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BTU VENTILATION CORPORATION
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OFFICE 888-884-8070
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FAX 218-346-7485
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www.btucorp.com
XT-70 Control Panel
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above the setpoint, the humidifiers will run for the minimum off time during each cycle. A humidity cycle is com-
posed of 100 seconds. There can be any combination of On and Off cycles during this time. If running in the
auto mode, there will be a output ranging from 0 to 100%. With an output of 60%, for example, there would be
60 seconds of humidity on and 40 seconds of humidity off.
Front Panel Switches: Each of the humidifiers has a MOA switch on the front panel. These switches must be set
to Auto before the setting on the HMI can affect the operation.
Each of the humidifiers has different operations that can be selected.
MANUAL: If the humidifier is set to manual, it will run whenever the fans are on. Normally the cell should al-
ways be run in the Manual position. In the Manual position, the associated Time On, Time Off and Output are
not shown.
TIMER: In the Timer mode with the fans running, the humidifier will turn on for the programmed Time On and
then turn off for the programmed Time Off. Each of these timers can be set up to 100 seconds. The time is in
seconds. For example, if TIME ON = 20 and TIME OFF = 30, the humidifier would turn on for 20 seconds and
then turn off for 30 seconds and then repeat the cycle.
AUTO: In the Auto mode with the fans running, the humidifier will turn on and off automatically. The humidity
PID loop will look the humidity setpoint, the plenum humidity and generate a signal from 0 to 100%. This will be
displayed as the OUTPUT. The TIME ON parameter becomes the minimum desired on time. If the TIME ON =
30%, the PID loop will generate an output from 30 to 100%. If the output is equal to 60%, the humidifier would
be on for 60 seconds and off for 40 seconds.
EVAP ONLY: the Evap Only mode is used when minimum humidity is desired but evaporative cooling is still
needed. The cell will turn on only when needed for cooling and then turn off when it gets cool enough outside to
provide enough cooling without evaporative cooling.
After selecting the desired mode, press SAVE.