NB123 Fish tank Float Switch – 220volt

What it is: A compact, liquid-level sensor that uses an internal magnetic reed switch triggered by a floating ring to detect water levels in aquariums, sumps, and liquid reservoirs.  

Key Specs:

• Max Switching Voltage: Up to 220V AC / DC (voltage rating, not direct power load capacity).  

• Max Current: Typically 0.5A (low power contact rating, max 10W).  

• Material: Non-toxic, corrosion-resistant plastic (Polypropylene/PP) safe for both freshwater and saltwater fish tanks.  

Key Features: Supports both Normally Open (NO) and Normally Closed (NC) configurations simply by flipping the float ring upside down.

Important Safety Note: Although rated for up to 220V, its low current limit (0.5A) means it should not directly switch high-power 220V mains equipment (like heavy AC water pumps or heaters). Instead, use it as a signal input to a low-voltage relay, microcontroller (Arduino/ESP32), or contactor.

Common Uses: Auto Top-Off (ATO) systems, high/low water level alarms, and dry-run protection for aquarium pumps.