Bearing Thermocouple Assemblies for Rotating Equipment

Case Style Reference

Start with the bearing housing and case style, then select the thermocouple type and lead construction. Dimensions are case dimensions. Wire sizes are AWG.

Decision path

• Match case style to bore, contact point, and exit clearance.
• Select Type E, J, K, or T around the existing input or plant standard.
• Use single or dual construction where the case style supports it.
• Choose stainless first, with copper contact options where needed.
• Confirm lead protection, armor, vibration, oil exposure, and routing constraints.

Bearing Thermocouple Contact and Lead Protection

Bearing thermocouples focus on localized bearing contact, protected lead routing, insertion depth, and machine-protection integration. Stainless contact styles come first, with copper contact options available where higher thermal conductivity is useful.

Bearing Thermocouple Model Selection

Stainless Contact Bearing Thermocouple

The standard bearing thermocouple starting point is a stainless contact style for rugged bearing housing measurement, mechanical durability, and corrosion resistance around motors, turbines, turbo machinery, pumps, fans, gearboxes, and driven equipment.

For turbine and turbo machinery bearings, BTC assemblies are used when the protection loop, legacy instrumentation, or response requirement favors thermocouple input. Case geometry, contact depth, lead exit, and armor should be selected around the bearing housing so the sensor protects the machine without interfering with service access.

Copper Contact Bearing Thermocouple

Copper contact styles are available when the application benefits from higher thermal conductivity at the bearing measurement point. Copper should be positioned as the secondary option after stainless, not as the default construction.

Mounting and Retention Options

Bearing thermocouples can be configured around the housing bore, contact depth, lead protection, and retention method. Bayonet and spring-loaded hardware are useful for certain fixed-depth or repeatable-contact installations, but many bearing sensors use other contact and retention styles.

Need RTD-Based Bearing Monitoring?

For machine protection loops and applications that prefer Pt100 stability over thermocouple response, specify a BRTD Bearing RTD as the RTD counterpart.

Application Matrix

• Electric motors using bearing thermocouples for localized winding-adjacent or bearing-point temperature monitoring
• Steam turbine, gas turbine, and turbo machinery bearing points tied into alarm or shutdown systems
• Gearboxes and reducers where contact depth, lead protection, and service access drive the sensor configuration
• Pump and fan bearings using stainless contact styles first, with copper contact options where faster thermal transfer is desired
• Rotating equipment where thermocouple response is preferred over RTD stability