Spectrum Controls 1746sc-NI8u - Manual (Page 18)

6 SLC 500 ™ Universal Analog Input Module
Compatibility with RTD and Resistance devices and
cables
The module is compatible 100 Ω Platinum 385, 200 Ω Platinum 385, 55 Ω
Platinum 385, 1000 Ω Platinum 385, 100 Ω Platinum 3916, 200 Ω Platinum
3916, 500 Ω Platinum 3916, 1000 Ω Platinum 3916, 10 Ω Copper 426, 120 Ω
Nickel 618 and 120 Ω Nickel 672 RTD types and 3000 Ω resistance inputs,
and 3 possible wire types (2 wire, 3 wire, or 4 wire). Each RTD input
individually supports four input pins on the terminal block: one excitation
current source (EXC+), one excitation current drain (EXC-), one sense
positive (CH+) and one sense negative (CH-). Only those pins are
connected that are required by the selected RTD or resistance wire type.
For 2, 3, or 4 wire configurations, the module can support a maximum
combined cable length associated with an overall cable impedance of 25
ohms or less without exceeding its input limitations. The accuracy
specifications provided herein do not include errors associated with
unbalanced cable impedance.
Since the operating principle of the RTD and resistance inputs is based on
the measurement of resistance, take special care in selecting your input
cable. For 2-wire or 3-wire configuration, select a cable that has a
consistent impedance throughout its entire length. For 2-wire
configurations, we recommend that you use Belden #9501 (or
equivalent). For 3-wire configurations, we recommend that you use
Belden #9533 (or equivalent) for short installation runs (less than 100
feet) or use Belden #83503 (or equivalent) for longer runs (greater
than 100 feet) and in high humidity environments.
Table 1.8 Cable Specifications
Description Belden #9501 Belden#9533 Belden#83503
For 2-wire RTDs and For 3-wire RTDs and For 3-wire RTDs and
When used? potentiometers. potentiometers. Short potentiometers. Long
runs less than 100 feet runs greater than 100
and normal humidity feet or high humidity
levels. levels.
Conductors 2, #24 AWG tinned 3, #24 AWG tinned 3, #24 AWG tinned
copper (7x32) copper (7x32) copper (7x32)
Shield Beldfoil aluminum Beldfoil aluminum Beldfoil aluminum
polyester shield polyester shield polyester shield
w/ copper drain wire. w/copper drain wire. w/copper drain wire.
Insulation PVC S-R PVC Teflon
Jacket Chrome PVC Chrome PVC Red teflon
Agency NEC Type CM NEC Type CM NEC Art-800, Type CMP
Approval
Temperature 80°C 80°C 200°C
Rating