Paralleling Rtd Inputs For Dual-Channel Energy Measurement - Siemens SITRANS F Instruction Manual

Section 3
FUE1010EN Dual Channel Temperature Sensor Inputs
Keep the RTDs out of direct sunlight or other non-pipe sources of heat or cold which may affect their
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temperature sensing. The foam insulator supplied helps in this regard, but consider using additional
pipe insulation for all installations exposed to extreme ambient conditions. Consider mounting the
RTDs under the pipes in order to keep them out of direct sunlight.
In installations where the RTD elements are exposed to harsh conditions such as condensation, salt
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spray, etc., use C110 couplant to coat the connection between the cable and the RTD sensor. Consult
drawing # 991TN-7 for details.

3.2.4 PARALLELING RTD INPUTS FOR DUAL-CHANNEL ENERGY MEASUREMENT

Should you wish to measure liquid flow in the same pipe twice (perhaps at the supply and return location
of the line) but not redundently have to measure the temperature, the following information may prove
helpful:
Connect terminal #2 of terminal blocks TB1 and TB2 together and terminal #3 of TB1 and TB3. You can
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use any available hookup wire to do this. By doing this, you are not shorting terminals 2 and 3; just
interconnecting 2/2 and 3/3 of each terminal block.
Connect terminal #2 terminal blocks of TB2 and TB4 as well as Terminal #3 of TB2 and TB4. This
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hookup will result in the same temperature being reported for Tr and Ts for channels 1 and 2 of the
meter. It probably is a judicious idea to check the temperature to ensure that they do indeed match. Of
course, Td will be similarly identical. These temperatures can be checked in Diagnostics/Energy Data.
Be sure to accurately indicate where the flow is being measured in the "Location" item of the FUE1010EN
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menu; either supply or return.
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1010ENFM-3B