What hazards do you need to worry about when working around common low voltages such as 120VAC and 208VAC? It is helpful to consider the two electrical hazards separately.
Shock
NFPA 70E 2024 - 130.4(G)(1) states that no qualified person shall approach or take any conductive object closer to exposed energizedelectrical conductors or circuit parts than the restricted approach boundary.
The restricted approach distance for 120VAC is listed in NFPA 70E 2024 table 130.4(E)(a) as “Avoid contact”.
Per NFPA 70E 2024, the definition for Exposed (as applied to energized electrical conductors or circuit parts), is: Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to electrical conductors or circuit parts that are not suitably guarded, isolated, or insulated.
Ask yourself- can I avoid contact without trying? A good example of this would be if there are no exposed energized conductors. On the other hand, can inadvertent contact with exposed energized conductors be made? For example, using a multi meter. If the answer is yes rubber insulating gloves need to be worn.
Another Rozel post from 2020 specifically discussing 120VAC including an OSHA letter of interpretation, can be found here: https://www.70econsultants.com/is-ppe-required-when-working-on-120-volt-circuits/
208VAC has a restricted approach boundary of 12", standard safe work practices as defined in NFPA 70E 2024 apply for this voltage (for example, using insulated gloves/tools). Our poster does a good job explaining the requirements of boundaries.
Arc Flash
120VAC single phase power has not been shown that it can create an arc flash hazard greater than 1.2 cal/cm^2 @ 18" working distance. Recent testing and documentation to support this claim was published in thefollowing paper: ARC FLASH IN SINGLE PHASE POWER DISTRIBUTION, IEEE Paper No. ESW2024-33 (John F. Wade, Terry W. Becker). Keep in mind, small pieces of metal could still ejected in a 120VAC fault resulting in something such as eye damage, protection should be considered.
208VAC, three phase, may create an arc flash, refer to the label on your equipment for incident energy value or be sure to include it in your arc flash evaluation.
Simple tasks such as turning a breaker on/off in a 208VAC panel should be considered. Refer to NFPA 70E 2024 110.2(B) Exception No. 1: Normal operation of electric equipment shall be permitted where a normal operating condition exists. A normal operating condition exists when all of the following conditions are satisfied:
- The equipment is properly installed.
- The equipment is properly maintained.
- The equipment is rated for the available fault current.
- The equipment is used in accordance with instructions included in the listing and labeling and in accordance with manufacturer’s instructions.
- The equipment doors are closed and secured.
- All equipment covers are in place and secured.
- There is no evidence of impending failure.
Examples of normal operation tasks include turning a breaker on or off. If the breaker tripped or work was performed to change the circuit while the breaker was off, it is no longer "normal".
Standards are meant to set a minimum level of expectation. There are many circ*mstances that might create the need for more stringent requirements. Regardless of what standards say, if a local facility policy requires additional PPE then the more strict rule should be followed.
