Overview
The DURAKOOL AFM20-303-M is a single-pole normally open (SPST-NO) mercury displacement relay designed for heavy-duty industrial switching. Built with mercury wetted contacts, this relay delivers consistent performance across repetitive switching cycles and is manufactured by American Electronic Components under the Durakool brand. The AFM20-303-M is rated for 20A continuous current at 600VAC and features a 120V AC coil, making it suitable for control circuits, motor starters, and power distribution applications.
Key Features
- 1-pole normally open (SPST-NO) contact configuration
- Mercury wetted contacts for superior durability and low contact resistance
- 20A continuous current rating at 600VAC
- 120V AC coil voltage for standard industrial control circuits
- Panel mount design with quick-connect terminals
- Proven reliability in legacy and modern control systems
Technical Specifications
- Manufacturer: American Electronic Components / Durakool
- Part Number: AFM20-303-M
- Contact Configuration: SPST-NO (1 pole normally open)
- Contact Voltage Rating: 600 VAC
- Contact Current Rating: 20 Amperes
- Coil Voltage: 120V AC (50/60 Hz)
- Contact Type: Mercury wetted
- Mounting: Panel mount
- Terminal Type: Quick connect
- Status: Discontinued by manufacturer
Typical Applications
The AFM20-303-M is commonly used in:
- Industrial motor control circuits
- Power distribution switching systems
- Heavy-duty relay logic circuits
- Legacy automation and control systems
- Equipment retrofits and replacements
- Panel-mount switching applications requiring reliable contact closure
Compatibility & Replacements
Compatible With
- Industrial AC control circuits rated for 120V coil voltage
- Panel-mount relay sockets designed for AFM series relays
- Motor starter control systems
- Power distribution and sequencing logic
- Legacy automation equipment (1980s–2000s era)
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. The AFM20-303-M is discontinued; no direct modern replacement exists. Related legacy models in the AFM series (such as AFM20-310-M) may share socket compatibility but have different coil voltages and contact configurations.
Works With
- Panel-mount relay control systems
- Hardwired logic circuits (non-PLC applications)
- AC-powered industrial equipment
- Heavy-duty switching applications requiring high reliability
