Valves; Controls; Microprocessor Control User Interface - Ingersoll Rand EH Serie Manual De Operador

7.5 VALVES

Flow and Purge Valves are two-way valves that are switched using air-
operated double-acting actuators. Each valve is actuated by a four-way
solenoid valve as shown on the P & ID.
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 the Inlet Flow Valves
supply control 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 the Purge Valves supply control
air to the "closed" port on the appropriate valve actuator.
BUTTONS
• ON
Initiates PLC program.
switching functions.
• OFF
Stops PLC program. Stops valve switching functions.
Shutdown Sequence. Opens Inlet Flow Valves.
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 modify set point values. Set point values cycle
through a fixed range. Also allows entering negative numbers in
Technician.
•
Allows user to step backwards to the previous level of the menu.
7.0 PRINCIPLES OF OPERATION
PRESS ON
Figure 1 - Microprocessor Controller
Begins system monitoring and valve
Closes Purge
EH Series Desiccant Dryer Models 150-8000
http://www.ingersollrandproducts.com
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.

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.
• 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.
Initiates
• 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.
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