Overview
The Control Concepts CI-2120-B is a zero speed switch engineered to monitor rotary motion in shaft-driven process equipment, conveyor systems, and motor-driven machinery. Manufactured in the USA, this cast iron-housed unit provides reliable speed detection across a 24–2000 RPM operating range, triggering protective signals when operating speed deviates from normal.
Key Features
- SPDT (Single Pole, Double Throw) contact configuration for flexible circuit control
- Cast iron housing rated NEMA 4 for industrial environment protection
- Operating range 24–2000 RPM with 14–19 RPM trip point adjustment
- Base mount configuration for stable, concentric shaft alignment
- Detects speed loss, overload slowdown, overspeed, reversal, and mechanical failure
- Low torque requirement (0.0208 ft-lb / 0.0282 Nm) minimizes load on motor bearings
- Available in multiple voltage ratings (125/250/480VAC typical)
Technical Specifications
- Manufacturer: Control Concepts (DAZIC Brand)
- Model: CI-2120-B
- Housing Material: Cast Iron
- Operating Range: 24–2000 RPM
- Trip Point: 14–19 RPM (adjustable)
- Contact Type: SPDT (Single Pole, Double Throw)
- Shaft Diameter: 1/2″ (12.7 mm)
- Mounting Style: Base mount
- Driver Torque Required: 0.0208 ft-lb (0.0282 Nm)
- Temperature Range: -40°F to +250°F (-40°C to +121°C)
- NEMA Rating: NEMA 4
- Dimensions (L × W × H): 6.02″ × 4.25″ × 3.93″ (153 mm × 108 mm × 100 mm)
- Weight: 8 lbs (3.63 kg)
- Typical Voltage Ratings: 125/250/480VAC available
- Maximum Amperage: 10 amps
Typical Applications
The CI-2120-B is widely deployed in:
- Conveyor Systems: Interlocked monitoring of belt speed and drive shaft rotation to halt operation if one component fails or slows
- Pump and Fan Circuits: Detection of impeller/blade stoppage due to mechanical jam or motor failure
- Material Handling Equipment: Speed verification in staging tables, spreaders, and rotating indexers
- Drive Shaft Safety Interlocks: Sensing abnormal speed changes in critical rotating shafts to trigger alarms or cut power to dependent machinery
- Process Monitoring: Integration with PLCs and control stations for real-time speed status feedback
Compatibility & Replacements
Compatible With
- Control circuits rated for 10 amp AC load switching at 125, 250, or 480VAC
- Shaft-mounted drive systems with 1/2″ (12.7 mm) bore or coupling interface
- Industrial PLC systems and alarm logic controllers via SPDT relay output
- Conveyor interlocking systems and safety chains requiring shaft speed monitoring
Replaces / Drop-In Replacement For
- Control Concepts CI-2120-1-B (standard 24–2000 RPM model)
- Previous generation Control Concepts 2100 Series zero speed switches
Works With
- SPDT relay contact output compatible with any AC circuit rated for 10 amps at specified voltage
- Programmable logic controllers (PLCs) via discrete input modules
- Safety relay modules and hardwired interlocking systems
- Standard industrial motor control circuits and contactor coils
- Signal amplifiers and auxiliary relay logic for expanded switching capacity
