programmed and stored in the system memory.
Lead Pump Alternation
When selected as set time based, the alternation will occur when the total operating time of the lead pump reaches to
the alternation time; the system automatically selects the next pump in sequence to be the lead pump. This function is
designed to reduce the system life cycle cost. The system make all pump operate for equal period of time as to prevent
the over-use of a particular pump resulting in high parts wear of the pump. The alternation may also be cycle based
rather than time based.
Faulty Pump(s) Skip Function
The system automatically skips any pump sending a fault signal to the controller, and immediately changes the operating
sequence to the functioning pumps. The faulty VFD/Pump will continue to report its fault until maintenance personnel can
diagnose and repair the fault condition. A fault can be any of the following: VFD fault, starter overload trip (when using
starters) or HAND/OFF/AUTP (HOA) selector switch is not in the AUTO position.
Dry Run Prevention
The system automatically stops the running pump(s) upon the detecting a Low pressure signal (Low Water). This
function prevents the pump(s) from dry running that may result in damage to the pump(s).
Program
Used to program the set pressure to change based on a time/day/month basis.
Dual Set Pressures
An additional SET PRESSURE is available in the PRESSURE menu and can become the active set pressure by
activating input 018 on CN8. This function can be useful for systems with large fluctuations in suction pressure or large
variations in demand flow.
Alarm Display and Logging
The system displays alarm conditions on the LCD monitor, and records the condition in a log that is date and timed
stamped.
Operating Data Display and Storage
The semi-permanent operating data recording and storage for each pump allows efficient pump maintenance.
SJE®
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VFDC-4100 Controller User Manual
