IWAKI AMERICA Walchem W900 Quick Programming Manual

W900 Biocide Programming Guide
ONLY AVAILABLE IF HVAC MODES ARE ENABLED IN CONFIG MENU – GLOBAL SETTINGS

Basic Biocide Operation

How the Biocide Addition works:
When a biocide event triggers, the controller will first prebleed (if a prebleed is programmed)
for the set amount of prebleed time or down to the set prebleed conductivity. Then the biocide
relay is turned on for the set duration. This is followed by a post-bio add lockout that blocks the
bleed relay from turning on for a set amount of bleed lockout time.
You can program when, how often, and for how long the biocide comes on, in addition to a pre-
bleed and a lockout (after the biocide addition) as mentioned above.
When in the Biocide mode, you program *Events* for the relay. And Event means that the
output is turned on at the same time of day, for the same amount of time, and except for the
Daily cycle, on the same day of the week.
When programming the event, you select the Repetition of the biocide event, (Daily, Weekly, 2
Week, 4 Week, None), the Day and the Time the relay comes on.

Enable HVAC Mode

Start from the Main Menu (from the home screen press
Config
1. Press
2. Press Global Settings
3. In Config > Global Settings, you can enable HVAC Modes.

Programming the Biocide Timer Control Mode

The following instructions will show examples of how to program the controller for biocide feed on a
Daily, Weekly, 2 Week, 4 Week, and None basis.
W900 Quick Programming Guide
and then Config