Schneider Electric B6.25 Thermal Overload Relay

Description:

The Square D B6.25 Thermal Overload Relay Heater Element Unit is a calibrated thermal protection component used in motor starter systems to protect electric motors from sustained overload conditions. It operates by heating a bimetallic strip inside the overload relay assembly, triggering a trip mechanism when current exceeds the rated range over time.

Applications:

The Square D B6.25 heater element is used in Square D motor starters and thermal overload relay assemblies for industrial motors, including conveyor systems, pumps, compressors, HVAC equipment, and manufacturing machinery. It is commonly installed in motor control centers (MCCs) and OEM control panels where precise motor overload protection is required based on motor full-load current calibration.

Technical Specifications:

• Manufacturer: Square D (Schneider Electric)
• Model: B6.25
• Product Type: Thermal Overload Relay Heater Element Unit
• Full Load Current Range: 3.98 – 4.89 A
• Trip Class: Class 20 (typical for thermal units)
• Operating Principle: Melting alloy / bimetal thermal response
• Mounting Type: Plug-in heater element (overload relay base)
• Function: Motor overload protection via time-delay thermal tripping
• Compatibility: Square D Type B / Class 9065 overload relay systems
• Application Environment: Industrial motor control systems and MCC assemblies

Common Replacements:

• Square D B6.90 Thermal Heater Element
• Schneider Electric LRD Series Thermal Units
• Siemens 3RU11 Thermal Overload Heater Elements