Arc flash safety and thermal imaging

07-15-2019 | Thermal imaging

The National Fire Protection Association (NFPA) 70E Standard for Electrical Safety in the Workplace has come a long way regarding Personal Protective Equipment (PPE) for thermographers (people using thermal cameras).

In the 2018 edition of NFPA 70E, the if the person removing the panel covers wore full arc-rated clothing and PPE, the thermographer could elect to not wear arc-rated clothing and PPE if:

  1. They did not cross the restricted approach boundary,
  2. Break the plane of the enclosure; and
  3. Did not interact with the equipment in any way.
Preparing to perform a panel inspection with a Fluke thermal camera. Preparing to perform a panel inspection with a Fluke thermal camera.

What NFPA 70E means for thermographers

Here are a few more important points to know about these PPE recommendations for thermographers:

  • NFPA 70E represents minimum arc flash safety practices, not best safe work practices. Any qualified person about to perform a task that exposes them to electrical hazards must perform a full risk assessment, including a shock risk assessment and an arc flash risk assessment.
  • Once the panel covers are off, the area secured and inspected for possible hazards that may not be clear, then the thermographer can enter and perform the scan, wearing appropriate PPE for that level risk.

Equipment condition is a critical part of arc flash PPE assessment. As an example, see the table below, which is a partial table 130.7(C)(15)(A)(a).

TaskEquipment ConditionArc Flash PPE Required
Removal of battery intercell connector coversAll the following:
The equipment is properly installed
The equipment is properly maintained
Covers for all other equipment are in place and secured
There is no evidence of impending failure
No
One or more of the following:
The equipment is not properly installed
The equipment is not properly maintained
Equipment doors are open or not secured
Equipment covers are off or not secured
There is evidence of impending failure
Yes
Opening hinged door(s) or cover(s) (to expose bare energized electrical conductors and circuit parts)AnyYes
Perform infrared thermography and other noncontact inspections outside the restricted approach boundary. This activity does not include opening of doors or covers.AnyNo
Courtesy of the National Fire Protection Association

Also, be aware that even where the task of infrared thermography in Table 130.7 (C)(15)(A)(a) states “No PPE Required” in any condition, technicians cannot knowingly put themselves at risk, which is why the risk assessment is so critical.

Whether to wear arc-rated clothing and PPE for infrared thermography may in some cases now be a personal decision. Be aware that OSHA directs employers to supply required PPE and for employees to wear the supplied PPE, if hazards exist. A risk assessment can indicate whether such PPE is needed, and the assessment needs to be properly documented.

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