Ask Lewis Bass: A Question About Field Labeling

Ask Lewis Bass: A Question About Field Labeling

Welcome to another blog in our ongoing series, Ask Lewis Bass!

This series features actual submitted questions from companies in the industries we provide engineering safety consulting services to.

Topics covered include those associated with our work in 3rd party field labeling, SEMI S2/S8/EMC/F47 testing and design, CE Marking evaluations, and general engineering safety consulting questions.


Hi Lewis Bass,

We are preparing to have a 3rd party field evaluation performed on a new unlisted machine (CE marking only) that we had shipped from a vendor overseas.

The machine is currently out of its packaging but it is not in it’s final install location and it will be at least another month or two before we can hook it up and make it operational in our facility. The final location is in another room down a long hallway…maybe 100 feet away?

Since our schedule is so tight I’d like to save some time and get the field evaluation performed right away. Can I have this performed on the machine prior to its final install and also if the machine is not 100% operational?


Asked by Laura in Santa Clara, CA


Lewis Bass:

Hi Laura,

We are often asked questions like these when we encounter new clients who’ve had no experience with field labeling (also known as a 3rd party field evaluation).

The NFPA code requirements that local AHJs mandate for projects in their area of influence can vary wildly.

In certain situations an AHJ may even disregard the need for a field evaluation at the final install location if the previous location was similar enough in terms of grounding and electrical service.

This is not always the case, however, so it is best to be aware of these potential blockers ahead of time by being proactive and reaching out to your local AHJ directly for their views on your situation. Lewis Bass has also created a handy safety flyer for you to self-identify unlisted equipment in your facility that may need evaluation per your AHJ’s discretion.

In the situation that you have described (especially in Santa Clara,CA) I would strongly advise you to have the machine electrically evaluated at its final install location down the hall and to not bother with an evaluation beforehand unless you believe there are areas of non-compliance present in the machine.

With regards to the machine not being fully operational—remember, a machine is being electrically tested and it needs to be under load for many of the test being performed to verify that it is operating within its acceptable range per the manufacturer’s documentation.

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