The first half of 20th century witnessed Industrial Revolution, where machines powered by steam, oil or electricity took over the manual work from man, leaving him to supervise the machines. The second half of the century saw chip revolution where microprocessors and computers have relieved the man from monotonous supervisory work. Today 4-20 milliampere Distribute Control Systems (DCS) are being used in continuous process plants like chemicals, refinery, fertilizers, cement, metal, power generation, etc. Here various parameters like temperature, pressure, flow, level etc. are converted in to milliampere signals with the help of transmitters and are sent to the control room. In control room these signals are analysed, compared and suitable commands are sent to the field to take corrective actions.
The control room has become the brain of the plant and the instrumentation cables carrying the signals and commands are the nerves of the plant. Fire and Gas detectors are keeping a constant vigil for possible fire or gas leaks. They are connected to the control room with the help of cables and any fire or gas leak is immediately transmitted to the control room for actions before any major damage is done. Thermocouples and Resistance Temperature Detector (RTD) are routinely being used for Temperature measurements in Industry. Proper cables must be used to connect the above with the Temp. Indicators to avoid any error in the measurements.
The signals in the above electronic circuits are in milliamperes or in microvolts and hence susceptible to outside interference. The cables carrying the signals i.e. Instrumentation Cables must be properly designed to screen off the external interferences over the lengths otherwise it may lead to malfunctioning of the system. Instrumentation Cables if properly selected and installed give trouble-free service for the entire life of the plant. There is no inside heating like that in the case of power cables and hence the aging of plastics is also negligible KENTER Cables provide a wide range of instrumentation cables for all types of applications in the process industry.
The detailed construction, conductor sizes, and electrical characteristics are as mentioned below. The company also manufactures custom-designed cables to meet the specific requirements of individual customer applications
Bare / tinned electrolytic annealed copper conductor. Solid, stranded or flexible confirming to BS 6360 and IS 8130. Conductor
Sizes of 0.5 Sq.mm. To 2.5 Sq.mm. are available as per requirement.
PVC/FR-LS PVC or HRFR PVC insulation in accordance with IS 5831. Polyethylene insulation in accordance with BS 6234
IS 6474. Also, XLPE and ZHFR insulation can be provided.
Required numbers of cores are laid up in case of multicore core cables. Individual pairs, triads, or quads are formed by uniformly twisting the insulated cores with short lay lengths, prior to laying.
(Optional) dependant on system requirements and environmental conditions to protect against interference created from other cables or other electronic/electrical/ mechanical devices. The shield is a 100% Aluminium foiled wrap with drain wire, of 0.5 sq.mm. tined copper conductor in continuous contact with the foil. Tin Copper braid screened can also be provided.
Galvanized steel round wire or strip armour in accordance with BS 5308 / IS 1554 respectively. The armour wire and strip confirming to IS 3975. S.S wire braid armour can also be provided.
PVC, HR, FRLS PVC, or ZHFR sheath in accordance with IS 5831 can be provided. U.V stabilized Polyethylene sheath can also be provided for hazardous areas. The blue colour outer sheath is used in intrinsically safe areas of plants for easy distinguishing.