1. Product Overview
The SW202 series of contactors is engineered for direct current (DC) loads, specifically for motors found in electric vehicles such as industrial trucks and airport tractors. This unit features double breaking contacts equipped with silver alloy contact tips, which are designed for weld resistance, durability, and superior electrical conductivity.
Figure 1: Albright SW202 Style Reversing Contactor 12V. This image displays the robust construction of the contactor, featuring prominent copper bus bars and multiple terminals for secure electrical connections.
2. Key Features
- Rated Current: 400 Amps
- Coil Voltage: 12V (available in 24V, 36V, 48V, 64V, 72V & 96V options)
- Contact Configuration: Double Pole, Changeover Contacts
- Arc Suppression: Integrated Magnetic Blowouts
- Coil Power: 11 to 15 Watts
- Rated Voltage of Contact Circuit: 6 to 80 Volts DC
- Dielectric Voltage Strength: 50Hz 1000V AC for 1 minute
- Main Contact Volt Drop (at 100A): Not above 80mV
- Operating Time (Make & Break): Greater than 30ms
- Mechanical Life: 100,000 cycles
- Electric Life: 20,000 cycles
- Lug Connector Size: 3/8ths inch
- Coil Connector Size: 1/4 inch spade
- Weight: Approximately 7.0 lbs
3. Technical Specifications
| Specification | Value |
|---|---|
| Connector Type | Screw |
| Current Rating | 400 Amps |
| Mounting Type | Surface Mount |
| Operation Mode | Automatic |
| Wattage | 15 watts |
| Coil Voltage | 12 Volts (DC) |
| Number of Terminals | 3 |
| Material | Copper, Silver |
| Manufacturer | EV Drives |
| Date First Available | April 9, 2014 |
4. Setup and Installation
Proper installation is crucial for the safe and efficient operation of the SW202 contactor. It is recommended that installation be performed by a qualified professional.
4.1 Safety Precautions
- Always disconnect power to the system before installing or servicing the contactor.
- Ensure proper grounding to prevent electrical shock.
- Wear appropriate personal protective equipment (PPE), including insulated gloves and eye protection.
- Verify that the contactor's voltage and current ratings match the application requirements.
4.2 Mounting
The SW202 contactor is designed for surface mounting. Secure the unit firmly to a stable, non-conductive surface using appropriate fasteners. Ensure adequate ventilation around the contactor to prevent overheating.
4.3 Wiring Connections
Refer to the wiring diagram provided with your vehicle or system for specific connection details. General guidelines are as follows:
- Connect the main power cables to the 3/8ths inch lug connectors. Ensure connections are tight and secure to prevent arcing and overheating.
- Connect the control circuit wires to the 1/4 inch spade connectors for the coil. Observe correct polarity for DC coil operation.
- Double-check all connections for correctness and tightness before applying power.
5. Operating Instructions
The Albright SW202 is a reversing contactor, meaning it is designed to control the direction of a DC motor by reversing the polarity of the power supply to the motor. It operates automatically based on the control signals it receives.
5.1 Basic Functionality
- When the appropriate control signal is applied to one of the coils, the contactor will engage, connecting the main power circuit to the motor in a specific polarity.
- When the control signal is shifted to the other coil, the contactor will switch, reversing the polarity to the motor and thus reversing its direction of rotation.
- The magnetic blowouts assist in rapidly extinguishing the arc formed during contact breaking, extending the life of the contacts.
5.2 Operational Considerations
- Ensure the control signals are within the specified coil voltage range (12V DC for this model).
- Avoid rapid, successive switching operations that exceed the contactor's mechanical and electrical life ratings.
- Monitor for unusual noises, excessive heat, or arcing during operation, which may indicate a fault.
6. Maintenance
Regular inspection and maintenance can prolong the life of your SW202 contactor and ensure reliable operation. Always disconnect power before performing any maintenance.
6.1 Routine Checks
- Visual Inspection: Periodically check for signs of physical damage, corrosion, or discoloration on the terminals, contacts, and housing.
- Connection Tightness: Verify that all electrical connections (lug and spade connectors) remain tight. Loose connections can lead to overheating and arcing.
- Cleanliness: Keep the contactor free from dust, dirt, and moisture. Use a dry, non-abrasive cloth for cleaning. Do not use solvents.
6.2 Contact Wear
While the silver alloy contacts are designed for durability, they will eventually wear over time, especially under heavy load or frequent switching. If excessive pitting or material loss is observed on the contacts, replacement of the contactor may be necessary.
7. Troubleshooting
This section provides guidance for common issues. For complex problems, consult a qualified technician.
| Problem | Possible Cause | Solution |
|---|---|---|
| Contactor does not engage (click) | No power to coil; Incorrect coil voltage; Faulty coil; Loose wiring. | Check control circuit power supply; Verify coil voltage matches input; Test coil continuity; Inspect and tighten all coil connections. |
| Contactor engages but motor does not run/reverses incorrectly | No power to main terminals; Incorrect main wiring; Worn main contacts. | Check main power supply; Verify main power wiring against diagram; Inspect main contacts for excessive wear. |
| Contactor overheats | Loose connections; Overcurrent condition; Insufficient ventilation. | Tighten all connections; Verify load current is within contactor rating; Ensure adequate airflow around the unit. |
| Excessive arcing during switching | Worn contacts; Overload condition; Faulty magnetic blowouts. | Inspect contacts for wear; Verify load current; Contactor replacement may be necessary. |
8. Warranty and Support
This product is manufactured by EV Drives. For specific warranty information, please refer to the documentation provided at the time of purchase or contact your vendor. General return policies may apply as per the retailer's terms (e.g., 30-day refund/replacement policy).
For technical assistance or inquiries regarding the Albright SW202 Style Reversing Contactor, please contact EV Drives customer support or your authorized distributor.
Note: Product specifications and features are subject to change without prior notice.