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HB Series Desiccant Dryer Models 150-8000
ingersollrandproducts.com
7.0 PRINCIPLES OF OPERATION
7.5 VALVES
Actuated valves are two-way valves that are switched using double
acting actuators. Each valve is actuated by a four-way solenoid valve
as shown on the P & ID.
A
NOTICE
Actuated valves require 75 psi min. pressure for proper operation.
The Inlet Flow Valves are connected as normally open valves. When
the dryer is de-energized, the solenoid valves for these valves supply air
to the "open" port on the appropriate valve actuator.
Purge Valves are connected as Normally Closed valves. When the
dryer is de-energized, the solenoid valves for these valves supply air to
the "closed" port on the appropriate valve actuator.
Outlet Check Valves, as well as Purge Check Valves, are single
direction check valves that will allow flow in the direction shown on the
P&ID but not allow flow in the opposite direction. Valve positions must
be changed accordingly for the appropriate mode selected.
7.6 CONTROLS
7.6.1
MICROPROCESSOR CONTROL USER INTERFACE
The Microprocessor Control display provides the user with the
operating parameters and their corresponding values. When
power is supplied to the dryer, the Microprocessor Control will
illuminate and default to the "Standby" mode, displaying the
"Press ON" prompt.
The following illustration summarizes the keypad functions.
Figure 1 - Microprocessor Controller
BUTTONS
• ON
Initiates PLC program. Begins system monitoring and valve
switching functions.
• OFF
Stops PLC program. Stops valve switching functions. Initiates
Shutdown Sequence. Opens Inlet Flow Valves. Closes Purge
Valves.
• SELECT DISPLAY
Allows the user to scroll through the available displays. The last
display selected will remain displayed as the default display.
• + / -
Allows user to increase set point values. Set point values cycle
through a fixed range. Also allows entering negative numbers in
Technician Mode.
•
Allows user to step backwards to the previous level of the menu.
• RESET
Pressing once clears the local alarm indication and de-energizes
the remote alarm contact for many alarm conditions. Should the
alarm condition persist, the alarm will return after the alarm inhibit
time has expired.
• SET
Permits the adjustment of parameters in TECHNICIAN MODE.
• ENTER
Used to accept changed parameters and set point values.
• TEST
Not used in Desiccant Dryer applications
• i
Restricted Level access for factory use only.
PRESS ON
120.26 Dryer - Operation, Installation, Maintenance Manual, and Parts
