1. Product Overview
These Generisch carbon brushes are designed as high-quality replacement components for electric motors, specifically for the Ferm FKZ-250 N circular saw. Carbon brushes are essential for transmitting electrical current to the motor's commutator, enabling the motor to operate. Over time, carbon brushes wear down and require replacement to maintain optimal motor performance and prevent damage.
2. Compatibility
These carbon brushes are compatible with the following model:
- Ferm FKZ-250 N Circular Saw
They are designed to replace original part numbers such as:
- CB153, CB-153, CB 153
- CB155, CB-155, CB 155
- 181044-0
- 181048-2
3. Specifications
| Dimensions (W x H x L) | 6.5 mm x 13.5 mm x 17 mm (approximately) |
| Version | With automatic shut-off (bussola) |
| Quantity | 2 pieces (1 pair) |
| Manufacturer Part Number | KB-12-1120/27 |
Figure 1: Dimensions of the carbon brushes. The image displays two carbon brushes, each with a spring and a copper wire. Labels indicate the width (B: 13.5 mm), height (H: 6.5 mm), and length (L: 17.0 mm) of the carbon block.
4. Installation and Setup
Replacing carbon brushes requires careful attention to safety and proper procedure. Always refer to your power tool's specific instruction manual for detailed disassembly and reassembly steps.
4.1 Safety Precautions
- Always disconnect the power tool from the electrical outlet before performing any maintenance or part replacement.
- Wear appropriate personal protective equipment (PPE), such as safety glasses.
- Work in a well-lit and clean area.
4.2 Replacement Procedure
- Locate the Carbon Brush Holders: On most circular saws, the carbon brush holders are accessible from the exterior of the motor housing. They are typically secured by screw caps or covers.
- Remove the Old Brushes: Unscrew the brush cap(s) and carefully pull out the old carbon brush and spring assembly. Note the orientation of the brush for correct installation of the new one.
- Inspect the Commutator: While the brushes are out, inspect the motor's commutator (the copper segments on the armature). It should be clean and smooth. If it's excessively grooved or dirty, professional servicing may be required.
- Insert New Brushes: Carefully insert the new carbon brush into the holder, ensuring the copper wire and spring are correctly positioned. The brush should slide in smoothly without force. Ensure the automatic shut-off feature (if present) is correctly aligned.
- Secure the Brush Caps: Screw the brush cap(s) back into place, tightening them securely but without over-tightening.
- Test the Tool: Reconnect the power tool to the electrical outlet. Briefly run the tool at a low speed to allow the new brushes to seat properly. Initial sparking is normal but should reduce quickly. If excessive sparking or unusual noise persists, disconnect power and re-check the installation.
5. Maintenance
Regular inspection of carbon brushes can extend the life of your power tool. Check brushes periodically, especially if the tool experiences heavy use or shows signs of reduced performance.
- Visual Inspection: Look for signs of wear, such as brushes worn down to approximately one-quarter of their original length.
- Cleanliness: Ensure the brush holders and commutator are free from dust and debris.
- Replacement: Replace both carbon brushes at the same time, even if only one appears significantly worn, to ensure balanced motor operation.
6. Troubleshooting
If your power tool exhibits issues after carbon brush replacement or during operation, consider the following:
| Symptom | Possible Cause / Solution |
|---|---|
| Excessive Sparking at Commutator | New brushes need to seat (run tool briefly). Brushes incorrectly installed. Commutator is dirty or damaged. |
| Motor Runs Intermittently or Not at All | Brushes are worn out (if not new). Brushes are stuck in holders. Incorrect brush size. Power supply issue. |
| Reduced Motor Power / Speed | Brushes are worn or not making good contact. Commutator is dirty. |
| Unusual Noise or Burning Smell | Brushes are incorrectly installed or damaged. Motor overheating. Discontinue use immediately and seek professional service. |
If troubleshooting steps do not resolve the issue, consult a qualified technician or the tool manufacturer's support.
7. Warranty and Support
These carbon brushes are aftermarket replacement parts. For specific warranty information regarding these brushes, please refer to the seller's terms and conditions at the time of purchase. For support related to your Ferm FKZ-250 N circular saw, please contact the original manufacturer of the tool.