Shelly RC Snubber

The Shelly RC Snubber is a small but important device designed to protect your smart home devices, specifically relays like those found in Shelly products, from voltage spikes and interference caused by inductive loads. Here's a breakdown of what it is and why you might need one:

What it is:

An RC snubber is a circuit consisting of a resistor (R) and a capacitor (C) connected in series. It's designed to be connected in parallel with an inductive load, like a motor, solenoid, or transformer.

Why it's needed:

Inductive loads, when switched off, can generate significant voltage spikes. These spikes can damage or shorten the lifespan of relays and other sensitive electronic components in your smart devices. The RC snubber absorbs these voltage spikes, protecting the relay contacts and other circuitry. Think of it like a surge protector, but specifically for inductive kickback.

How it works:

When the inductive load is switched off, the energy stored in the inductor tries to maintain the current flow. This can cause a high voltage spike. The capacitor in the RC snubber charges up during this spike, effectively absorbing the energy. The resistor then discharges the capacitor, preventing it from oscillating and causing further issues.

When you might need one:

You should consider using an RC snubber when switching inductive loads with relays, particularly if you experience any of the following:

• Relay chatter or flickering: The relay contacts might bounce or flicker when switching the inductive load.
• Premature relay failure: Relays might wear out or fail sooner than expected.
• Interference with other devices: Voltage spikes can cause interference with other electronic devices in your home.
• Dimming issues with lights: If you're controlling lights, you might see flickering or inconsistent dimming.
• Motor issues: The motor might not start or stop reliably.