Textile serves, when applied to Litz wires, act as an optional layer of added mechanical protection for the overall conductor. Serves are particularly effective at protecting the enamel layer on the individual strands of the conductor from abrasion during further processing. The serve acts as a physical barrier between the enamel layer and any contact points that may be present in the wire path of a cutting & terminating operation for the Litz wire.
Similar to the fiberglass braid on braided silicone wire, the serve helps to protect the soft enamel insulation underneath from sharp edges and pinch points in the wire path. However, it’s important to note that textile serves are not intended to act as electrical insulating layers and will not replace electrical insulation where required.
Manufacturing Capabilities
At Rubadue Wire, we have the expertise and equipment to meet your needs for served Litz wires. We can apply serves to:
- Litz conductors as small as 0.015” [0,38mm] in diameter
- Recently expanded capabilities for larger Litz conductors with diameters greater than .340” [8,63mm]
Key Considerations for Your Application
Number of Serve Layers
Litz wire can be supplied with one or two layers of a textile serve for added mechanical strength and protection.
Space Availability
Consider the impact on wire diameter:
- Single nylon serve adds approximately 0.002” (0,051mm)
- Double nylon serve adds approximately 0.004” (0,102mm)
- Other serve materials may have greater impact on the outside diameter
- Available space in a winding may affect the achievable number of turns
Operating Temperature
Nylon serves are commonly used with Class F (155°C) Litz conductors. Higher temperature applications may require alternative materials such as PTFE, Nomex®, or fiberglass.
Serve Material Comparison
| Serve Material | Recommended Max Operating Temp. | Single Serve Diameter Increase | Double Serve Diameter Increase | Solderable | Cost |
|---|---|---|---|---|---|
| Cotton | 105°C | 0.005” | 0.010” | No | Low |
| Silk | 110°C | 0.002” | 0.004” | Yes | High |
| Nylon | 155°C | 0.002” | 0.004” | Yes | Low |
| Polyester | 155°C | 0.004” | 0.008” | Yes | Mid |
| Nomex® | 204°C | 0.003” | 0.006” | No | High |
| PTFE | 260°C | 0.008” | 0.016” | No | High |
| Fiberglass | 260°C | 0.005” – 0.010” | 0.010” – 0.020” | No | High |
Flexibility Considerations
Some stranded Litz conductors may experience reduced flexibility with the addition of a serve. This occurs because:
- The tightly wound serve fibers restrict strand movement
- Strands and rope-lay members can’t easily flatten out when bent
- Effect is particularly noticeable with Type 2 Litz conductors
For applications requiring Type 2 Litz, Rubadue Wire has the expertise to design and manufacture Litz conductors that maximize flexibility for proper winding characteristics.
Certifications
Our single and double nylon serves are recognized by UL in Rubadue’s OBMW2 Magnet Wire – Component file, E190291, and are suitable for use in many UL approved Electrical Insulation Systems.
Need assistance in determining if a textile served Litz construction is appropriate for your application? Contact our knowledgeable sales and engineering teams at sales@rubadue.com or +1(970) 351-6100.
*Trademark Notice: Nomex® is a trademark of DuPont de Nemours, Inc.