The Safety-TL4896, a world first SIL2 rated temperature measuring device from Martens, which conforms to international boiler regulations offering a unique front panel installation is available from GHM Messtechnik South Africa. Certified to DIN EN14597 and DIN EN61508 the device gives an analogue actual value output for regulators and PLC eliminates the need for additional sensors.
Managing Director of GHM Messtechnik South Africa, Jan Grobler, said “The Safety-TL4896 is the first safety temperature measurement device in the world designed specifically for application in industries using boiler technology. I believe the device will generate enormous interest from plant operators from sectors such as paper and pulp, food and beverage, pharmaceutical, sugar, cleaning, hygiene and dairy”.
“The device operates as a direct indicator, because it is installed in the control panel instead of on the top-hat rail, eliminating the need for an additional ‘indicator’” said Grobler, adding “an additional advantage is the execution of the reset function directly on the device, removing the need for an additional control element” he said.
In boiler applications for hot water production, a safety temperature limiter must be provided in addition to the limit value monitor and minimum water level monitor in order to reliably suppress the energy supply in accordance with DIN EN 12828 – whether by
means of deactivating the automatic firing device with ignition flame monitoring (gas operation) or a safety valve (oil supply) or a heating current interruption – as soon as any of the limiters reacts. With self-sufficient device technology as required by DIN EN 61508
“Functional Safety”, i.e. independent of PLC systems, regulating systems and SCADA systems, only the permissible safety temperature limiters are used for industrial heat generators in accordance with DIN EN 14597 and the safety requirement level of functional safety in accordance with SIL2.
Combined heat and power plants require safety temperature limiters for self-sufficient monitors for the hot water, the over temperature of motor preheating, motor cooling water, exhaust gas and calorific value heat exchangers. In hot steam production, additional safety elements must be used in order to monitor boiler systems
equipped with over heaters.
The Safety-TL4896 safety temperature limiter has a safety shut-off contact and an adjustable pre-contact in order to warn of impermissibly high actual values independently of the regulating and control device.
Before the forced shut-off is activated, additional alarm messages can be issued and corresponding functional processes can be initiated in order to achieve a safe stand-by status, eliminate errors and avoid time-consuming and costly complete shut-downs and the subsequent restart of a plant. The high-quality analogue output of the actual process value offered with the Safety-TL4896 enables further processing in the automation
system and eliminates the need to install an additional sensor.
Electronic safety temperature limiters were previously often built, for example, as top-hat rail devices in switch cabinets. Now, for the first time, the device offers installation in the front panel. In the process, the actual and limit values on the large display can be read conveniently and the reset process after correction of the cause of an error takes place on the front panel in the same manner as for all other operating processes. As a result, separate devices and their wiring can be eliminated, because their functions are already integrated: indicator and reset button.
With the adjustable pre-alarm, no additional limiters are needed and a redundancy to the automation unit is provided. A second additional measuring chain is eliminated by the analogue output.
The Safety-TL4896 can be configured with the front buttons and tailored to the application.
Particularly with small and compact systems whose complete automation electronics are contained in the operating device (e.g. with use of the GHM-ONE multi-function device or a compact industrial PC/PLC system), there is no longer a large, conventional traditional switch cabinet. As a self-sufficient front panel unit in slim DIN format 48×96, the new Safety-TL4896 enables a consistently compact design of modern small systems, reduces the wiring work and facilitates ergonomic operation in the monitoring and observance of safety requirements.
The Safety-TL4896 offers time and cost advantages in wiring and installation. With the easy operation from the front side, the requisite safety functions and ergonomic
operation of safety temperature limiters is fulfilled for the first time.