Stock items of cables

Stock items of compensating cables

thermocables
Thermocouple sensors must be wired with right kind of materials between hot and cold junctions, in order to avoid measurement deviation caused by thermo voltages in connections of different materials. Cable types used are extension wires (X) or compensating cables (CA). The types stocked by Lapp Automaatio are compensating cables according to IEC 60584, with a temperature range of -50...+180 °C. The wires are multi-stranded, twisted in pairs and insulated with silicone rubber. The cable structure is _ × (2×1.5) mm². Static protection is implemented with a plastic-coated aluminum film, and the outer jacket is silicone rubber. *Trade product, not LAPP product Stock items are listed below:
Product
number
DesignationNumber of
cores and
wire size
Colors
+/–/sheath
Outer
diameter
mm
903242NiCr/Ni 2G ST 2G KCA 2x1.5grn/wht/grn7.50 (±0.15)
1084278NiCr/Ni 2G ST 2G KCA3x(2x1.5)grn/wht/grn9.50 (±0.15)
911884NiCr/Ni 2G ST 2G KCA6x(2x1.5)grn/wht/grn13.40 (±0.15)
1084281NiCr/Ni 2G ST 2G KCA8x(2x1.5)grn/wht/grn14.90 (±0.15)
903256PtRh/Pt 2G ST 2G SCA2x1.5ora/wht/ora7.50 (±0.15)
1002534PtRh/Pt 2G ST 2G SCA2x(2x1.5)ora/wht/ora8.50 (±0.15)
903257Fe/CuNi 2G ST 2G JCA2x1.5 bck/wht/bck7.50 (±0.15)
1210658NiCrSi/NiSi 2G ST 2G NCA2x1.5pnk/wht/pnk7.50 (±0.15)
Color short forms: bck = black, grn = green, ora = orange, pnk = pink, wht = white. Other cable types and wire structures can be delivered on request.

What is compensating cable (CA)?

Compensating cable

  • cable type is indicated with the letters CA (Compensating Alloy), e.g. for K type thermocouple the cable type is KCA.
  • wires have similar electrical features as the sensor's thermo wires, but they are not exactly same materials
  • this solution is more cost effective than extension wires, but the maximum temperature allowed is lower, depending on insulation materials in range of 100…200 °C.
Lapp Automaatio's stock items of cables for thermocouples are compensating cables.

What is extension cable (X)?

Extension cable or Extension wire

  • cable type is indicated with the letter X (eXtension), e.g. for K type thermocouple the cable type is KX.
  • wires are of exactly same materials as thermo wires of the sensor
  • these cables can reach even as high ambient temperature level as the thermocouple does.
TC = Thermocouple

CJC temperature of the cable end

Cold Junction Compensation = CJC

Compensating temperature measurement is needed in the point where compensating or extension cable is changed to copper cable. This point - cold junction - can be located e.g. by a terminal block inside a field enclosure or by terminals of a transmitter. More details on page: How do TC sensors work?

Cold Junction Compensating with PR temperature transmitters

  • If compensating cable is wired to PR 5100 series transmitter, a separate CJC connector must be changed on transmitter. CJC connector has a Pt100 resistor build in for measuring the connection temperature.
  • 2-wire transmitters of PR 5300/5400 series can be wired directly to terminal screws. These transmitters have an internal compensating sensor, which can be set on or off with software.