Covers high-voltage and high-power testing in laboratories, shops, substations and in the field on transmission and distribution lines and equipment, but only testing with interim measurements, not continuous measurement such as routine metering, relaying or ordinary line work (routine phasing-out and no-voltage checks by qualified employees are excluded). The employer establishes and enforces work practices protecting each worker at all temporary and permanent test areas, covering at least safeguarding of test areas, grounding, safe handling of control and measuring circuits, and a means for periodic safety checks at field test sites. Employees are trained in safe work practices when first assigned to a test area, with retraining under 1926.950(b). Test areas are safeguarded to control access to equipment or apparatus that could become energized directly or by induction and to prevent accidental contact. Permanent test areas are guarded by walls, fences or other barriers. In field or temporary sites without permanent fences and gates, unauthorized entry is prevented by distinctively colored safety tape about waist high with safety signs, an equivalent barrier, or test observers who can monitor the whole area; these safeguards are removed once no longer needed. The employer establishes and implements grounding practices: any conductive part the test operator can reach stays at ground potential during high-voltage operation, and ungrounded terminals are treated as energized until shown otherwise. Visible grounds are applied automatically, or manually with properly insulated tools, after deenergizing and before work on the circuit or apparatus, with common grounds solidly connected. High-power testing needs an isolated ground-return conductor system unless distance from the source makes it impossible and step and touch potentials are controlled. An alternative clearly indicated ground may replace the cord's equipment grounding conductor where that would be more hazardous or spoil measurements, if the employer shows equivalent protection. On entry after deenergizing, grounds go on the high-voltage and other exposed terminals; high-capacitance items are first discharged through a resistor sized for the stored energy, and direct grounds applied once stored energy is safe. Test trailer or vehicle chassis are grounded and employees protected against touch potentials by bonding, insulation or isolation. Control wiring, meter connections, test leads and cables leaving a test area run in grounded metallic sheaths ending in grounded metallic enclosures, or equivalent precautions. Instruments with accessible terminals are isolated from personnel; metal compartments with viewing windows need interlocks that cut power when opened. Temporary wiring is protected, and signal, control, ground and power cables kept apart as far as possible. A test observer able to immediately deenergize test circuits is present whenever an employee is in the test area during testing. At the start of each series of tests, the test operator in charge conducts a routine safety check verifying barriers and safeguards, test status signals if used, clearly marked emergency test-power disconnects, identifiable ground connections, required PPE, and cable separation.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.