The latest edition of NFPA 70E (2021) does not specify “where” the label must go (nor have previous versions). It only indicates which type of equipment must receive a label and what must be on the label. Even with this guidance there are still many questions.
NFPA 70E 2021 130.5(H): Electrical equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centers that are in other than dwelling units and that are likely to require examination, adjustment, servicing, or maintenance while energized shall be marked with a label containing all the following information:
1) Nominal system voltage
2) Arc flash boundary
3) At least one of the following:
a) Available incident energy and the corresponding working distance, or the arc flash PPE category in Table 130.7(C)(15)(a) or Table 130.7(C) (15)(b) for the equipment, but not both
b) Minimum arc rating of clothing
c) Site-specific level of PPE
Exception No. 1: Unless changes in electrical distribution system(s) render the label inaccurate, labels applied prior to the effective date of this edition of the standard shall be acceptable if they complied with the requirements for equipment labeling in the standard in effect at the time the labels were applied.
Exception No. 2: In supervised industrial installations where conditions of maintenance and engineering supervision ensure that only qualified persons monitor and service the system, the information required in 130.5(H)(1) through 130.5(H)(3) shall be permitted to be documented in a manner that is readily available to persons likely to perform examination, servicing, maintenance, and operation of the equipment while energized.
The method of calculating and the data to support the information for the label shall be documented. The data shall be reviewed for accuracy at intervals not to exceed 5 years. Where the review of the data identifies a change that renders the label inaccurate, the label shall be updated. The owner of the electrical equipment shall be responsible for the documentation, installation, and maintenance of the marked label.
Canada’s equivalent to NFPA 70E, CSA Z462, provides guidance: “a label needs to be readily visible to the worker and alert the worker to the potential hazard in time to take appropriate action”
We place labels near the main disconnect of a machine. Large machines may receive multiple labels if there are multiple disconnects. Sometimes it makes sense to place the label adjacent to the disconnect so that it is more visible to the end user.
The ultimate goal is to place the label so it may warn the worker of the hazard prior to commencing work.
Each type of equipment gets handled differently. MCCs with many doors may receive one label per door or one per column depending on the configuration or our customer’s preference. Bus bars are labeled on the bus itself and not bus taps/disconnects as these can move from one bus to another.
Being in the northern hemisphere it’s preferable that outdoor labels do not face the south or up towards the sky because they will have the most sun exposure. The red/orange and black on a label will fade over time with enough UV exposure. However, it does not make sense to put a label on the back side of the equipment when a disconnect is on the front, sometimes it is a case by case decision.
As seen above, the absence of a label is discussed in NFPA 70E 2021 130.5(H) Exception No. 2 In supervised industrial installations where conditions of maintenance and engineering supervision ensure that only qualified persons monitor and service the system, the information required in 130.5(H)(1) through 130.5(H)(3) shall be permitted to be documented in a manner that is readily available to persons likely to perform examination, servicing, maintenance, and operation of the equipment while energized. We frown upon only using this exception. It is unlikely in most installations that someone can completely meet the requirements (i.e. what happens if a 3rd party contractor is called to perform work and he does not know where to find the proper document or other internal requirements). This documented method should be a supplemental, if the sticker is not legible or if someone questions the value of the sticker, go to the document. This would also help meet the requirements of the rest of NFPA 70E 2021 130.5(H) “The method of calculating and the data to support the information for the label shall be documented”.
More specific questions can be directed to us here: info@70eConsultants.com