Overview
The Square D 8501-TO-21 /A is a Class 8501 general-purpose pilot duty relay designed for industrial control circuits and switching applications. Rated for 120VAC with a 1.5A contact rating, this relay is a workhorse in factory automation, HVAC control, and electrical panel circuits. The 8501-TO series belongs to Schneider Electric’s reliable Class 8501 plug-in relay family, engineered for multi-pole switching at voltages up to 240VAC. This used, fully tested unit meets OEM specifications and is suitable for replacement or retrofit installations.
Key Features
- Class 8501 general-purpose relay for standard industrial control
- 120VAC coil voltage with 1.5A pilot duty contact rating
- Plug-in design allows easy installation into standard 8501-series sockets
- Continuous-rated coil for reliable 24/7 operation
- Compact form factor suitable for panel mounting and DIN-rail installations
- Fully tested and verified functional before shipment
Technical Specifications
- Coil Voltage: 120VAC, 60Hz
- Contact Rating (Pilot Duty): 1.5A
- Duty Type: Pilot duty (light-load switching)
- Coil Rating: Continuous-rated
- Mounting: Plug-in socket base
- Class: 8501 (General Purpose)
- Contact Configuration: Multiple poles available (verify with socket type)
- Operating Temperature: Standard industrial range
- Manufacturer: Square D / Schneider Electric
- Condition: Used, tested, fully functional
Typical Applications
The 8501-TO-21 /A is commonly used in:
- Process control circuit switching and sequencing
- Pilot duty loads (low-current indicator lights, solenoids, and coils)
- HVAC and building automation control panels
- Industrial machinery start/stop logic circuits
- Alarm and status signaling circuits
- Retrofit replacements in existing automation systems
Compatibility & Replacements
Compatible With
- Square D 8501 series plug-in relay sockets
- Standard 8501-series mounting bases (NR, KF, and related socket types)
- Industrial control panels rated for 120VAC circuits
- Legacy automation systems using Class 8501 relays
- General industrial control wiring and DIN-rail systems
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator or panel designer before ordering. The 8501-TO-21 /A is a specific type variant within the Class 8501 family; ensure socket compatibility and contact configuration match your application.
Works With
- Square D / Schneider Electric Class 8501 relay ecosystem
- Standard industrial 120VAC control circuits
- PLCs, timers, and contactors using 120VAC relay inputs
- Manual and automated control systems
