Elkhart Brass 2900E Series - Manual (Page 5)

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II. SYSTEM DESCRIPTION:
The 2900E series electrically actuated valve line includes a complete range of ball valve
sizes including 1-1/2”, 2”, 2-1/2”, 3”, and 4”, and butterfly valves in 2”, 3”, 4”, 5”, and
6” sizes. The valve opening and closing actions are controlled by a bronze worm gear
case driven by a 12 volt DC gear motor. One size gear motor and gear case assembly is
used on the 1-1/2”, 2”, and 2-1/2” ball valves and a larger gear motor and gear case are
used on the 3” and 4” ball valves and all sizes of butterfly valves.
Each motor-driven valve is coupled to a combined valve controller and position indicator
module (81384001), which includes motor power relays and provides several important
operating features. This module is sealed from the environment as long as all harnesses,
which use sealed connectors, are connected. The front panel of this module contains two
pushbuttons, used to operate the valve, and three high intensity LED’s, which indicate the
valve’s position. Intermediate harnesses from the module to the valve are available from
Elkhart Brass in several standard lengths. See Layout Drawings for part numbers.
III. VALVE OPERATION:
The push buttons on the panel-mounted module (81384001) are used to fully open and
close the valve or to place the valve in a throttled position. The pushbuttons are color
coded for quick interpretation and offer tactile feedback to the user. Pushing the green
open button will cause the valve to travel in the open direction, and pushing the red
button will cause the valve to travel in the closed direction. When opening the valve
from the fully closed position, there is a momentary delay to prevent the valve from being
cracked opened by an inadvertent push of the open button.
Hall Effect transducers located in the valve gear case precisely sense the valve open and
closed positions. The Hall sensors are digital, solid state devices that provide a switching
signal in the presence of a magnetic field. As the valve reaches either the open or closed
position, a small magnet moves into the sensing range of the Hall device. The Hall
device then changes state and causes motor power to shut off. This control feature
prevents high current, high torque stall loading of the motor and gear train.
A. Auto-Travel Feature:
A unique and valuable feature of the 2900E control system is its “Auto-Travel”
capability. The travel time from the fully closed to the fully open position is seven
seconds for all valve sizes. This travel speed assures precise valve throttling control, and
assures against rapid closure of the valve and the associated water hammer potential. The
Auto-Travel feature allows the pump operator to either fully open or fully close the valve
without the need to hold the pushbutton for seven seconds.
Auto-Travel can be initiated with the valve in any position. To initiate Auto-Travel the
operator holds down the pushbutton corresponding to the desired direction of travel.
While holding this button, the operator presses and releases the other button. Finally, the
operator releases the button corresponding to the desired direction of travel. The valve
will continue to travel in the desired direction until it reaches the fully open or fully
closed position. For the properly trained pump operator this feature is easy to use, but it
is highly unlikely that a less experienced operator will accidentally initiate Auto-Travel.
Once Auto-Travel has been initiated, pressing either button will cancel the operation.