STULZ Ultra-Series Humidifier Controller
(August, 2013)
7
Water Conductivity Probe
2.6.3
To ensure proper demineralized water supply quality, the
controller is equipped with terminal positions for the
connection of a conductivity probe. The conductivity probe
is shipped loose with a 10 ft. long cable. The conductivity of
the demineralized water is monitored via the sensor (probe)
mounted in the pipe supplying water to the Humidifier (see
Section 3.3.5). The controller alerts the operator with a
"High Conductivity Pre-alarm" if the water conductivity rises
to between 5 and 20 microSiemens.
Above 20
microSiemens, the controller shuts down Humidifier
operation following a 5 minute time delay and signals a
"High Conductivity" alarm.
Air Velocity Sensor
2.6.4
This controller is equipped with terminal positions for the
connection of an optional Air Velocity Sensor/Transmitter to
allow monitoring of the air flow in ductwork. The system
controller displays a “Low Airflow” or a "High Airflow" alarm
when the measured air velocity is outside the established
range (too high or too low). The system controller is
programmed to recognize an "Air Velocity" alarm condition
as a
Non-Critical
alarm. This alerts the operator of the
alarm condition but allows the Humidifier(s) to continue
operating.
Air
Proving
Switch
2.6.5
The controller is equipped with terminal positions for the
connection of an optional Air Proving Switch for use as a
safety feature. The switch contacts close when there is
sufficient airflow in the ductwork. The contacts open upon
loss of Airflow, triggering an alarm. The controller displays a
“Loss of Airflow” alarm when this occurs. Additionally, the
system controller is programmed to provide a “Summary
Alarm” indication. The system controller is programmed to
recognize a “Loss of Airflow” alarm condition as a “
Critical
Alarm
” and shut the Humidifier(s) down. The system will
automatically resume operation when airflow is restored.
Water
Leak
Detector
2.6.6
The controller is equipped with terminal positions for the
connection of optional Water Leak Detector(s). The water
leak detector(s) may be a spot or cable (20 ft.) type sensor.
The system controller is programmed to recognize a "Water
Leak" alarm condition as a
critical alarm
. Upon sensing a
water leak, the system controller shuts down Humidifier
operations and displays a “Water" alarm message. It
remains shut down until the cause has been determined
and corrected. Once corrected, the alarm can be reset.
Remote
On/Off
2.6.7
If the controller is configured for the Remote On/Off option,
terminal positions are provided to connect a remotely
located, On/Off switching control device. If the Humidifier is
turned on and the Ultra-Series controller receives a remote
input signal to turn it off, the controller disables all controller
outputs and provides a status message "Off by Remote
Shutdown". The humidification system is automatically re-
enabled when the remote On/Off signal calls for the unit to
turn back on.
Multiple Humidifier Grouping
2.6.8
The Ultra-Series controller can be configured to operate two
individual groups of Humidifiers (Figure 5) via a common
Modbus.
Figure 5 - Multiple Humidifier Groups
The 2 groups can be configured with duty assignments:
Rotating, Capacity-Assist, and Bank Select.
2.6.8.1 Group
Rotation
In Rotating mode, controller will rotate duty between the
Humidifier groups to promote equal run time. The rotation
time period is typically 1 week, however it may be set by the
user via the Factory menu. Call STULZ Product Support for
assistance when accessing the Factory menu.
2.6.8.2 Capacity
Assist
In Capacity Assist mode, the system can be used to
maximize efficiency for conservation of energy and to allow
more precise control of humidity production during periods
of low demand. The Capacity-Assist option enables one
group of Humidifiers to proportionally handle the demand
for humidification up to their maximum capacity. If the
output of the first group of Humidifiers reaches 100%
capacity and they are unable to satisfy the demand, the
controller enables the second group of Humidifiers to
operate, controlling their output proportionally while the first
group continues to operate at 100% capacity. As humidity
conditions approach set point, the controller scales back the
proportional output control signal to the second group
accordingly until they are no longer required. At this point
