Employees should be instructed to be alert at all times when they are working near exposed energized parts where unexpected electrical hazards may exist.

2.13.4.5 ILLUMINATION

Adequate illumination shall be provided before workers are allowed to enter spaces containing exposed energized parts.

2.13.4.6 SYSTEMS UNDER LOAD

Electrical equipment intended to switch current shall have a rating sufficient for the current. Manual switches and disconnects, taps, terminators, and nonenclosed switches shall not be operated while under load, unless the devices are rated as load-break type and are so marked.

2.13.4.7 WORKING WITH TEST INSTRUMENTS AND EQUIPMENT

Sometimes it becomes necessary to check the continuity of power circuits, control circuits, etc., by using a particular testing instrument designed for the testing involved. The voltage device used shall be rated for the application. Proximity testers and solenoid-type devices should not be used to test for the absence of AC voltage because they have a lower voltage (usually in the range of 50 to 110 volts) below which they will not detect voltage, even if it is present. Also, these testers will not detect DC voltage or detect AC voltage in a cable that is shielded. They are very useful in certain applications such as finding cables that go through a panel but do not terminate in the panel. However, it should be noted that just because a proximity tester does not detect voltage does not mean that the equipment or device is actually deenergized. The absence of voltage can only be verified with a voltmeter rated for the application.

Voltmeters, both analog and digital, are designed for a number of applications from appliance troubleshooting to power system testing. The type of voltmeter used depends on where in the power system you are using the meter. The user must read and understand the manufacturers' instructions on the use and application of the voltmeter. When a multi-function, multi-scale meter is used, it is important for the user to select the function and scale necessary for the task being performed in order to avoid damage or destruction of the meter and injury to the employee. See ANSUISA S82.01, S82.02, S83.03, International Electrotechnical Commission (IEC) 1010-1, and UL 1244 for more information on the application and ratings of voltmeters.

The following should apply when working with test instruments and equipment on energized circuits.

2.13.4.7.1 QUALIFIED EMPLOYEES

Only qualified workers who are knowledgeable and have been trained to work safely with test instruments and equipment on energized circuits shall be permitted to perform testing work on electrical circuits or equipment where there is danger of injury from accidental contact with energized parts or improper use of the test instruments and equipment.

2.13.4.7.2 VISUAL INSPECTIONS

Test instruments and equipment and all associated test leads, cables, power cords, probes, and connectors shall be visually inspected for external defects or damage before being used on any shift. If there are defects or evidence of damage that might expose an employee to injury, the defective or damaged item shall not be used until required repairs and tests have been made.

2.13.4.7.3 RATING INSTRUMENTS AND EQUIPMENT

Test instruments and equipment and their accessories shall be rated for the circuits and equipment to which they will be connected and shall be suitable for the environment in which they will be used.

2.13.4.7.4 CALIBRATION OF ELECTRICAL INSTRUMENTS

The American National Standards Institute (ANSI) standard C39.1 defines the minimum performance and general requirements level for electrical instruments. ANSI standards also ensure that an instrument, when calibrated to National Institute of Standards and Technology (NIST) traceable standards, is capable of transferring that quality of measurement to field conditions within specified limits, where that level of measurement quality is needed.

A record should be maintained for each instrument, by serial number or equivalent method, showing dates of inspection, calibration data as received, the date when it should be recalled from the field and a recalibration check made, and any interim repairs. After a period of time, it should become obvious what frequency needs to be established for calibrating each instrument.