Watlow TLM-8 Thermal Limit Monitor Type K T/C 100-1205°C 8-Zone Relay

Watlow TLM-8 Thermal Limit Monitor Type K T/C 100-1205°C 8-Zone Relay

The Watlow TLM-8 is an 8-zone thermal limit monitor designed to protect industrial processes from over-temperature conditions. It accepts thermocouple or RTD sensor inputs across multiple zones and triggers relay outputs when a temperature threshold is exceeded, providing a safety shutdown or alarm function independent of the primary process controller. The unit carries UL (Process Control Equipment), FM, and CE certifications.

Specifications & What's Included

• Manufacturer: Watlow
• Model: TLM-8
• Type: Thermal Limit Monitor (over-temperature safety monitor)
• Number of zones: 8
• Sensor type (as configured): Type K Thermocouple (T/C)
• Temperature range: 100 to 1205°C
• Compatible sensor types: RTD, J T/C, K T/C, T T/C, E T/C, R T/C, S T/C, Thermocouple Switch
• Relay outputs: 8 individual relay outputs (TB1); rated 30V AC, 1.00A
• Global relay terminal: TB2
• Rated for copper conductors only
• Sensor input terminals: TB5, positions 1–16
• Control/power terminal: TB6
• Supply voltage: 10.28 Vdc, 400 mA (SEL-V Limited Energy)
• Certifications: UL Listed (Process Control Equipment), FM Approved, CE
• Form factor: DIN rail / panel mount module in aluminum enclosure
• Includes: green PCB terminal connector boards at both sensor and relay ends

Applications

The Watlow TLM-8 is used as a dedicated over-temperature safety device in industrial process heating systems. Unlike a standard temperature controller that regulates process temperature, a thermal limit monitor acts as an independent watchdog — monitoring each zone separately and tripping a relay if any zone exceeds its set limit. This makes it well suited for multi-zone furnaces, kilns, ovens, heat treat systems, plastic processing equipment, and semiconductor thermal processing tools where a single controller failure could cause runaway heating. Watlow's TLM series has been a standard component in North American process heating installations, commonly specified alongside Watlow Series controllers and other DIN-rail mounted process control equipment. The unit's FM approval makes it suitable for use in certain hazardous (classified) locations as well.