EC: SSX/SST Safety Isolator and Splitter

Safety - Process safety, intrinsic safety: exida IEC 61508:2010 certified SSX 2-wire and SST 4-wire safety isolators and splitters from Moore Industries provide isolation and signal conversion for SIS, protecting and enhancing loops while passing valuable HART data from field transmitter to host systems. This is a Control Engineering 2014 Engineers’ Choice finalist.

October 17, 2013

The Moore Industries SSX 2-wire (loop powered) and SST 4-wire (line/mains powered) safety isolators and splitters were designed and built from the ground up in compliance with the strict IEC 61508:2010 standards for safety related applications and they are certified SIL 3 capable by exida for Safety Instrumented Systems. They isolate an SIS from a basic process control system (BPCS) or monitoring system so disconnections or failures to these secondary systems don’t affect the safety system. They protect safety systems from surges, spikes and transients in the field. With 1,500 Vrms isolating capability, the SSX and SST protect safety I/O cards and systems from the rigors of plant environments. Failure modes, effects, and diagnostic analysis (FMEDA) reports provide the required safety data to ensure that risk reduction requirements are met.

The 4-wire SST splitter will split signals between two locations. It takes in one signal and provides two fully isolated outputs that can be taken to two separate receiving devices. This facilitates maintenance on either output loop without losing the signal on the other output loop.

Built-in HART pass-through technology ensures that when loops use HART transmitters, that critical and valuable HART diagnostic, process, and calibration information can be read on either side of the SSX or SST. Most other isolators block and "strip off" the HART signal. When used as a splitter, the 4-wire SST also passes HART data to both asset management systems, programming devices or host systems.

The 4-wire SST is also capable of providing loop power to a 2-wire transmitter that is connected to its input. Plus, standard 20 V/m RFI/EMI protection is provided on both the SSX and the SST to protect against harmful effects of radio frequency and electromagnetic interference. 

Moore Industries