AERCO Electronic Control Valve - Manual (Page 13)

VA-115 INSTRUCTIONS – ELECTRONIC CONTROL VALVE, CXT-E
3-1
3 - ADJUSTMENT
INTRODUCTION
Place the AERCO Heater (or other equipment being controlled) into operation in accordance with the
instructions furnished with the Heater (or other equipment).
WARNING
The Upstream Steam or Boiler Water Shutoff Valves MUST be closed prior to
performing the following adjustment procedures. Failure to observe this
WARNING may result in personal injury.
CONTROL VALVE TYPE CXT-E ADJUSTMENT
All CXT-E Actuators are powered by 24 VDC and are controlled by a linear 4-to-20 mA control signal. A 4
mA control signal input places the Control Valve in the fully-closed position; while a 20 mA signal strokes
the Valve to the fully-open position.
The Control Valve Actuators are self-calibrating for all Valve sizes. Therefore, simply proceed as follows
to automatically adjust the Actuator:
NOTE
The following adjustment procedure must be performed any time that the CXT-E Actuator
is replaced or a mechanical adjustment is made to the Linkage Assembly or Valve.
1. Refer to Figure 3-1 and loosen the Actuator cover set screw.
2. Remove the Actuator cover to access the PC Board containing the terminal connections, DIP
switches, Auto-Stroke (Reset) button and LED shown in Figure 3-1.
NOTE
If the Control Valve is furnished with an AERCO Electronic Control System (ECS), power
is applied to the Valve Actuator when the Control Box POWER switch is set to ON.
3. Apply 24 VDC power across Actuator pins 2 (+) and 1 (Common). The LED will light indicating that
power is applied. Wait approximately 10 seconds while the unit performs a self-test. Upon successful
completion of the self-test, the LED will blink 3 times and then go off.
4. For full-stroke automatic adjustment, press the Auto-Stroke (Reset) button. The LED will light.
5. The Actuator will then rotate in both directions to find its open and closed Valve position stops.
6. Upon successful completion of the automatic adjustment, the LED will blink 3 times and then go off..
7. Turn off power to the Actuator. Replace and secure the cover by tightening the set screw.