Overview
Manuals
Principle
Application Features
Features:
- OEM Certified 39" Thermocouple
- Specialized thermocouple used as a critical safety component in gas-fired heating appliances
- It is primarily designed as an original equipment manufacturer (OEM) replacement part
Its primary function is flame sensing; it monitors the ignition flame to ensure a flame is present before the main gas valve remains open. With its specially designed 39-inch lead and M8 threaded nut, it provides the length and secure connection required for a variety of high BTU heater configurations, serving as the first line of defense against unburned gas buildup.
In practical applications, the 125275-01F can be used as an automatic shut-off trigger to protect users from potential gas leaks. If the ignition flame is extinguished due to gas flow or mechanical failure, the thermocouple quickly detects the temperature drop and cuts off the electrical signal to the gas control valve. This robust, copper-clad sensor is designed to withstand the localized high temperatures of the ignition source while maintaining a stable millivolt output, ensuring the heating system operates only under safe and controlled combustion conditions.
The 125275-01F Bently Nevada Thermocouple may still be available for purchase and support from Moore Automated Company beyond End-Of-Life (EOL) by the manufacturer (OEM).
Bently Nevada 125275-01F Thermocouple INFO(Datasheets), Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
The 125275-01F operates based on the Seebeck effect: when heated by the ignition flame, a tiny voltage is generated at the junction of the two different metals at the sensor tip. This heat generates a millivolt (mV) current, which flows through a copper wire to the solenoid coil inside the gas valve, providing enough energy to keep the plunger in the open position under the action of a spring. After the flame goes out, the connection point cools down, the voltage drops to zero, the de-energized coil releases the plunger, and the gas supply is immediately cut off.
Extra-long connection: Its 39-inch (approximately 100 cm) long cable allows for connection from the ignition assembly to the gas control valve of large cabinet heaters, whereas standard 12-inch or 24-inch thermocouple cables are too short.
Safety interlock: Its application is crucial for the Oxygen Depletion Sensor (ODS) ignition assembly. If the oxygen content drops or the flame flickers, the 125275-01F detects a temperature drop and cuts off the gas.
Direct mounting: Designed for equipment such as the Reddy Heater BWH10NLMC and various FMI/DESA luminous firewood systems.
