Electrical Equipment Labels

NOTE This standard governs what is fastened or adhered to the outside of an electrical enclosure after it arrives on site: the nameplate that names the equipment and says where it is fed from, the nameplate on each device and compartment inside a lineup, the circuit directory in a panelboard door, the signs NFPA 70 requires on the equipment itself, the arc-flash warning label as a printed product, and the available fault current marking. It settles the material, the colors, the character heights, the attachment and the installation of every one of them, so that each equipment standard can require a label and point here for how it is made. (1.1)

NOTE The label on the enclosure and the marking on the wiring are two trades' worth of work and two standards. Everything that identifies a conductor, a cable, a raceway, a box cover or a buried run is the wiring system's identification and is governed by Electrical IdentificationWiring System IdentificationResolves to the current adopted revision.sync/electrical-identification; everything on the face of an enclosure is governed here. The two standards share the project's system colors and the equipment designations, and neither restates the other. (1.2)

NOTE Three documents feed the labels under this standard and none of them is written here. The arc-flash label carries the values, the method, the operating states and the signal word that the label schedule of Arc Flash StudyArc-Flash StudyResolves to the current adopted revision.sync/arc-flash-study states for each bus; this standard governs the stock it is printed on, its size, its attachment and where it is fixed. The available fault current marking carries the value and the date Short Circuit StudyShort-Circuit StudyResolves to the current adopted revision.sync/short-circuit-study states. The designation and the source on every nameplate come from the one-line diagram. A label is only as correct as the document behind it, and a label printed from a draft is replaced when the document is final. (1.3)

NOTE The following are governed elsewhere and are outside this standard: (1.4)

NOTE The decisions the engineer makes under this standard are few and independent of one another: the nameplate material and its colors, the character heights, the attachment method, the form of the circuit directory, the stock of the safety signs and of the arc-flash label, the form of the available fault current marking and of the emergency system marking, and the mounting height. What each label says is not a decision; it follows from NFPA 70 and from the one-line diagram. (1.5)

NOTE NFPA 70 says which labels an installation carries and the few words some of them must use; NFPA 70E 130.5(H) says what the arc-flash label states; ANSI Z535.4 says how a safety sign is laid out and colored so that a worker reads it the same way on every piece of equipment; UL 969 is the test that a pressure-sensitive label stays adhered and legible under the heat, humidity and exposure it is listed for. The four do not overlap, and this standard cites each for its own part. (2.3)

NOTE The nameplate schedule is reviewed against the one-line diagram line by line, because a nameplate that names the wrong source sends the next electrician to the wrong panel to de-energize it, and no quality of engraving corrects that. (3.1.2)

NOTE The editable schedule and directory are what let the Owner replace one nameplate or reprint one directory after a circuit is moved without re-creating the format, and they are the deliverable that keeps the labels matching the installation after the Contractor has left. (3.2.2)

NOTE A UL 969 listing covers a stock, an adhesive and a printing method as one system, and a legend printed on listed stock with an unlisted ribbon fades while the stock stays put; the blank label and the printed label are two different products, and the listing of the second is the one that matters. (4.1.3)

NOTE A conditioned electrical room is where most of the labels under this standard are installed, and the materials offered as the norm are rated for that service; an outdoor enclosure, a wash-down area, a chemical room, a boiler room and a classified location are different services, and the clauses below raise the material at those locations without changing the selection for the rest of the project. (5.1)

NOTE A hole drilled in an explosionproof or dust-ignitionproof enclosure voids its listing, and the flame path of such an enclosure is not restored by a sealant; the adhesive label is therefore the rule in a classified location, and its stock is one listed for the temperature class of the enclosure. (5.6)

NOTE Engraved laminated plastic is the nameplate on most distribution equipment, because the core color is the legend and cannot fade or peel, a shop engraves it to a consistent depth, it takes screws or adhesive, and it is the cheapest to replace one at a time, which is why it is the default; its limits are heat above the laminate's rating and the ultraviolet exposure of an unstabilized grade outdoors. Anodized aluminum is engraved through the anodized layer to a bright legend and withstands sun, heat and most weather, at the cost of a legend that reads as metal on metal in dim light and a plate that dents. Stainless steel is the plate that survives wash-down, chemicals and abuse and is the rule of a treatment plant or a food process area, at the highest cost and with a legend that needs filling to read. A printed polyester label with an overlaminate is the lowest cost and the fastest to produce in quantity, prints in full color and is the natural product where a project labels hundreds of small enclosures, and its life is the life of the adhesive and the overlaminate in that environment, which the UL 969 listing states. (6.1.2)

NOTE A 1/16 in laminate is the thickness most engraved nameplates are made to, rigid enough not to bow under two screws and thin enough to engrave in one pass, which is why it is the default; 1/32 in is a flexible laminate used only where the plate is adhered to a curved or small surface, and 1/8 in is bought where the plate is large, where it is screwed to an uneven surface, or where the fabricator's stock for a metal plate is that thickness. (6.1.7)

NOTE Black characters on a white face read at the greatest distance under the lighting of an electrical room and photograph legibly for the record, and they are the colors of most normal power nameplates, which is why they are the default; white on black is the convention of some Owners and utilities and reads better on a light-colored enclosure; gray on black suits a dark enclosure finish; a clear face over a white core is specified where the enclosure color is to show through the plate. The choice is the Owner's convention first and legibility second, and a project with an Owner standard follows it. (6.2.2)

NOTE One convention names the system colors for the whole project, and it lives with the wiring identification because the same colors band the raceways, mark the box covers and appear on the posted legend; the nameplate takes the color from that convention rather than naming its own, so that an emergency panelboard, its feeder raceway and its junction boxes are all the one color. (6.2.4)

