Installation guide

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Aquastat operation
The aquastat set point is the minimum tank temperature the
Vapor-logic
3 controller should maintain when there is no call for
humidity. It is adjusted through the Set Up screen. This feature
shortens the tank preheat time, which provides an even quicker
response to a call for humidity.
For example, if the aquastat is set at 180 °F (82 °C) when a call for
humidity occurs, the tank only needs to warm up 32 °F (18 °C) to
reach the boiling point and start producing steam. However, if the
aquastat is at its minimum default setting of 40 °F (4 °C) and the
tank is in an average-temperature occupied room, the tank will
be about 70 °F (21 °C). In this situation, when a call for humidity
occurs, the tank needs to warm up 142 °F (79 °C) to reach the
boiling point and begin producing steam. When an aquastat call is
heating the tank, the “Aquastat Heating” message appears on the
Idle screen.
This feature is standard on all DRI-STEEM humidifiers with
Vapor-logic
3 control except Steam Injection humidifiers.
Freeze protection
Freeze protection is similar to the aquastat with several notable
exceptions. The freeze protect set point is fixed at 40 °F (4 °C).
Its sole purpose is to prevent the tank from freezing in cold
environments. Unlike aquastat, if a condition exists that prevents
the heaters, burners, and valves from firing (such as an alarm, an
external interlock switch is open, or the humidifier is in Standby
mode), instead of remaining idle, the tank drains to prevent
freezing.
When the tank is heating or draining to prevent freezing, the
“Freeze Protection” message appears on the Idle screen.
This feature is standard on all DRI-STEEM humidifiers with
Vapor-logic
3 control except Steam Injection humidifiers.
Aquastat, freeze protection operation
VL3_IOM.pdf 76 11/19/2009 9:11:16 AM