When purchasing a 35kV 600A Class Deadbreak Bushing, the process doesn't end with the bushing body itself. The "devil is in the details"—specifically in the threaded studs and terminals that complete the electrical path. Choosing the wrong accessory can lead to overheating, mechanical failure, or a system that simply won't fit together during a midnight emergency repair.

Here is what you need to know to specify the right components for your Eaton Cooper Power series installation.

1. 600A vs. 900A: It’s All in the Metal

The most critical decision in your procurement process is determining the continuous current requirement.

• The 600A Standard: If your system operates at a standard 600A rating, the Aluminum Threaded Stud (STUD635-A) is the cost-effective, industry-standard choice.

• The 900A Power-Up: If you anticipate load growth or are designing a high-capacity feeder, specify the All-Copper Threaded Stud (STUD635-C). By simply changing the material of this one small component, you increase the bushing’s capacity by 50% (up to 900A continuous).

2. Thread Sizes: Don't Get Stripped

Compatibility is the cornerstone of the IEEE Std 386™ standard, but you must ensure your stud matches your connector.

• Standard Interface: Most 35kV 600A interfaces use a 5/8"-11 UNC thread.

• Custom Requirements: While the documentation focuses on standard threads, always verify if your existing separable connectors (like BOL-T™ or T-OP™ II) require a specific length or a 1" thread for specialized 900A applications. Using the wrong thread pitch or size during installation will result in cross-threading, destroying the bushing's internal contact.

3. The Mounting Hardware: Clamp and Gasket

A bushing is only as good as its seal. When ordering, ensure the following hardware is included or inspected:

• The 4.50" Square Clamp: This stainless steel or plated steel clamp is what applies the even pressure needed to prevent oil leaks.

• Buna-N Gaskets: These are the "lungs" of the seal. Ensure you have fresh gaskets on hand. If you are using FR3™ Bio-fluid, confirm that your gaskets are rated for ester-based fluids to prevent swelling.

4. Part Number Cheat Sheet

To make your procurement easier, here are the common catalog references found in the technical data:

• Bushing Body: 35kV Class Deadbreak (Reference Catalog CA800020EN).

• Aluminum Stud: STUD635-A (For 600A applications).

• Copper Stud: STUD635-C (For 900A applications).

• Installation Instructions: Always request document S800-35-2 for your field crews.

5. Why Standardization Matters

By sticking to the Cooper Power series, you aren't just buying a part; you are buying an ecosystem. These bushings are tested to operate seamlessly with Eaton’s full line of connectors. This reduces the "Product Mixed-Bag" risk where components from different manufacturers might technically fit but haven't been thermally tested as a single unit.

Summary

Specifying the right 35kV bushing requires looking beyond the voltage rating. By matching the stud material to your current needs and ensuring thread compatibility with your connectors, you guarantee a substation that is both high-performing and easy to maintain.