Overview
The Siemens 3UA5800-2E is a delayed thermal overload relay engineered for protecting circuits from motor overloads in industrial control systems. This bimetal-based relay provides a time-delay response to thermal overload conditions, distinguishing momentary inrush current from sustained overcurrent faults. Commonly paired with Siemens 3TF contactors and motor starters, the 3UA5800-2E integrates seamlessly into modular starter assemblies.
Key Features
- Bimetal thermal sensing — Reliable, time-delayed trip response to sustained overload conditions
- 25–40A adjustable range — Precise current selection across the band to match motor FLA
- Dual contact outputs — 1 Normally Open (N.O.) + 1 Normally Closed (N.C.) for signaling and shutoff logic
- On/Off indicator — Visual status feedback to confirm relay state at a glance
- Plug-in design — Direct replacement and field interchangeability with 3UA series relays
- 600VAC rated — Compatible with standard three-phase and single-phase industrial circuits
Technical Specifications
The relay meets legacy Siemens standards and is suitable for retrofit and replacement applications where established starter lineups require plug-in overload modules.
Typical Applications
- Three-phase motor soft-start protection in pumps, compressors, and conveyor drives
- Single-phase motor branch circuits in HVAC and refrigeration equipment
- Integrated protection in modular contactor assemblies
- Panel-mount and field-installed replacement in legacy control systems
Compatibility & Replacements
The 3UA5800-2E is a plug-in module for Siemens 3TF contactors. Original equipment starters may include this relay factory-installed or shipped separately for field installation. Aftermarket thermal overload relays with matching 25–40A current bands and identical contact configurations serve as functional replacements. Always verify contactor series and terminal pin-outs before substituting alternative overload modules.
