General Information
The Humid•Alert® humidity sensor provides reliable monitoring of an area where a single high
or low humidity limit is critical. The HA-1 monitors relative humidity from 20% to 80% RH,
activating an internal switch output when the critical limit is exceeded. This output can be used
to activate alarm systems, telephone dialers, or other warning devices. This is a single set-point
device; it can monitor for either a high or a low level, but not both. If additional monitoring
(high and low) is required, Winland’s EnviroAlert® line of products with humidity monitoring
accessories is recommended.
Theory of Operation
The HA-1 senses the ambient room humidity using a nylon-banded sensing element. The HA-1
requires no power to operate and provides a SPDT contact output when the single set-point
is met. Humidity should be expected to vary from room to room and from one area of a room
to another. Ventilation and airflow will greatly affect relative humidity. The single set-point is
established by using the adjustment knob on the face of the unit.
Location
Choose a location for the Humid•Alert about five feet above the floor on an inside wall
with average room temperature and relative humidity conditions. The maximum ambient
temperature at the selected location must not exceed 125°F (51°C).
NOTE: Temperatures above 90°F (32.2°C) will adversely affect the accuracy of the Humid•Alert.
Installation
The HA-1 has three mounting options: horizontally positioned single-gang wall box, direct wall
mount, and duct mount.
NOTE: Only use the rubber mounting gasket when mounting the HA-1 to a duct; use in any
other application will limit natural airflow reducing the accuracy of the unit.
To install onto a single-gang wall box:
1) Run low voltage wiring from alarm panel,
dialer, etc. to chosen location through the
wall into the single-gang wall box. Plug
openings in the sides and back of the
box to prevent drafts from affecting the
Humid•Alert’s operation.
2) Remove the Humid•Alert cover by prying
with a screwdriver in the notch on the
bottom of the case (Figure 1).
3) Mount the base of the unit onto the single
gang wall box using the screws provided.
4) Make the wiring connections to the
Humid•Alert assembly using lead wires and
wire nuts supplied (Figure 2). Tuck wires into
the bottom of the base, and then snap the
cover assembly onto base (Figure 2).
To install directly onto a wall:
NOTE: If installing on sheetrock, use sheetrock
anchors and screws.
1) Drill a small hole in the wall and run low
voltage wiring from alarm panel, dialer,
etc. to the location chosen. Pull about six
inches of wire through the hole. Plug the
opening to prevent drafts from affecting the
Humid•Alert’s operation.
2) Remove the Humid•Alert cover by prying
with a screwdriver in the notch on the
bottom of the case (Figure 1).
3) Mount the base of the unit onto the wall
using the hardware provided.
4) Make the wiring connections to the
Humid•Alert assembly using lead wires and
wire nuts supplied (Figure 2) Tuck wires into the bottom of the base, and then snap the
cover assembly onto base (Figure 2).
To install onto a duct: Follow instructions printed on the adhesive mounting template.
Setting the Humidity Limit
Select an acceptable high or low humidity limit by turning the adjustment knob on the face
of the unit. For all installation options it is recommended that once the unit is installed the
current ambient RH level is determined prior to setting the HA-1 high or low limit. To determine
the current RH level, turn the adjustment knob on the face of the unit until you hear a “click”.
The point at which you hear the output contact change is the current relative humidity level.
Always allow enough time for the sensor to acclimate to current room conditions before
considering the reading to be accurate.
NOTE: The HA-1 has a built-in 2-3% hysteresis (delay). Therefore, the unit will not set and reset
at exactly the same point. This spread will amount to approximately 2-3 %RH of the alarm set
point.
If protecting against low humidity, assume continuity between C and NC under non-alarm
conditions. When the actual humidity drops below the set point, C to NC will then be open. To
test this configuration with the limit set below the current reading, rotate the knob clockwise
until the output contact changes.
If protecting against high humidity, assume continuity between C and NO under non-alarm
conditions. When the actual humidity rises above the set point, C to NO will then be open.
To test this configuration with the limit set above the current reading, rotate the knob
counterclockwise until the output contact changes.
Figure 1
Figure 2
