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XT SERIES INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
Principle of operation
1. CONTROLLER RECEIVES A CALL FOR HUMIDITY
When the RH level in the humidifi ed space drops below set point, the humidifi er controller
receives a call for humidity and calculates a corresponding electrical current. The controller
closes the contactor, which energizes the electrodes. If there is not enough water in the steam
cylinder, the fi ll valve opens and water enters the steam cylinder.
2. ENERGIZED ELECTRODES BOIL WATER INTO STEAM
When the water level in the steam cylinder rises to touch the electrodes, electrical current fl ows
through the water between the electrodes. Electrical resistance in the water causes the water to
heat up and boil into steam. The steam fl ows through the steam outlet and through steam hose or
tubing to the XT steam blower or dispersion assembly, where it is discharged into the airstream.
3. ELECTRICAL CURRENT INCREASES TO MEET DEMAND
As the amount of water covering the electrodes increases, current fl ow increases. The fi ll valve
remains open until the amperage increases to 10 percent above the current corresponding to
the demand signal. Then the fi ll valve closes, and the water boils into steam.
4. WATER CONTINUES TO BOIL INTO STEAM
As the water boils into steam, the amount of water covering the electrodes decreases,
and current fl ow decreases. When current fl ow decreases to 10 percent below the current
corresponding to the demand signal, the fi ll valve opens to increase the water level in the steam
cylinder, which increases current fl ow and steam production.
5. CONTROLLER INITIATES DRAIN/FILL CYCLES TO FLUSH CONDUCTIVE IONS
As steam production continues, the concentration of conductive ions in the water increases,
eventually leading to increased electrical current through the water. An algorithm monitors
water conductivity and auto tunes drain and fi ll cycles to keep electrical current within demand
parameters. This optimizes humidifi er performance based on water conditions and steam
production.
The
humidifi er has user-selectable drain water tempering. When drain water tempering is
selected, drain water is automatically cooled before entering the drain.
WATER CONDUCTIVITY
In electrode humidifi ers, steam output is directly related to the resistance of the water in the steam
cylinder and, therefore, the conductivity of the water between the electrodes. Higher water levels
cover more electrode surface and result in more steam; lower water levels cover less electrode
surface and result in less steam. Since water conductivity and water level both correlate to steam
output, DriSteem’s algorithm monitors conductivity and manages drain and fi ll cycles to optimize
humidifi er performance and provide proper steam output.
DRAIN AND FILL CYCLES
As the water in the cylinder boils into steam, the concentration of conductive ions increases until it
reaches a threshold that triggers a drain and fi ll cycle. This rids the cylinder of highly conductive
water and replaces it with less conductive fi ll water. The more conductive the fi ll water and the
higher the demand, the more quickly the threshold is reached, and the more frequently the cylinder
automatically drains and fi lls to stay within the parameters for proper steam output.
OPERATION
