Installation guide

DRI-STEEM Vapor-logic 3 *OTUBMMBUJPOBOE0QFSBUJPO.BOVBMt1BHF
Temperature compensation offset option
This option is identified as a “T” in the second-from-last
place of your program code configuration string (for example:
EV11400285A7O
TX).
When selected as an option, DRI-STEEM provides a temperature
compensation (temp. comp.) transmitter. The temperature
compensation transmitter continually monitors interior window
glass temperature and transmits this temperature to Vapor-logic
3 .
Vapor-logic
3 assumes a 70 °F (21 °C) room temperature and uses
the glass temperature and the RH in the space being controlled to
calculate the dew point (°F or °C) for the space.
If the window temperature falls below the dew point, Vapor-logic
3
automatically decreases the RH set point so moisture does not form
on windows. The Idle screen displays the modified RH set point,
and an asterisk (*) appears next to the modified RH set point,
denoting that temperature compensation has taken control of the
RH set point. The “* Temp Comp” message appears on the status
line. When the interior window glass temperature rises above the
dew point, Vapor-logic
3 restores system control to the normal RH
set point for the space.
The transmitter provided with Vapor-logic
3 is calibrated for –20 °F
to 160 °F (–29 °C to 71 °C) with output from 4 to 20 mA. For
example, a temperature reading of 70 °F (21 °C) should produce a
measurement of 12 mA. You can calibrate the sensor by adjusting
the Temp Comp Offset in the Set Up menu.
Install using an 18-gauge (1 mm
2
) plenum-rated shielded (screened)
cable for transmitter wiring with grounding shield (screen)
at the shield (screen) ground lug in the control cabinet
(see
Figure 29-1).
8JSJOHTFOTPSEFWJDFTDPOUJOVFE
Figure 29-1:
Temperature transmitter wiring
OM-4031
21 VDC
sensor
window
mount
C.I.-T184H
common
Control panel
shield (screen)
ground lug
Place shunt
across “I˝ pins
of J16/19 when
connecting a 4-20
mA temperature
transmitter. See
Page 13 for more
information about
KVNQFSQJOT
J16/19
0 – 15 VDC
0 – 20 mA
0 – 150 ohm
RIV
2-wire, 18-gauge
(1 mm
2
) shielded
(screened) cable
OM-4030
VL3_IOM.pdf 33 11/19/2009 9:11:13 AM