Freeze Prevention
When this function is enabled the lead pump will automatically start at the VFD minimum output for 30 seconds and then
shift to the next pump when the temperature is under 32 deg. This will occur when all pumps are stopped for more than
30 seconds at the same time.
Idle Prevention
If the lead pump does not run for the set time, corrosion of some parts may occur. In order to prevent this, the system
will automatically run the lead pump at the minimum operating speed for 60 seconds and then starts the next pump in
sequence. The same process will be repeated if the succeeding lead pump does not run during the set time.
Password
If the password function is enabled, a pop-up window will appear when you press the MENU button. You must enter your
password to access the setup screens. This is to prevent access to the input values by an unauthorized person. You can
change or disable the user password if you wish, however once enabled you must remember the value to gain access to
the setup menu.
Communication
It is possible to monitor the system remotely when connected via the RS-485 port. See page 24 for details.
PID Control
The microprocessor based controller is programmed to perform adjustable Proportional, Integral and Derivative control to
provide consistent and reliable pressure control.
LCD Screen Saver
The back light of the LCD display is programmed to automatically fade out if the keypad is not used for a set time. This
function allows for maximum life span of the LCD monitor. This function can be disabled if desired.
Jockey Pump Function
The role of the Jockey pump is to maintain constant pressure during low flow conditions. When utilized, the jockey pump
is typically much smaller than the main pumps and is well suited to handle variations in flow at a low flow rate. When flow
demand exceeds the capacity of the Jockey pump and the main pumps are called to run, the Jockey will turn off after a
programmable delay time, minimizing wear on the small pump.
Pre-Charge Function
In systems that drain out when not running, the pre-charge function allows for filling the piping system without causing
damage. This function allows for the lead pump to run at a low preset speed for a preset time prior to switching over to
full automatic operation. This greatly reduces water hammer to the piping system.
SJE-Rhombus VFDC-4100 Controller User Manual
5
2.2 Security
The security system is designed to prevent access by unauthorized persons to the setup menu without entering a user
password. If this function is turned on in the protect menu you will be required to enter the password to gain access to
the setup screens. When you press the [Menu] button, the password pop-up window will appear. You must enter your
user password to access the setup menu screens.
Set the password in the password function under the protect menu item by using the up/down & right/left key and press
the enter button. The password must consist of 4 numbers.
After entering the password, and exiting the setup menu, access to the setup screens will be locked. The password will
then need to be re-entered to access the setup screens.
