Danfoss 117u4126 Starting Relay Hst

Product Description

The Danfoss 117U4126 is a starting relay designed for use with hermetic compressors in refrigeration and HVAC applications. Danfoss manufactures this component as part of their HST relay series, which stands for Hermetic Starting Technology. Starting relays play a critical role in single-phase compressor operation. They help the compressor motor reach full running speed by briefly engaging the start winding during motor startup. Once the compressor reaches operating speed, the relay disconnects the start winding to prevent overheating and motor damage.

HVAC technicians and refrigeration service professionals rely on starting relays when diagnosing and repairing compressor startup failures. A faulty starting relay is one of the most common reasons a compressor hums but fails to start. Replacing the relay with a direct OEM equivalent like the Danfoss 117U4126 ensures proper electrical timing and compatibility with the compressor motor specifications.

The HST relay design from Danfoss is engineered to match the starting torque and current characteristics of specific compressor models. Using a correctly matched relay protects the compressor from hard starts, reduces electrical stress, and extends equipment service life. This relay is suitable for use in light commercial refrigeration systems, residential and light commercial air conditioning units, and other sealed compressor applications where single-phase motors require external starting assistance. Always verify compatibility with the compressor model before installation to ensure correct current ratings and terminal configuration.

• OEM Danfoss starting relay for hermetic compressor applications
• Designed to engage and release the start winding during single-phase motor startup cycles
• Helps prevent hard starts, motor overheating, and premature compressor failure

Product Highlights

The Danfoss 117U4126 HST starting relay is a direct OEM replacement component for hermetic compressors in refrigeration and HVAC systems. It provides reliable start winding control to protect compressor motors and support consistent equipment operation.

Product Information

Standard Information

• Brand: DANFOSS
• Manufacturer Part Number: 117U4126

Technical Specifications

• Component Type: Starting Relay
• Series: HST (Hermetic Starting Technology)
• Application: Single-phase hermetic compressors
• Compatible Systems: Refrigeration and HVAC compressor units