A Reliable Switch for Industrial Control Basic Information
Brand and Model
It is an AC contactor of the SP11 series produced by Shihlin Electric (Taiwan). It is often written as “SP11” in the market, and both notations are interchangeable.
Product Positioning
It is a smallsized industrialgrade AC contactor, suitable for motor control and onoff control of circuits in general power systems.
Origin
Original production in Taiwan; some versions sold in mainland China are domestically assembled. Core Specifications and Parameters
| Parameter Item | Value |
| Rated Current | 12A (under 380V AC3 operating condition) |
| Rated Power | 5.5kW / 7.5HP (at 380V) |
| Maximum Continuous Current | 20-24A |
| Control Coil Voltage | AC 24V/110V/220V/380V; DC 24V |
| Rated Operating Voltage | Up to 660V AC |
| Number of Poles | Standard 3 poles; some special models have 4 poles |
| Auxiliary Contacts | Standard type: 1NO (Normally Open); optional 1NC (Normally Closed) or combined type |
| Mechanical Life | Up to 6 million operations |
| Electrical Life | Approximately 1.2 million operations |
| Protection Class | IP20 (protects against intrusion of solid foreign objects larger than 12mm) |
Product Features and Advantages
1. Multiple Safety Certifications
It has passed international standard certifications such as GB 14048.4, IEC 6094741, UL 508, CSA, TÜV, and CE, ensuring safe use worldwide.
- Flexible Voltage Adaptation
It supports multiple control coil voltages (24V380V), adapting to the needs of power systems in different regions and facilitating global procurement and use. - Reliable Arc Suppression Design
It adopts an automatic arc suppression structure to form a closed arcextinguishing chamber. It has a good arc suppression effect and zero arc flash distance, enhancing operational safety. - Modular Design
Auxiliary contact sets (SP11~P60T series) can be added to increase control flexibility and signal feedback functions, meeting complex control requirements. - Compact Structure
With dimensions of approximately 68mm×30mm×76mm, it saves installation space and is suitable for control cabinets with limited space.
Application Scenarios
1. Motor Control
Start, stop, and forwardreverse control of small and mediumsized threephase asynchronous motors (≤5.5kW).
Used in conjunction with thermal overload relays (such as the THP series) to provide overload protection and form a complete motor starter.
- Industrial Automation Equipment
Power control for various production machinery and processing equipment.
Onoff control of circuits for machine tools, injection molding machines, and other equipment. - Power Systems
Circuit switching in power transmission and distribution control systems.
Centralized control of lighting, air conditioning, and other equipment. - Other Applications
Elevator control systems.
Control of pump equipment.
Control of fans and other occasions requiring frequent startstop operations.
Model Description and Selection Key Points
Standard Models
SP11: Standard type, nonreversible contactor with 1NO auxiliary contact.
S2xP11: Reversible type (double contactor combination), used for forwardreverse control of motors.
SP11T: Integrated model with thermal overload protection function.
Key Parameters for Selection
1. Rated Current: Select based on the load current, ensuring it is ≥ the actual operating current.
2. Coil Voltage: Must match the control circuit voltage (AC/DC and voltage value).
3. Contact Type: Select 1NO, 1NC, or combined type according to control requirements.
4. Operating Environment: Avoid use in humid, corrosive, or hightemperature environments. Installation and Maintenance Recommendations
1. Installation Method
Guide rail mounting (HT35 standard) or screw fixing (M4 screw hole). The inclination of the mounting surface relative to the vertical plane should not exceed 5°.
- Wiring Notes
Main contacts are connected to the load circuit, and auxiliary contacts are connected to the control circuit.
Ensure wiring is secure to avoid heat generation or malfunctions caused by loose connections. - Regular Maintenance
Clean the contact surface and remove oxide layers.
Check if the coil connections are loose.
Ensure the arcextinguishing chamber is undamaged to maintain good arc suppression performance.
Summary
The Shihlin SP11 (SP11) contactor is an industrial control component with reliable performance and complete specifications. With its multiple safety certifications, flexible voltage adaptation, and modular design, it has become an ideal choice in the fields of motor control and industrial automation. When selecting, please choose the appropriate specification and function version based on actual load requirements and control circuit characteristics to ensure stable system operation.
Note: There are counterfeit products in the market. It is recommended to purchase through authorized distributors to ensure quality and aftersales service. Original products have a clear Shihlin logo and complete product parameter labels.
