Schneider Electric B3.70 Thermal Overload Relay

Description:

The Square D B3.70 Thermal Overload Relay Heater Element Unit is a calibrated motor protection component used in Square D Type B thermal overload relay systems. It provides overload protection by converting motor current into heat, which actuates a melting alloy or bimetal mechanism to trip the relay during sustained overcurrent conditions.

Applications:

The Square D B3.70 heater element is used in Square D motor starters and thermal overload relay assemblies for industrial motor protection in conveyor systems, pumps, compressors, HVAC equipment, and manufacturing machinery. It is commonly installed in motor control centers (MCCs), OEM panels, and industrial automation systems where precise thermal protection is required based on motor full-load current ratings.

Technical Specifications:

• Manufacturer: Square D (Schneider Electric)
• Model: B3.70
• Product Type: Thermal Overload Relay Heater Element Unit
• Full Load Current Range: 2.62 – 2.99 A (SuperBreakers)
• Trip Class: Class 20 thermal protection system
• Overload Type: Melting alloy / bimetal thermal sensing element
• Mounting Type: Plug-in heater element for overload relay base
• Function: Motor overload protection via time-delayed thermal trip mechanism
• Compatibility: Square D Type B / Type S overload relay frames
• Application Environment: Industrial motor control systems and MCC assemblies

Common Replacements:

• Square D B3.71 Thermal Heater Element
• Schneider Electric LRD Series Thermal Units
• Siemens 3RU11 Thermal Overload Heater Elements