RC Snubber Design Guide for 120 VAC 60 Hz Single-Phase Motors
 
Benefits
Save time designing complex snubber circuits with this design guide, only takes about 45 minutes to design and analyze a new or existing snubber circuit
Have confidence that your snubber is designed for safe, reliable operation with AC mains
Build expertise with design tips and recommended configurations
 
Immediate digital download at purchase. Nineteen pages.
 
Purpose of design guide
Use this design guide to create a functional, and safe, resistor-capacitor (RC) snubber circuit for use with 120 VAC 60 Hz single-phase motors that are controlled by an upstream switching device.
 
Who should use this design guide
This design guide is meant for hobbyists, circuit designers, and engineers who are designing an RC snubber from scratch or analyzing an existing design.
 
Use-case and circuit topology
Use this design guide for RC snubbers that run parallel to the load (i.e., AC motor), both of which are controlled by an upstream switching device (e.g., relay, MOSFET, BJT, or manual switch).
 
Constraints, limitations, and assumptions
Snubber resistor must be between 47 ohms and 120 ohms
Snubber capacitor must be between 0.10 µF to 2.2 µF
AC motor must draw between 0.15 A rms and 4.71 A rms with a power factor of approximately 0.67 (typical for small single-phase AC motors), includes 1/6 HP, 1/8 HP, and 1/10 HP motors
 
How to use the design guide
Follow the instructions which use simple calculations and graphs to analyze and design an RC snubber circuit. Since the process of designing RC snubber circuits is iterative, the worksheet contains three columns labeled “pass” for multiple iterations.
 
Contains nine RC snubber designs that were created using this design guide and cover a range of motor currents that may be used by as-is, or as reference. Component recommendations are provided.