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This material is for training purposes only to inform the reader of occupational safety and health best practices and general compliance requirements and is not a substitute for provisions of the OSH Act of 1970 or any governmental regulatory agency.
  MODULE 6: ELECTRICAL PROTECTIVE EQUIPMENT

Care and use of electrical protective equipment

To prevent injury from exposure to electrical conductors, it's important that all electrical protective equipment be maintained in a safe, reliable condition. Electrical protective equipment includes the following:
  • Insulating blankets,
  • covers,
  • line hose,
  • gloves, and
  • sleeves made of rubber
All electrical protective equipment made of rubber should meet the established safety standards and specifications discussed below.

Voltages

Maximum use voltages must conform to those listed in Table I-5. 


 Table I-5. - Rubber Insulating Equipment Voltage Requirements
 ____________________________________________________________________
               |             |                   |	   
  Class of     | Maximum use | Retest voltage(2) | Retest voltage(2)  
  equipment    |  voltage(1) |     ac - rms      |       dc - avg
               |  ac - rms   |                   |
 ______________|_____________|___________________|__________________
               |             |                   |
 0.............|       1,000 |            5,000  |      20,000
 1.............|       7,500 |           10,000  |      40,000
 2.............|      17,000 |           20,000  |      50,000
 3.............|      26,500 |           30,000  |      60,000
 4.............|      36,000 |           40,000  |      70,000
 ______________|_____________|___________________|__________________
Footnote(1) The maximum use voltage is the a-c voltage (rms) classification of the protective equipment that designates the maximum nominal design voltage of the energized system that may be safely worked. The nominal design voltage is equal to the phase-to-phase voltage on multiphase circuits. However, the phase-to-ground potential is considered to be the nominal design voltage:

[1] If there is no multiphase exposure in a system area and if the voltage exposure is limited to the phase-to-ground potential, or

[2] If the electrical equipment and devices are insulated or isolated or both so that the multiphase exposure on a grounded wye circuit is removed.

Footnote(2) The proof-test voltage must be applied continuously for at least 1 minute, but no more than 3 minutes.

Inspecting equipment

To make sure electrical protective equipment actually performs as designed, it must be inspected for damage before each day's use and immediately following any incident that can reasonably be suspected of having caused damage. Insulating gloves must be given an air test, along with the inspection.

Defects

Insulating equipment must not be used if any of the following defects are detected:
  • A hole, tear, puncture, or cut;
  • Ozone cutting or ozone checking (the cutting action produced by ozone on rubber under mechanical stress into a series of interlacing cracks);
  • An embedded foreign object;
  • Any of the following texture changes: swelling, softening, hardening, or becoming sticky or inelastic.
  • Any other defect that damages the insulating properties.

Insulating equipment found to have other defects that might affect its insulating properties must be removed from service and returned for testing. It must be cleaned as needed to remove foreign substances. It must be stored in such a location and in such a manner to protect it from:

  • light
  • temperature extremes
  • excessive humidity
  • ozone
  • other injurious substances and conditions
Gloves

Protector gloves must be worn over insulating gloves. An exception is when using Class 0 gloves, under limited-use conditions, where small equipment and parts manipulation necessitate unusually high finger dexterity. But, it's important to note that extra care must be taken while visually examining the glove. Also, make sure to avoid handling sharp objects.

Any other class of glove may be used for similar work without protector gloves if the employer can demonstrate that the possibility of physical damage to the gloves is small and if the class of glove is one class higher than that required for the voltage involved. Insulating gloves that have been used without protector gloves may not be used at a higher voltage until they have been tested.

Testing

Electrical protective equipment must be subjected to periodic electrical tests. Test voltages and the maximum intervals between tests must be in accordance with Table I-5 and Table I-6. 

  
Table I-6. - Rubber Insulating Equipment Test Intervals
 ___________________________________________________________________
                             |
     Type of equipment       |       When to test
 ____________________________|______________________________________
                             |
 Rubber insulating line hose | Upon indication that insulating value
                             |   is suspect.
 Rubber insulating covers    | Upon indication that insulating value
                             |   is suspect.
 Rubber insulating blankets  | Before first issue and every 12 months
                             |   thereafter(1).
 Rubber insulating gloves    | Before first issue and every 6 months
                             |   thereafter(1).
 Rubber insulating sleeves   | Before first issue and every 12 months
                             |   thereafter(1).
 ____________________________|_______________________________________
Footnote(1) If the insulating equipment has been electrically tested but not issued for service, it may not be placed into service unless it has been electrically tested within the previous 12 months.

The test method used must reliably indicate whether the insulating equipment can withstand the voltages involved. Repaired insulating equipment must be retested before it may be used by employees.

Note: Standard electrical test methods considered as meeting this requirement are given in the national consensus standards of The American Society for Testing and Materials (ASTM).

If the insulating equipment fails to pass inspections or electrical tests it may not be used by employees, except as follows:

  • Rubber insulating line hose may be used in shorter lengths with the defective portion cut off.
  • Rubber insulating blankets may be repaired using a compatible patch that results in physical and electrical properties equal to those of the blanket.
  • Rubber insulating blankets may be salvaged by severing the defective area from the undamaged portion of the blanket. The resulting undamaged area may not be smaller than 22 inches by 22 inches (560 mm by 560 mm) for Class 1, 2, 3, and 4 blankets.
  • Rubber insulating gloves and sleeves with minor physical defects, such as small cuts, tears, or punctures, may be repaired by the application of a compatible patch. Also, rubber insulating gloves and sleeves with minor surface blemishes may be repaired with a compatible liquid compound. The patched area must have electrical and physical properties equal to those of the surrounding material. Repairs to gloves are permitted only in the area between the wrist and the reinforced edge of the opening.

Certification

The employer must certify that equipment has been tested in accordance with the requirements of the standard, and the certification must identify the equipment that passed the test and the date it was tested. Marking equipment and entering the results of the tests and the testing dates onto logs are two acceptable ways to meet this requirement.



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