Eaton MTL

MTL Instruments Group



Eaton’s MTL830C range multiplexers adds RoHS compliance and improved form factor

2018 09 27
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Power management company, Eaton has released updated versions of its MTL830 range multiplexers for Zone 0 hazardous area temperature measurement applications, improving 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% 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 IS (intrinsically safe) multi-core cable, supports communication between the safe and hazardous areas over distances up to 1km, and also provides power to the transmitters – no additional field power is required. If the multiplexer transmitter is located in the hazardous area, the data highway must be protected by an MTL5053 IS digital isolator.

“An important component in hazardous area temperature measurement applications, our MTL830 range multiplexers reduce installation time and costs for intrinsically safe hazardous-area cabling” said Niaz Ahmed, Associate Product Line Manager, 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 ”

By using two transmitters and one receiver, the multiplexer system can 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. Also, if 3- or 4-wire RTDs are used, costs are reduced by terminating each RTD at the transmitter or its enclosure, without the need for additional wiring or components.

For more information on our MTL830 range of multiplexers click here.