Nova-Tech Pulsatron Plus Series T7 - Manual (Page 9)

9
5.3.2 Stroke Length Adjustment
Stroke length can be controlled within 0 to 100% of the diaphragm displacement. It
should be controlled within 20 to 100% for practical use.
Stroke length can be set by means of the stroke length adjusting knob while the
pump is in operation. Do not turn the knob while the pump is stopped.
5.3.3 Controlling Procedure
Proper set points for stoke length and stroke frequency should be determined after
consideration of the pump and characteristics of the fluid. The following procedure is
recommended from the viewpoint of pump performance. Note: The closer the
stroke length is to 100%, the better the pump performance will be.
Set the stroke length to 100% then adjust the stroke frequency for coarse capacity
control.
Measure the capacity.
When the measured capacity is less than the required value, increase the stroke
frequency and measure the capacity again.
Then, adjust the stroke length for fine capacity control.
Finally, measure the capacity and make sure that the required value is obtained.
Example Selected Model = LPD4
Set Stroke Length = 100%
Set Stroke Rate = 100%
Output Capacity = 21 gallons per day (GPD)*
(Rated Pressure)
Desired Flow = 15 GPD
Adjust Stroke Rate to 80%
Output Capacity = 0.80 x 21 = 16.8 GPD*
Stroke Length Setting = 15 x 100 = 90% approximate
16.8
Thus to obtain the desired flow, stroke length is set at 90% and stroke rate is set at 80% i.e. output capacity = 0.90 x 0.80
x 21 = 15.12 GPD*
*IMPORTANT!
Check these values by measurement. Output capacity is higher when feeding against less than rated pressure
5.4 Control Panel Symbols
The pumps come with universally accepted symbols which is provided in appendix A, page 14.
5.5 Operation By External Input Signals (Options):
The pump can be controlled by three types of input signals. All are fully isolated from AC input and from earth ground.
The input socket connections are located at the bottom of the control panel face and the signal cords are provided with
the pump. Remove rubber plugs to access plug sockets.
5.5.1 Stop Function (E+, A+, C+ and C only)
Operation of the pump can be stopped by an external signal input. When the external signal is input to the terminal
marked
which is provided at the bottom of the control panel, the lamp (red) lights up and operation of the pump is
stopped. The stop function overrides both manual settings and external input.
Operation of more than one pump from the same contact closure will damage the pump circuits.
When such operation is required, the pump circuits must be electrically isolated from one another by means of a
multi-contact control relay or similar means.
The input signal must be in the form of closure of a mechanical relay or other mechanical switching device, or solid-state
relay or other solid-state switching device. Voltage signals are prohibited. The switching resistance of either mechanical
or solid-state devices must be 100 ohms or below when ON and 1 megohm or above when OFF. If any type of solid-state
device is employed, it must be installed with the proper polarity, if required for the device; and leakage current must not
exceed 200 microamperes to prevent false triggering in the OFF state.
The stop function is commonly used in conjunction with a tank float switch. The float switch contacts are normally open
but when the tank level falls past a certain point the contacts close and the pump stops.