JUMO safetyM STB/STW Safety Temperature Limiter

Overview

JUMO safetyM STB/STW is a safety temperature limiter and safety temperature monitor built to DIN EN 14597, engineered to reliably detect and avert hazards to personnel, the environment, and production plant that could arise from thermal process malfunctions. Configurable as either a safety temperature limiter (STB) that requires manual reset after a trip, or a safety temperature monitor (STW) that automatically resets once the process temperature returns within the safe band, the JUMO safetyM STB/STW switches thermal systems to a safe operating state the instant a monitored process crosses its configured limit.

As the official authorized partner and exclusive regional representative for JUMO, Seven Star LLC proudly supplies the JUMO safetyM STB/STW safety temperature limiter/monitor to industrial, thermal process, and machine building customers across Oman and the wider GCC. Every unit shipped through Seven Star LLC is genuine JUMO product with full manufacturer warranty and access to local technical support – ensuring facility engineers and procurement teams in Muscat, Sohar, and Salalah receive an authentic, factory-certified JUMO safetyM STB/STW backed by regional service.

Working Principle

The JUMO safetyM STB/STW continuously monitors the process temperature via connected Pt100, Pt1000, or thermocouple sensors, comparing the measured value against a configured limit value. When the temperature crosses that limit, the device’s LED indicators (K1, K2) illuminate for the affected channel and the integrated relay output alarm switches the connected plant into a safe operating state, referred to as the alarm zone. A device built to the STB configuration requires deliberate operator acknowledgment to reset after tripping, ensuring a hazardous condition is investigated before restart, while an STW configuration automatically resets once the sensor temperature has fallen or risen back past the limit by the configured switching differential.

What sets the JUMO safetyM STB/STW apart is its 1oo2D device architecture: two independent measurement and evaluation channels continuously cross-check one another, giving the device the safe fault-detection capability required by DIN EN 61508 and DIN EN 13849, and making it suitable for applications governed by the EU Machinery Directive 2006/42/EC. This dual-channel structure allows the device to achieve SIL 3 and Performance Level e (PL e) certification, providing functional safety assurance appropriate for high-consequence thermal process protection.

Engineering Design of the JUMO safetyM STB/STW

The JUMO safetyM STB/STW accepts a wide range of sensor inputs, including Pt100 and Pt1000 RTDs (DIN IEC 60751:2008, -200°C to +850°C), thermocouples (Fe-CuNi, NiCr-Ni, and others), and 4-20 mA standard signals, with 12 configurable linearizations available to match the specific process sensor in use. A backlit LCD display with plain-text menus simplifies configuration and operation, and a USB interface paired with JUMO’s setup program allows configuration and archiving of device settings without opening the enclosure.

The device mounts on a standard 35 mm DIN rail and provides two SPDT relay outputs – one for pre-alarm (KV) and one for limit alarm, the latter with a fuse cut-out – along with a digital input filter with adjustable filter time constant to reject transient noise on the measured signal. A wide voltage supply range covers AC 110 to 240 V (+10%/-15%) or AC/DC 20 to 30 V, and the device carries IP20 protection with a polycarbonate housing rated UL 94 V0 for flame resistance. An Ex-rated variant (safetyM STB/STW Ex) extends approval into hazardous areas, with intrinsically safe [Ex ia] inputs allowing relevant probes to be connected directly.

Key Features

The JUMO safetyM STB/STW combines certified functional safety architecture with configuration flexibility that makes it a standard choice for thermal process safety protection.

• 1oo2D dual-channel architecture provides safe fault detection per DIN EN 61508 and DIN EN 13849.
• SIL 3 and Performance Level e (PL e) approvals support high-consequence machinery and process safety applications.
• Configurable as a manual-reset safety temperature limiter (STB) or an auto-reset safety temperature monitor (STW).
• Accepts Pt100, Pt1000, thermocouple, and 4-20 mA signal inputs with 12 selectable linearizations.
• A backlit LCD display with plain-text menus and USB-based setup program simplify configuration and archiving.
• Two SPDT relay outputs (pre-alarm and limit alarm with fuse cut-out) support layered alarm escalation.
• A wide voltage supply range (AC 110-240 V or AC/DC 20-30 V) supports diverse electrical infrastructure.
• An Ex-rated variant with intrinsically safe [Ex ia] inputs extends the platform into hazardous area installations.

Industrial Applications

The JUMO safetyM STB/STW is deployed across heat-generating industrial systems, thermal process plants, and machinery subject to the EU Machinery Directive wherever reliable, certified overtemperature protection is required to prevent injury, environmental harm, or damage to production equipment. Typical duties include boiler and furnace overtemperature protection, thermal oil heater safety cutout, and process heating safety interlocks in general industrial and machine building applications.

As the officially authorized partner for JUMO, Seven Star LLC distributes the JUMO safetyM STB/STW to industrial facilities, thermal process plants, and machine builders throughout Oman and the GCC. The safety limiter is a strong fit for thermal process safety systems across the Sohar and Salalah industrial zones, as well as for general industrial and machine building applications across Muscat that require certified, dual-channel overtemperature protection.

Technical Specifications

The table below summarizes the core specifications of the JUMO safetyM STB/STW as supplied by Seven Star LLC.

Call To Action

Seven Star LLC supports the full procurement cycle for the JUMO safetyM STB/STW safety temperature limiter/monitor, from formal RFQ submission to regional warehouse stock availability, technical datasheet delivery, and direct consultation with our instrumentation division on sensor configuration, SIL/PL requirements, and Ex-area approvals for your application. As the authorized partner for JUMO in Oman and the GCC, we ensure every JUMO safetyM STB/STW is delivered with full manufacturer warranty and dependable local technical support. Contact Seven Star LLC today to request a quotation or discuss your thermal process safety requirements.