RH CGS-240, Руководство пользователя

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Subsystems
CGS-240 Manual 6/15/2021
Page 60 of 148
SD1 is configured for communication on address 0 at 9600 baud, 8 data bits, 1
stop bit, no parity. SD1 is powered by 24VDC from 24V and UART2_
GND.
Based on positioning commands from the ECB, the stepper controller actuates
the stepper motor. A single, optical limit switch, SW1, connects to the stepper
controller’s X3 digital input and identifies the valve’s fully closed (home)
position.
6.2.4 PRESAT SELECT SOL 3S / PRESAT BYPASS, SOL 3B
Gas leaving the flowmeter is directed toward the presaturator.
When generating at low temperature and humidity conditions,
it may be advantageous to bypass presaturation and inject the
gas directly toward the saturator. A latching valve is driven by
two solenoids (SOL 3S for presaturator selection and SOL 3B for
presaturator bypass) that work together to create the
select/bypass function. Momentarily energizing SOL 3S via a
short pulse of 24 VDC from ECB RLY3 latches the valve to the
presaturator gas path. Momentarily energizing SOL 3B via a
short pulse of 24 VDC from ECB RLY4 latches the valve to the
preset bypass gas path.
As the latching valve is a pressure assisted valve (externally
piloted valve), external pilot pressure is obtained from the system’s regulated air inlet pressure.
6.2.5 EXPANSION VALVE, V 2
The expansion valve, V2, is a stepper-motor-drive valve used for
controlling saturation pressure at any given flow rate through the
system. The stepper motor is positioned by a stepper controller, SD2.
The ECB communicates with the stepper controller via UART2
configured for 2-wire RS-485 communication. Commands are sent to
and received from the stepper controller via UART2_ D+ and D-. SD2
is configured for communication on address 1 at 9600 baud, 8 data
bits, 1 stop bit, no parity. SD2 is powered by 24VDC from UART2_
+24V and UART2_ GND.
Based on positioning commands from the ECB, the stepper controller
actuates the stepper motor. A single, optical limit switch, SW2,
connects to the stepper controller
’s X3 digital input and identifies
the valves fully closed (home) position.
Figure 6.10
Figure 6.12
SOL 3B
SOL 3S
Latching
Valve
Figure 6.11