A field-applied hazard marking is required on a piece of equipment. What does the Code require of that marking?
- AIt may be handwritten with a permanent marker provided the lettering is legible from at least 3 feet away
Legibility is necessary but not sufficient. The section specifically prohibits handwritten markings except for portions expected to change.
- It must be permanently affixed, durable for the environment, and not handwritten except for parts expected to change
- CIt must be engraved on a metal plate and fastened to the equipment with rivets in every installation
Engraved metal is one acceptable method among many. Printed adhesive labels rated for the environment are equally acceptable and far more common.
- DIt must be applied at the factory by the manufacturer, because a marking applied in the field carries no weight with inspectors
Field-applied markings are required by many Code sections precisely because the information depends on the installation, not on the factory.
Why B is correct
Three requirements: effective communication of the hazard, permanent attachment, and durability suited to the location. The prohibition on handwriting has a narrow carve-out for changeable data. A marker-written label in a boiler room fails on durability alone within a year.
What this question is testing
The item tests knowledge of the general requirements governing every field-applied marking, and whether the candidate knows the narrow exception permitting handwriting.
On the job
Available fault current markings, arc-flash warning labels, service disconnect identification, and separate-supply plaques are all field-applied. The common failure is a marker on a piece of tape, which fades, curls, and falls off. Printed labels rated for outdoor or industrial exposure cost very little and survive. On any label that carries a calculated value, note the date, because the value changes when the utility transformer changes.
Memory technique
Permanent, durable, printed. Only the part that changes may be written by hand.
Exam tip
One general rule governs all field-applied hazard markings. Read it once and it answers many specific marking questions.
Where to look it up
Look in the general requirements article at the section covering marking, in the subsection on field-applied hazard markings.