JUMO safetyM TA Multifunctional Safety Limiter, Type 701158

A configurable SIL 2 and SIL 3 limiter for temperature, pressure and level

The JUMO safetyM TA (type 701158) is a multifunctional safety limiter with fault tolerance for monitoring temperature, pressure, flow or filling level. The universal measurement input accepts RTD probes, single or double thermocouples and 4 to 20 mA standard signals. When a limit is violated, a relay that operates on the quiescent current principle drops out and switches the plant or machine to a safe state. The user can choose the safety architecture: the classic 1oo2D S structure that also serves as STB or STW to DIN EN 14597, a 1oo2D voter that allows a limited time of degraded operation for higher availability, or a 2oo2 structure. The datasheet quotes SIL 2 or SIL 3 to DIN EN 61508 and PL c to PL e to DIN EN ISO 13849, depending on the sensor arrangement. Extra outputs include an analog output, a second changeover relay for a pre-alarm, and a digital input.

Technical specifications

Reaching the target SIL

The achievable level depends on the sensor architecture. A single Pt100 in 2-wire circuit gives SIL 2 with 1oo2D logic, while two Pt100 or Pt1000 probes, two thermocouples or a mixed pair reach SIL 3. A variant without sensors lets the plant operator use any 4 to 20 mA sensor, but then the operator is responsible for the evaluation of the achieved SIL. The datasheet lists MTTFd limited to 100 years, DCavg of 90 % to 91 % and PFH values around 3 x 10 to the power -9 per hour for the dual-sensor variants, and the 1oo2D voter reaches PL e for a degradation time of 72 h and PL d at 168 h. The STB version stays locked after activation and needs a manual reset with a tool, under a sealable transparent cover.

Configuration and installation notes

Limiter mode requires a manual reset on the keypad or digital input once the value is back in the valid range, and the monitor mode resets itself. After a power failure the device returns to the safe state at first start-up. Know-how protection by code protects the configuration from being read or copied. Contact switching cycles are counted and flagged at an adjustable limit. In process heating, furnace, heat treatment and oven protection duty, install the limiter on a DIN rail and wire the alarm relay in the safety circuit of the heater contactor. Probe short-circuit, probe or line break and range overflow or underflow are detected and shown as arrows on the display, and a terminal-temperature fault outside -20 to +80 °C also forces the safe state. Use the USB port only for set-up, since the device enters a safe state while data are being transferred.

See controllers and data acquisition for related items.

Using the safetyM TA in Oman and the GCC

Safety limiters are used in the region on furnaces, ovens, heaters, boilers, thermal oil systems and dryers, where high temperature must switch the heating off independently of the control system. The safetyM TA can also limit pressure or level, which is useful on process skids and water heaters. In oil and gas, petrochemical and power plants, safety functions are often designed to IEC 61511 or IEC 61508, and the target SIL is set by the plant’s risk assessment.

To reach the stated SIL, the complete loop must be considered: the sensor, the limiter, the final element such as a contactor or valve, and the proof test interval. The safety manual describes the required architecture and settings. In hot control panels, check the ambient temperature at the device, as long-term heat reduces the life of electronics.

For new installations, the limiter is often combined with a JUMO temperature probe and a contactor or valve in the same order, so the loop is designed as one unit. Send the process description and the risk assessment target, and we can check the suitable variant and accessories before quoting.

Information to send with an enquiry

• Measured variable and sensor type
• Target SIL and architecture required
• Supply voltage and output requirements
• Quantity and any certificates needed

Related JUMO products: JUMO diraTRON 104 Compact Controller, Type 702114, JUMO miroVIEW Smart Digital Panel Indicator, Type 701580, JUMO IMAGO 500 Multichannel Process and Program Controller, Type 703590, JUMO dTRON 316 Compact Controller with Program Function, Type 703041, JUMO cTRON 04/08/16 Compact Controller with Timer and Ramp Function, Type 702070 and JUMO iTRON 04/08/16/32 Compact Microprocessor Controller, Type 702040.

Documents and quotation

The hosted document is JUMO data sheet 701158 (22 pages, English). It includes safety figures, dimensions and order details. Confirm system function, sensor arrangement, supply and extra codes before ordering. Seven Star LLC is an independent supplier in Muscat; send the process, sensor type and required safety level for a quotation.