Overview
The Square D 9999-SX7 is a Class 9999 electrical interlock engineered for high-reliability motor control and equipment interlocking applications. This normally closed (N.C.) contact block carries an AC rating of NEMA A600, making it suitable for use in harsh industrial environments where safety interlocks and circuit protection are critical. Series B construction provides proven durability and compatibility with Square D motor starters and control equipment.
Key Features
- Class 9999 electrical interlock with normally closed (N.C.) contact configuration
- NEMA A600 AC voltage rating for reliable operation in standard industrial settings
- Series B construction ensures compatibility with legacy and current Square D equipment
- Compact Type SX-7 form factor fits standard control enclosures
- Tested and fully functional used unit, ready for immediate deployment
Technical Specifications
Specifications verified from manufacturer documentation and industrial surplus distributors:
| Part Number | 9999-SX7 (Series B) |
| Manufacturer | Square D (Schneider Electric) |
| Class | 9999 |
| Type | SX-7 |
| Series | B |
| Contact Type | Normally Closed (N.C.) |
| Voltage Rating | NEMA A600 (AC) |
| Typical Current Rating | 10A |
| Standard Compliance | IEC 947-5-1 |
| Condition | Used, Tested |
Typical Applications
- Motor starter interlocking and safety control circuits
- Equipment gate and guard interlocks
- Drive transmission and clutch engagement control
- Dual-motor coordination where synchronized operation is required
- Replacement blocks for existing Square D motor control centers (MCCs)
Compatibility & Replacements
Compatible With
- Square D motor starters and motor control centers (MCCs)
- Square D Class 8501 contactors and Class 9999 interlock systems
- IEC 947-5-1 compliant control circuits rated up to NEMA A600
- Standard 24VDC and 110/120VAC control signal wiring
Replaces / Drop-In Replacement For
- Worn or failed Square D 9999-SX7 Series A and earlier revision interlocks
- Other NEMA A600-rated normally closed interlocks in equivalent applications
- Verify specific application compatibility with your system integrator before ordering
Works With
- Square D Studio and PowerLogic software for MCC diagnostics
- Motor control relay logic and hardwired control circuits
- IEC 947-5-1 auxiliary contact standards
- Analog and digital control signal conditioning
