Siemens Industrial Controls 3UB81334GW2 Solid State Overload Relay - ESP200 25-100A 3-Phase

The Siemens 3UB81334GW2 is an ESP200 series solid-state overload relay designed for comprehensive motor protection in single-phase and polyphase motor applications. This Frame Size B relay provides adjustable overcurrent protection from 25 to 100 amps for 3-phase systems, eliminating the need for traditional heater elements.

Key Features:

• Adjustable current range: 25 to 100 amps for Frame Size B applications
• Field-selectable trip class (5, 10, 20, or 30) via DIP switches for light, normal, and heavy starting conditions
• 1NO-1NC contact configuration with B600/R300 contact rating
• Manual and automatic reset functionality with 3-minute automatic reset delay
• Phase loss protection trips in less than 3 seconds to prevent motor burnout
• Phase unbalance and ground fault protection (60% of motor current)
• Self-powered design requires no external power source
• Thermal memory prevents motor restart while still hot
• Screw terminal connections with removable terminal blocks
• Direct mounting and stand-alone installation options

Advanced Protection:

• Conformally coated circuit board resists environmental conditions
• Wide operating temperature range: -25°C to 60°C (-13°F to 140°F)
• Repeat accuracy less than 1% for precise settings and reduced nuisance tripping
• Self-protected in short circuit conditions when used with proper fuses
• Test button verifies complete electronic function and trip mechanism
• Trip indicator provides visible confirmation of overload condition

This solid-state overload relay offers superior reliability compared to traditional bimetal overloads, with no heaters to replace after short circuits. The ambient-insensitive design and selectable trip classes make it ideal for motor protection applications requiring flexibility and precision.