Electrician's Licensing Practice Exam

What type of clamp is needed to properly connect number 4 copper to a ground rod?

1. Direct burial clamp

2. Wire nut connector

3. Screw terminal connector

4. Compression fitting

The correct answer is: Direct burial clamp

A direct burial clamp is necessary when connecting number 4 copper wire to a ground rod because it is specifically designed to withstand underground conditions while providing a secure and reliable connection. These clamps are constructed of materials that resist corrosion and are capable of handling the environmental factors present in soil, such as moisture and varying temperatures. The direct burial clamp provides a strong mechanical and electrical bond that ensures effective grounding, which is crucial for both safety and compliance with electrical codes. The other options, like wire nut connectors and screw terminal connectors, are not suitable for direct burial applications, as they are designed for different types of electrical connections above ground. Similarly, compression fittings are used primarily for joining conduit or tubing, and would not provide the appropriate connection for grounding purposes.