ESD safety practice: For a conductive (ESD-safe) workbench, what is the best and correct ground reference to connect to for safe static discharge control?

Introduction / Context:
Electrostatic discharge (ESD) control requires all conductive surfaces, wrist straps, and tools to share a common reference to earth ground. A properly grounded ESD workbench minimizes potential differences that can damage sensitive components.

Given Data / Assumptions:

• The facility provides three-prong outlets with a verified safety ground.
• Bench mats and wrist straps include ground leads with resistors (typically 1 megaohm).
• Goal is a reliable, consistent earth reference for dissipating static safely.

Concept / Approach:

The recommended ground for ESD benches is the verified earth/safety ground provided by the building’s AC outlet ground pin or a dedicated earth ground point. Connecting to another device’s chassis can create ground loops or float if that device is not properly grounded. Vague or misspelled options such as “Ground to bend” are not recognized standards. The AC outlet ground (tested and verified) is the correct, code-compliant reference.

Step-by-Step Solution:

Verification / Alternative check:

Use a continuity/ground monitor or ESD workstation tester to confirm proper grounding and resistance. Observe reduced ESD incidents and stable handling for ICs.

Why Other Options Are Wrong:

• Ground to bend: Not a recognized or meaningful standard connection.
• To another device: Risky; the other device may be floating or poorly grounded.
• Chassis ground: Only acceptable if the chassis is verified earth-grounded; the safest and intended reference is the AC outlet earth ground.
• None of the above: Incorrect because the AC outlet ground is correct.

Common Pitfalls:

Using painted screws with poor conductivity; bypassing the series resistor; failing to routinely check ground integrity.

Final Answer:

AC outlet