750659-1 — Overtemperature Switch Repair & Overhaul

Component Overview

An overtemperature switch is a thermally actuated sensing device that signals or trips a protective circuit when monitored air, duct, or component temperature exceeds a preset threshold. Within the sensors and switches domain, it protects pneumatic, bleed-air, and conditioned-air systems by detecting duct overheat or leak conditions and triggering shutoff, warning, or isolation logic. The switch typically uses a bimetallic element, gas-filled bellows, or eutectic sensor that mechanically actuates electrical contacts at the set point. Repair and overhaul are driven by contact pitting, erosion, and welding from switching cycles, calibration drift of the actuation setpoint, bimetal or bellows fatigue and creep, seal and housing degradation under repeated thermal cycling, corrosion, and electrical terminal and insulation deterioration that cause nuisance trips or failure to actuate at the required temperature.

Aircraft Application

750659-1 is used across multiple aircraft platforms. Contact QTC with your aircraft type and we'll confirm applicability and repair scope.

Our Repair Capability

QTC repairs and overhauls 750659-1 to the original manufacturer's specifications under our FAA and EASA Part 145 approvals. Our team — including former OEM sensors & switches engineers — performs teardown, inspection, cleaning, component replacement, functional testing, and certification, returning a serviceable unit with the appropriate airworthiness release. We also develop repairs for rejected and beyond-economic-repair (BER) hardware.

View Temperature Sensors & Switches capability →

Related Parts

Other overtemperature switch part numbers we repair — view all Overtemperature Switch parts →

Frequently Asked Questions