Watts tekmar 294, Инструкция по установке, эксплуатации и обслуживанию, Страница: 8 / 52

8 IOM-T-294
2205 © 2022 tekmar
+
-
EMS
+
Outdoor
Sensor
-
5 4
EMS Connection (Terminals 4, 5)
An Energy Management System (EMS) can be connected to the 294 to provide a target water
temperature . This signal replaces the outdoor air temperature sensor . Either a 0 to 10 V (dc) or
2 to 10 V (dc) signal may be used .
• Connect one wire from the EMS to the Outdoor (+) terminal 4 .
• Connect a second wire from the EMS to the Outdoor (-) terminal 5 .
A 0 - 20 mA signal can be converted to a 0 - 10 V (dc) signal by installing a 500 Ω resistor in
parallel between the Outdoor (+) and (-) terminals (4 and 5) . The EMS Signal setting must be
set to 0-10 .
A 4 - 20 mA signal can be converted to a 2 - 10 V (dc) signal by installing a 500 Ω resistor
in parallel between the Com (-) and EMS (+) In terminals (19 and 16) . The EMS Signal setting
must be set to 2-10 .
Mounting the Universal Sensors
These sensors are designed to mount on a pipe or in a
temperature immersion well.
The Universal Sensor should be placed downstream of a pump
or after an elbow or similar fitting . This is especially important if
large diameter pipes are used as the thermal stratification within
the pipe can result in erroneous sensor readings . Proper sensor
location requires that the fluid is thoroughly mixed within the
pipe before it reaches the sensor .
Strapped to Pipe
The Universal Sensor can be strapped directly to the pipe
using the cable tie provided . Insulation should be placed
around the sensor to reduce the effect of air currents on the
sensor measurement .
Immersion Well
If a Universal Sensor is mounted onto 1" diameter L type cop-
per pipe, there is approximately an 8 second delay between a
sudden change in water temperature and the time the sensor
measures the temperature change . This delay increases con-
siderably when mild steel (black iron) pipe is used . In general,
it is recommended that a temperature well be used for steel
pipe of diameter greater than 1
1
⁄
4
" . Temperature wells are also
recommended when large diameter pipes are used and fluid
stratification is present . If the well is not a snug fit on the sen-
sor tube, use the heat transfer paste . Apply paste to the sides
of the sensor and place a pea-sized globule on the sensor tip .
Push the sensor into the well and when it bottoms out, press
firmly . The paste will be forced up the sides of the well .
Conduit Connection
The Universal Sensor and Universal Sensor Enclosure 080
(sold separately) are specifically designed to mount onto a
3
⁄
8
" ID temperature well that is supplied with an end groove .
To install the well, plumb a ‘tee’ into the pipe and fix the well
into the ‘tee’ . The 080 enclosure has a
7
⁄
8
" back knockout that
must be removed and fitted over the temperature well . The
Universal Sensor is then inserted into the well and the retaining
clip supplied with the enclosure is snapped onto the well end
groove . If the well has a threaded end, the installer must sup-
ply a standard threaded conduit retaining ring . The two wires
from the sensor are connected to the terminal block provided
in the enclosure . The other side of the terminal block is used to
connect wires from the control .
Bottom of
Enclosure 080
Universal
Sensor
Cable Tie
Sensor
Well
Retaining
Clip
Universal
Sensor