Walchem W900 Quick Programming Manual

Programming the W900 for Cooling Tower control (using keypad):

Conductivity sensor
Bleed Relay (Intermittent Proportional Control)
Feed Relay
Flow switch to lockout controls when no flow
To Confirm your controller is in HVAC mode.
1. From the Home screen, press Config
2. Select Global Settings
3. Press the DOWN Arrow until HVAC Modes is highlighted.
4. Press Enabled, and then

Programming the Conductivity Sensor

1. From the Main Menu, press
2. Select the sensor input that the conductivity sensor is wired to
3. Press
4. Press the DOWN Arrow until Type is displayed
5. Press Type
6. Use the DOWN Arrow to select Contacting Conductivity, and press the Check

Programming the relay for Bleed

1. From the Main Menu, press Outputs
2. Choose the relay for the blowdown valve
3. Press Configuration
4. Press the DOWN Arrow until Mode
5. Press Mode and choose On/Off and press the Check
6. Press Configuration
7. Press the DOWN arrow until you see Input
8. Press Input, and then select the Conductivity sensor. Press Check
9. Press UP or DOWN Arrow, then HOA Setting. Select AUTO
You've now programmed the relay for the blowdown valve, and programmed the sensor, and assigned
it to that relay.
W900 Quick Programming Guide
.
INPUTS
again