White-rodgers 90-63 Potential Relay 170 Vac 50/60 Hz

Product Description

The WHITE-RODGERS 90-63 is a potential relay designed to assist single-phase motor starting in refrigeration and air conditioning compressor applications. Operating on a 170 VAC coil at 50/60 Hz, it monitors back-EMF voltage across the start winding to disconnect the start capacitor once the motor reaches sufficient speed. The coil pickup range is 140 to 153 VAC, with a maximum dropout voltage of 65 VAC. DC coil resistance measures 1,399 ohms, with a nominal operating load of 5 VA and an inrush of 10 VA at 29 milliamps. Licensed HVAC technicians and refrigeration mechanics are the primary installers of this component.

This potential relay is used in residential and light commercial HVAC and refrigeration systems where single-phase hermetic or semi-hermetic compressors require external start assistance. It is typically installed in systems that use a separate start capacitor and run capacitor configuration. The relay engages during compressor startup and drops out the start capacitor once back-EMF in the start winding rises to the pickup threshold, protecting the capacitor and motor windings from prolonged start-winding energization.

Key Features

• 170 VAC coil voltage rated for 50/60 Hz operation
• Pickup range of 140 to 153 VAC for reliable start-capacitor switching
• Maximum dropout voltage of 65 VAC prevents premature re-engagement
• 1,399 ohms DC coil resistance for stable electrical characteristics
• Low nominal draw of 5 VA with 10 VA inrush rating
• Type 128000 design for compatibility with common compressor starting circuits

Compatibility

Designed as an OEM-style replacement potential relay for single-phase hermetic compressor applications in residential and light commercial refrigeration and air conditioning systems.

Installation Notes

Installation should be performed by a licensed HVAC or refrigeration technician. Disconnect and lock out all power to the unit before handling the relay or associated capacitors. Discharge the start and run capacitors fully before making any wiring connections, as stored charge can cause serious injury. Verify coil voltage and pickup range match the compressor manufacturer specifications before installation.

Technical Specifications

• Coil Voltage: 170 VAC
• Frequency: 50/60 Hz
• Pickup Range: 140 to 153 VAC
• Maximum Dropout Voltage: 65 VAC
• DC Coil Resistance: 1,399 ohms
• Nominal Operating Load: 5 VA
• Inrush Load: 10 VA
• Current Draw: 29 milliamps

Standard Information

• Brand: WHITE-RODGERS
• Manufacturer Part Number: 90-63