20
12.
Super Heat Alarm Type: The superheat alarm has the option of either being in the non-latching
mode, or completely disabled. If disable is chosen then there will be no alarm indication and the
system will not shut down based on a low superheat condition. To change the alarm type, press the
key on this screen until the correct type is blinking.
13.
Pressure Reducing Valve Duty/Standby Screen: When using two pressure reducing valves in
the system one must be designated as the duty (active) pressure reducing valve, with the other
inherently in standby. On this screen the user can select whether they want the pressure reducing
valve in relay 1 active or the pressure reducing valve on relay 5 active.
14.
Modbus: This screen enables the user to adjust the Modbus communication settings to be able to
communicate with a SCADA system. Refer to separate “MODBUS Communication Manual” for
details.
15.
Pressure Range Screen: If desired, a different scale pressure transmitter may be used to monitor
pressure. The new span must then be adjusted on this screen to match the incoming 4-20 mA
signal. Consult Hydro Instruments before changing pressure ranges or pressure transmitters.
16.
PID Control Setting: This screen displays and allows the user to adjust the PID control settings
of the vaporizer. The user can adjust the control water temperature set point (S), the gain (G), the
integral (I) and the lag time (LT). Live values are also displayed on this screen such as, control
water temperature (T), heater output (O), and the integral error (E).
17.
Heater Element Sheath Temperature: This screen displays the temperature of the heater
elements. It is used for diagnostic purposes only and to trigger disconnection of power to the
heater if the temperature rises too high.
18.
Gas Type: This screen allows the user to select the chemical feed type depending on the
application. Choices are between chlorine (Cl
2
), sulfur dioxide (SO
2
), and ammonia (NH
3
).
