Overview
The Square D 8536SFO1S is a heavy-duty NEMA Size 4 motor starter contactor designed for controlling three-phase AC squirrel-cage motors in industrial and commercial automation applications. This Type S magnetic starter provides reliable full-voltage starting and stopping with a 135-amp continuous rating and supports motors up to 100 horsepower at 460/575 VAC. The separate control unit design (Form S) offers flexibility for custom control panel integration.
Key Features
- NEMA Size 4, non-reversing magnetic starter with 3-pole configuration
- 135-amp continuous rating; supports 40 HP @ 200V, 50 HP @ 230V, 100 HP @ 460/575V
- Open-style enclosure for surface-mount or panel integration
- Replaceable coil design with 110/120 VAC control voltage standard (other coil voltages available)
- Built-in thermal overload relay units for motor overcurrent protection
- Up to 100 kA short-circuit current rating (SCCR) per UL508A standards
Technical Specifications
The 8536SFO1S delivers proven performance in demanding industrial environments with class-leading electrical ratings and modular construction for field serviceability.
Typical Applications
- Pump and compressor motor control in water treatment and HVAC systems
- Manufacturing plant machinery and assembly line motor starters
- Industrial fan and blower control
- General-purpose three-phase motor starting in production facilities
- Replacement upgrading of older or failed NEMA motor control units
Compatibility & Replacements
Compatible With
- Square D Class 9001 and 9007 push-button stations for control circuits
- Standard 3-phase AC motor loads rated 40–100 HP (voltage-dependent)
- Industrial control panels and electrical enclosures rated NEMA 1 and above
- Standard DIN rail and surface-mount motor control centers
- Thermal overload protection systems for AC motors
Replaces / Drop-In Replacement For
- Other Square D 8536SFO1 variants with different coil voltages (8536SFO1V03, 8536SFO1V06, etc.)
- Older Square D Type S NEMA 4 starters in equivalent size and rating
- IEC-rated equivalents in comparable horsepower and amperage classes
Works With
- Standard 50/60 Hz power supplies with 110/120 VAC coil control
- Mechanical push-button and electromechanical control devices
- Thermal overload relays (integral or external configuration)
- No PLC or fieldbus integration required—direct hardwired control compatible
