Siemens Industrial Controls 3UB81334GW2 Relay

The Siemens 3UB81334GW2 is a high-performance ESP200 electronic overload relay designed for precise motor protection in demanding industrial environments. This solid state overload relay features a wide current adjustment range of 25-100 Amps, making it a versatile solution for NEMA Size 2 and Size 3 starters. Unlike standard bimetallic options, the Siemens ESP200 utilizes advanced self-powered electronics to provide superior accuracy and a 4:1 adjustment ratio, effectively reducing inventory requirements by replacing multiple heaters with a single unit. Designed for 3-phase motor protection, this unit offers field-selectable trip classes (5, 10, 20, or 30) via integrated DIP switches, allowing you to tailor protection for light, normal, or heavy starting loads. The 3UB81334GW2 also incorporates critical safeguards including phase loss protection, phase unbalance detection, and ground fault protection to prevent catastrophic motor failure and minimize unscheduled downtime for your clients.

• Selectable Trip Classes: Field-adjustable settings (Class 5 to 30) provide optimal protection for various duty cycles without changing hardware.
• Enhanced Connectivity: Features 1NO-1NC auxiliary contacts (B600/R300 rating) for seamless integration into control circuits and signaling systems.
• Flexible Reset Modes: Supports manual, automatic, and remote reset capabilities, offering flexibility for both localized and centralized control setups.
• Rugged Reliability: Constructed with conformally coated circuit boards to resist moisture, dust, and harsh environmental conditions common in HVACR applications.
• No Heaters Required: Eliminates the need for traditional thermal heaters, reducing installation time and lowering the total cost of ownership.

How does this relay handle phase imbalance?
The Siemens 3UB81334GW2 utilizes electronic sensing to detect phase unbalance. If an imbalance is detected, the unit trips based on the selected trip class to prevent excessive temperature rise in the 3-phase motor windings.

What is the reset time for the automatic setting?
In automatic reset mode, the relay typically permits a 3-minute cooling period after a trip event. This ensures the motor has reached a safe temperature before re-starting, preventing thermal stress on the insulation.

Can this be used for single-phase applications?
While optimized for 3-phase systems, this solid state relay can be used for single-phase motors by wiring the poles in series to ensure all sensing paths detect current flow, preventing a false phase-loss trip.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.