Installation Manual PA Pro III
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2018-03-16 Page 10 of 30
5
Connection of sensors
Sensors should be placed in accordance with the supplied flowchart and connected to the system
as shown on the supplied wiring diagram. All sensors should be checked against room temperature
and atmosphere pressure before being attached. Check section 12 for troubleshooting.
5.1
Mounting of pressure transmitters/transducers
Pressure should be registered as close as possible to the compressor inlet and outlet. Pressure drop
between sensor and compressor will affect the accuracy.
5.2
Mounting temperature sensors
Temperature sensors may be mounted on the outside of piping with the ClimaCheck method due to
the inherent low sensitivity to temperature errors. This is a critical advantage compared to
traditional methods but should not be taken as an excuse to not follow the recommended
procedures below.
Temperature sensors should be mounted:
-
10-20 cm from the compressor, flanges, valves or other objects that can act change the
surface temperature compared to the inner temperature of the tube.
-
Maximum contact should be ensured by:
▪
Removal of any insulation and paint on the tube.
▪
When mounted in pockets the sensor must be securely pressed against the wall of
the pocket.
▪
Heat transfer paste should always be used for surface and “pocket” mounted
sensors.
-
Aluminium tape should always be used for surface mounting.
-
Insulation should be carefully done and diffusion tight if the surface/object is cold. The
openings of dip tubes/pockets should be sealed/covered with insulation.
-
In the case of PT1000 sensors with red four lead cables, the pairs with the same colour
should be attached together to the terminals.
Figure 2 - Apply sensors with heat transfer compound, Aluminium and insulation
5.2.1
Required insulation
Many factors have an impact on required insulation to achieve good accuracy:
-
dT to ambient
High dT obviously increases the error from poor insulation.
-
Radiation from surrounding hot/cold surfaces.
