Operating instructions

22
Figure 22-1: Temperature compensation
transmitter placement
Double
pane
window
glass
Secure temperature
sensor tip to inside
surface of window glass
using clear RTV silicone
adhesive
Typical
sensor
cord routing
Surface-mounted
thermostat
temperature
control
box on wall
Thermostat
control wires
Window
framing
Temperature compensation offset option
This option is identified as a “T” in the second-from-
last place of your program code nomenclature (for
example: EV11400285A7OTX).
When selected as an option, DRI-STEEM provides a
temperature compensation (temp comp) transmitter.
The temperature compensation transmitter
continually monitors the interior window glass
temperature and transmits this temperature to
VAPOR-LOGIC
®
3
. VAPOR-LOGIC
3
then compares
the glass temperature to the desired RH set point in
the humidified area and calculates the dew point (°F)
for the space.
VAPOR-LOGIC
3
will lower (offset) the desired RH
set point so that moisture does not form on windows.
The keypad/display will show the amount of offset
that has taken place as a modified set point. As the
interior window glass temperature increases,
VAPOR-LOGIC
3
will reduce the offset and restore
system control to the normal RH set point for the
space.
Installation:
Temperature compensation transmitter
Installation
Temperature compensation transmitter.
The transmitter provided with VAPOR-LOGIC
3
is
calibrated for -20°F to 160°F (-29°C to 71°C) with
output from 4-20 mA. For example, a temperature
reading of 70°F should produce a measurement of
12 mA.
Install using an 18-gauge plenum-rated shielded
cable for transmitter wiring with grounding shield at
the shield ground lug in the control cabinet (see
Figure 21-1 on the previous page).
Temperature compensation
transmitter placement
See Figure 22-1 below.
1. Position the temperature compensation
transmitter control box on a wall adjacent to a
window frame facing north or northeast.
2. Place flat surface of temperature sensor tip on
lower corner of glass surface.
3. Temporarily hold the sensor tip in place with
strips of masking tape.
4. Apply a small amount of clear RTV silicone
adhesive over and around the sensor tip (making
sure the sensor tip is in contact with the window
glass).
5. After adhesive has cured, remove masking tape.
OM-337