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.
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.
Supply valves use normal operation and exhaust and hood valves use reverse operation. For normal operation settings, see Figure 41. For reverse operation settings, see Figure 42.
