Gefran 1250L Limit Indicator & Alarm Unit
The Gefran 1250L is an alarm limit indicator (48×96 mm, 1/8 DIN) designed for independent overtemperature monitoring in industrial process environments. This device is not a PID controller; it functions strictly as a limit instrument, with a retained alarm output that remains latched until reset by operator action, digital input, or via RS485 interface.
Measurement Inputs
Universal input supports TC types J, K, R, S, T, C, D, B, E, L, U, G, N, Pt20Rh-Pt40Rh, RTD Pt100/JPt100, IR sensors, and linear signals (0–60 mV, 0–1 V, 0–5 V, 0–10 V, 0/4–20 mA). Scalable range from -1999 to 9999, with sampling intervals selectable at 60 or 120 ms.
Alarm Outputs & Diagnostics
Up to 4 alarm functions assignable to relay outputs (NO 5 A / 250 Vac) or analog retransmission (0–10 V, 0/4–20 mA, 12 bit). Alarms configurable as maximum, minimum, symmetric, absolute, or relative, with memory, startup inhibit, and reset via button or contact input.
Operation & Maintenance
Front panel features LCD with PV, SV, F display, 11-segment bargraph for AL1 deviation, and reset key. The unit logs alarm activation count and total alarm duration, supporting maintenance planning and assessment of furnace or process wear.
Typical Applications
- Independent high-limit alarm in industrial furnaces
- Thermal zone monitoring in extruders, presses, dryers
- Temperature supervision with manual acknowledge
- PV retransmission to PLC, recorder, or SCADA
- Applications requiring alarm trip logging
Operating Conditions & Standards
Power supply 100–240 Vac/Vdc or 20–27 Vac/Vdc, max 10 W. Operating temperature -10…+55 °C. Front panel IP65. Installation category II, pollution degree 2. UKCA declaration per EN 63000, EN 61326-1, EN 61010-1. FM Approvals classifies 650L/1250L as temperature limit switches.