Amico Dome Loaded Manifold NFPA - Manual (Page 21)

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Manifold Switch Over
After electrical power has been applied to the manifold, the side pressurized first is designated the primary or “In Use”
bank. In order to simplify the following explanation, we will arbitrarily select the right side of the manifold as the primary
bank. The Green “In Use” LED on the right side will be illuminated and the Yellow “Ready” LED on the left (secondary) bank
will be illuminated.
The Solenoid valve directs dome bias pressure to the bank regulator on the right side. If we use a 55 psi oxygen manifold
as an example, the output of the right bank pressure regulator is approximately 155 psi (100 psi base pressure + 55 psi
bias pressure).The output of the left bank regulator is a approximately 100 psi (base pressure only, no bias pressure).
Since the bank regulator on the right side has the highest pressure, all flow is supplied by the right bank of cylinders.
As the cylinder pressure on the right side depletes, the pressure transducer on that side signals to the circuit board
to switch the solenoid valve. The solenoid valve then vents the dome bias pressure from the right bank regulator and
directs the bias pressure to the left bank regulator. The Green LED “In Use” on the right side goes out and the Red “Empty”
LED illuminates, indicating a Reserve In Use alarm with the Yellow LED on the left turning off and the Green LED being
illuminated.
When cylinders on the right side are replaced and pressure is restored, the right pressure transducer sends a signal to
the circuit board which, in turn, cancels the remote switchover alarm and the Red “Empty” LED turns off and the Yellow
“Ready” LED gets illuminated.
Since the left bank regulator has the dome bias pressure applied, its output pressure is boosted to approximately 155
psi. The right bank regulator has no dome bias pressure and its output pressure is controlled only by base pressure (100
PSI). All flow is supplied by the left bank of cylinders until the pressure drops to approximately 120 psi, then the pressure
transducer sends a signal to the circuit board causing a switchover to the right side in the same fashion as previously
described.
NOTE:
In the event of a power fluctuation or failure, a switchover alarm will be activated on the master alarm panels.
• The solenoid valve will direct dome bias pressure to the left tank, which is the default side, if the right side is In
Use.
• If the left side is In Use, the solenoid valve will continue to direct dome bias pressure until the bank depletes
before the right side takes over.
• The solenoid will not prevent the flow from being supplied no matter which side is in-use and until the system
is fully depleted of gas.