Square D 8536SFO1S is a NEMA Size 4 Type S non-reversing motor starter engineered for reliable control of industrial AC motors. Manufactured by Square D (Schneider Electric), this workhorse starter delivers dependable full-voltage motor starting for applications demanding precision and uptime in manufacturing plants, pump stations, and process facilities.
Overview
The 8536SFO1S provides proven motor control in an open, compact form factor. This three-pole, three-phase unit is rated for 135 amperes and operates at 600 volts AC. With thermal overload relay protection built in, the starter safeguards motors against overload conditions while maintaining industry-standard NEMA construction and compliance.
Key Features
- NEMA Size 4 rated for 100 HP at 460/575 VAC or 50 HP at 230 VAC
- Three-pole, three-phase design for AC squirrel cage motor control
- Type S non-reversing configuration with separate coil control circuit
- Thermal melting-alloy overload relay with manual trip for motor protection
- Replaceable control coil available in multiple voltage ratings (110/120V, 24V, etc.)
- 100 kA maximum SCCR (Short Circuit Current Rating) per UL508A
- Open enclosure design allows integration into custom control panels
Technical Specifications
- NEMA Size: 4
- Input Voltage: 600 VAC
- Phase: 3-Phase
- Amperage Rating: 135 A
- Poles: 3
- Starter Type: Type S Non-Reversing Magnetic
- Horsepower Rating: 100 HP @ 460-575V
- Overload Protection: Thermal Melting Alloy Relay
- Dimensions: 12.88″ H × 6.00″ W × 6.50″ D
- Weight: Approximately 20 lbs
- Enclosure Type: Open (no enclosure)
- Series: A
- Certifications: UL Listed, CSA Certified
- Control Coil Options: 110/120 VAC 50/60 Hz, 24 VDC, others available
Typical Applications
- Pump motor starting in water and wastewater treatment plants
- Fan and blower motor control in HVAC systems
- Conveyor and material handling motor control
- Compressor motor soft-starting in industrial facilities
- Machine tool motor control in manufacturing environments
- Panel-mounted motor control systems requiring separate coil voltage
Compatibility & Replacements
Compatible With
- Square D / Schneider Electric control circuits and enclosures
- Standard 600V three-phase motor circuits
- NEMA 4X industrial control panels
- AC squirrel cage induction motors (three-phase, up to 100 HP)
- Auxiliary contact kits and pilot control devices
- Thermal overload relay test blocks and monitoring systems
Replaces / Drop-In Replacement For
- 8536SFO1 (other coil voltage variants)
- Verify compatibility with your system integrator before ordering to ensure coil voltage, control circuit, and mechanical fit match your application.
Works With
- Square D Type S control coils (multiple voltage ratings: 24V, 110V, 120V, 208V, 240V, 480V)
- Standard NEMA motor starters in industrial control systems
- Manual and pushbutton stations for motor starting/stopping
- Auxiliary contacts for interlock and holding circuit logic
- Power monitoring and energy management systems via auxiliary contact outputs
