Danfoss 117U6021 Starting Relay

The Danfoss 117U1021 Starting Relay is a critical electronic component designed for hermetic compressors, specifically within the Danfoss FR and SC series. This 117U1021 relay replaced 117U1001 and functions as a current-operated switch to manage the start winding circuit during the initial torque phase. Engineered for 115V 50/60Hz applications, this start relay ensures precise cut-out timing to prevent motor overheating and winding failure. When diagnosing refrigeration compressor starting issues, technicians should verify the resistance across the coil and contacts to ensure proper continuity. This genuine OEM part is essential for maintaining the LST (Low Starting Torque) configuration requirements of residential and light commercial cooling systems. Proper integration of this relay facilitates reliable motor ignition, reducing mechanical stress on the compressor during high-ambient load conditions.

• OEM Compatibility: Exact replacement for Danfoss 117U1001 and compatible with various FR, SC, and TL compressor models.
• Voltage Regulation: Rated for stable operation on 115B circuits, handling the high inrush current typical of startup cycles.
• Thermal Protection: Built to withstand the rigorous duty cycles of hermetic refrigeration systems.
• Direct Plugin Design: Features standard spade terminal configurations for rapid field replacement and secure electrical connections.

Is the Danfoss 117U1021 interchangeable with the 117U6021?
No. While they appear similar, the 117U1021 is calibrated for specific bridge and coil resistance values distinct from the 6021 series. Always verify the compressor model and voltage requirements before installation.

What are the symptoms of a failing starting relay?
Common indicators include the compressor "clicking" but failing to start, tripped circuit breakers, or the motor humming briefly before the thermal overload protector cuts power.

Can this relay be used with a start capacitor?
This specific relay is typically utilized in RSIR (Resistive Start Inductive Run) setups. If your system requires high starting torque (HST), ensure the relay is paired with the manufacturer-specified start capacitor to avoid damaging the motor windings.

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.