The valve actuator can be set for normal or reverse operation. This ensures that
fail-safe actions are achieved. The fail-safe modes include loss of power and loss of
signal. The UVM has a setting, either through the UVM Configuration Tool or by an
enabled DIP switch to select the normal-reverse mode of operation. Set the
normal/reverse acting DIP switch, if enabled, or select the reverse operation check box
in the Misc Tab of the UVM Configuration Tool to the preferred mode of operation. If the
reverse setting is selected, set the actuator to reverse acting and invert the command
signal from the third-party controller. This applies to revisions 0.75 and upwards The
reverse operation signal from the OEM controller is 10 V to 0 V for 0 to xxxx CFM, and
the actuator output control signal from the UVM is 20 mA to 4 mA for 0% to 100%
positioning. The feedback signal is always 0 V to 10 V for 0 to xxxx CFM, it is never
inverted. For normal operation used for supply valves and reverse operation used for
exhaust and hood valves, the settings shown in the following figures are recommended for
UVM revisions 0.75 onwards. Earlier revisions do not invert the UVM input signal. For
normal operation settings, see Figure
24. For reverse operation settings, see Figure 25. Valve calibration label
Normal operating mode Reverse operating mode.
Figure 1. Valve calibration label
Figure 2. Normal operating mode
Figure 3. Reverse operating mode
