BASIC SETTINGS
Setpoint Pressure
The Setpoint Pressure is the target pressure to be maintained at the pump discharge. It cannot exceed the
maximum range of the pressure transmitter.
Sleep Frequency
The Sleep Frequency setting should be set to the frequency at which the lead pump no longer builds pressure
when operating at or near the Setpoint Pressure. The lead VFD will enter the sleep mode when the output
frequency of the lead VFD drops below the Sleep Frequency for a period of time (Sleep Time). The sleep
function is suspended while the lag VFD is in operation.
Sleep Delay Time
Set the Sleep Delay Time to the amount of time that the lead VFD will wait before entering sleep mode after
the output frequency drops below the Sleep Frequency. Note: If the system cycles on and off too frequently,
try the following: increase the Sleep Delay Time, lower the Sleep Frequency, or increase the Lead Pump Start
Differential Pressure. A combination of changes of all three settings may be necessary. If the lead VFD does
not enter sleep mode when there is no flow of water in the system, the Sleep Frequency must be increased.
Minimum Frequency
The Minimum Frequency should be set to the minimum output frequency that the pumps should be allowed to
run. Contact your pump manufacturer to obtain the pump safe operation ranges.
Maximum Frequency
The Maximum Frequency should be set to the maximum output frequency that the pumps should be allowed
to run. Warning! Running above the motor nameplate frequency (50Hz or 60Hz) may cause damage to the
pump. Contact your pump and motor manufacturer for operation above the rated frequency on the nameplate.
Lead Pump Start Differential Pressure
The Lead Pump Start Differential Pressure is the amount of pressure drop from the Setpoint Pressure, at
which the lead VFD will wake from sleep and run to maintain the system pressure. The lead pump will start if
the pressure drops below the Setpoint Pressure less the Lead Pump Start Differential Pressure. Example: If
the Setpoint Pressure is 40 PSI and the Lead Pump Start Differential Pressure is -5 PSI, the lead pump will
start when the pressure drops below 35 PSI.
Lag Pump Start Differential Pressure
The Lag Pump Start Differential Pressure is the amount of pressure drop from Setpoint Pressure, while the
lead VFD is running full speed before a lag VFD is started. The lag VFD speed is controlled to maintain
pressure while in operation. The lead VFD will not be allowed to enter sleep mode while a lag VFD is running.
Lag Pump Stop Differential Pressure
The Lag Pump Stop Differential Pressure is the amount of pressure over the Setpoint Pressure before the lag
VFD is stopped.
Alternation
The Alternation setting can be adjusted to alternate the operation of Pump 1, 2 and 3 or to keep Pump 1, 2 or
3 as lead pump.
Alternation Time
The Alternation Time is the total accumulated run time of the current lead VFD, before the lead operation is
passed to the next available VFD in the sequence. Alternation Time is intended to even out the wear of the
pumps by transferring the lead operation after a set period of run time. Set to "0" to disable alternation.
Low Pressure Alarm
The Low Pressure Alarm is used to notify the user and stop the system if system pressure is unable to be
maintained at an allowable pressure. The Low Pressure Alarm can be set up to automatically reset after the
Low Pressure Alarm Reset Delay Time, or to require a manual reset by the user.
• Low Pressure Alarm
The Low Pressure Alarm setting should be set to the pressure below which the controller activates the Low
Pressure Alarm after the Low Pressure Alarm Delay Time.
• Low Pressure Alarm Delay Time
The Low Pressure Alarm Delay Time setting should be set to the amount of time that the system is below
the Low Pressure Alarm pressure, before the Low Pressure Alarm flag is set and pump operations are
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VFDC-3000 Controller User Manual