Power management company Eaton has introduced new MTL830 range multiplexers for Zone 0 hazardous area temperature measurement applications, aiming to improve the form factor to minimise hand wiring and simplify installation and maintenance, as well as making them RoHS compliant
The MTL830 range of multiplexers avoids the need to isolate each instrument loop, reducing the cost of installed wiring by up to 50 per cent by communicating the input of multiple hazardous-area temperature sensors over a single twisted pair data highway. Further savings are achieved by reducing the number of inputs to the control system, cabinet space and weight.
MTL831C multiplexer transmitters are normally sited in the hazardous area, typically mounted close to field instruments in an IP65-rated enclosure, supporting thermocouple, RTD and mV analogue sensor inputs. Compatible safe-area MTL838C receivers translate the information transmitted from the MTL831C via the data highway and provide serial Honeywell LLMUX or Modbus outputs, with status information, to feed to host PLC, PC or DCS controllers.
The single data highway cable, a simple twisted pair or pair of wires within an intrinsically safe (IS) multi-core cable, supports communication between the safe and hazardous areas over distances up to one kilometre, and also provides power to the transmitters.
“An important component in hazardous area temperature measurement applications, our MTL830 range multiplexers reduces installation time and costs for intrinsically safe hazardous-area cabling,” said Niaz Ahmed, associate product line manager at Eaton.
“We have invested in the development of the MTL830C multiplexer range to support our large installed base of temperature multiplexers worldwide. This allows migration of MTL830B installations to MTL831C and MTL838C products whilst retaining the same sensors, cabling and control system interface,” Ahmed added.
The multiplexer system aims to communicate the status of up to 32 inputs, reducing the number of hazardous area wiring pairs from 32 to one. This saves installation time and further reduces costs by eliminating long runs of expensive thermocouple compensation cable from the hazardous to the safe area.