NOTE A 1/2 in designation reads from the working clearance in front of the equipment and from the room door, and 1/4 in secondary lines and 3/16 in device nameplates read from the working position without stooping; these are the heights most nameplate schedules carry, which is why they are the defaults. A larger designation is specified in a high-bay room, on outdoor equipment read from a walkway, and on equipment above eye level; a smaller device nameplate is accepted only where the device face has no room for 3/16 in characters, and the panel schedule then carries the full text. (6.3.5)

NOTE Screws or rivets hold a nameplate for the life of the equipment through the heat cycling of an electrical room and the sun of an outdoor enclosure, which is why they are the default on distribution equipment; they need a hole, which is the reason they are forbidden where a hole would void a listing or a rating. Fasteners with an adhesive backing hold the plate flat during installation and keep it in place if a screw loosens, at a small added cost. High-bond foam adhesive alone needs no hole and is the attachment on a glass window, a plastic deadfront and an enclosure whose rating a hole would compromise, and it holds only on a clean smooth surface within the adhesive's temperature rating, failing first on a hot or outdoor enclosure. A manufacturer's holder or recess is the attachment where the equipment provides one, and it holds the standard plate the manufacturer sizes it for. (6.4.2)

NOTE A nameplate attached to a bucket door alone travels with the bucket when buckets are swapped, and the next technician reads the wrong motor on the door in front of a different starter; the structure nameplate is the one that stays true. (6.4.6)

NOTE The source on a nameplate is the designation and the room of the overcurrent device that feeds the equipment, not the name of the room the equipment stands in; a nameplate that reads a designation alone satisfies no one at 2 a.m., and NFPA 70 408.4(B) is the rule that puts the source on it. (7.1.5)

NOTE A breaker marked SPARE is one the next electrician loads without research, and one marked FUTURE is one that sends them looking for a drawing that no longer exists; the two words are a status, and the status is kept current with the directory. (7.1.8)

NOTE The printed card in the holder the manufacturer builds into the door is the directory of most panelboards, because it is reprinted from the record file and slid in when a circuit changes, which is why it is the default; a card under a clear cover on the door face is read without opening the door and suits a switchboard or motor control center whose directory is long; an engraved plate cannot be altered without a new plate, which some Owners want on life-safety equipment and which costs a plate at every circuit change; a laminated card adhered inside the door is the lowest cost and the one that is torn off and replaced with handwriting first. (8.2)

NOTE A 10 point font fills a 42-circuit card in the standard holder and reads without a light, which is why it is the default; 8 point is accepted only where a dense switchboard directory would otherwise run to two cards, and 12 or 14 point is specified where the directory is read from the door face at a distance or by a maintenance staff who have asked for it. (8.7)

NOTE A polyester label with an overlaminate is printed in the ANSI Z535 colors on demand, carries a UL 969 listing for most indoor and sheltered outdoor exposures, and is the stock of most safety signs on electrical equipment, which is why it is the default; vinyl conforms to a curved or textured surface and is the stock chosen for a small or rounded enclosure, with a shorter life in sunlight than polyester; an engraved plate reproduces the signal word colors in the laminate's core and face and survives wash-down and abuse, and it carries no pictorial unless one is engraved; a printed aluminum sign is the stock of an outdoor switchyard, a generator yard and a rooftop, mechanically fastened, and is the costliest per sign. (9.1.5)

NOTE Each marking in this article is triggered by a condition of the one-line diagram, and none of them is a datasheet choice: a project with one utility service and no on-site source carries none of the source plaques, and a project with a generator, an inverter and a series-rated panelboard carries all of them. The Contractor reads the triggers from the reviewed one-line diagram and the study reports, and the nameplate schedule lists each sign the triggers call for. (9.2.10)

NOTE A polyester label with an overlaminate prints the signal word colors and the pictorial in one pass, is reprinted when the study is revised, and lasts the review interval of the study in a conditioned or sheltered location, which is why it is the default; vinyl conforms to a curved enclosure and fades sooner in sunlight; an engraved plate with a window holds a printed insert that is swapped at each study revision while the plate and its fasteners stay, and suits a wash-down area; a printed metal plate is the product of an outdoor switchyard or a rooftop, where an adhesive label fails within a few seasons, and it is replaced whole at each revision. (10.1.3)

NOTE A 1/8 in data block reads from the working distance the label itself states, and fits the values on the label sizes the stock manufacturers supply, which is why it is the default; 3/32 in fits a label on a small enclosure at the limit of legibility, and 3/16 in or 1/4 in is specified where the label is read from the floor on equipment mounted high or behind a barrier. (10.1.5)

NOTE A generic warning per NFPA 70 110.16(A) at energization, replaced by the study label when the values arrive, is what most projects do, because the study's settings are verified only after the equipment is installed and energized, which is why it is the default; holding energization until the study label is on the door is the rule of an Owner whose safety program forbids a generic label and of a project whose study is finished before equipment delivery, at the cost of a schedule dependency on the study. (10.2.2)

NOTE Thirty days covers printing, the submittal of the printed sample and a site visit to every piece of equipment on most projects, which is why it is the default; a shorter period is set where the Owner occupies before the study arrives, and a longer one where a campus study covers hundreds of buses and the labels are installed building by building. (10.2.5)

NOTE A separate label is revised under NFPA 70 110.24(B) without touching the nameplate or the arc-flash label, and it is read by the inspector who looks for it beside the nameplate; a field on the arc-flash label keeps the two study values on one sign and is revised with it; a line on the engraved nameplate is permanent until the nameplate is replaced, which an Owner who re-engraves at every modification accepts and others do not. No form is the norm across projects, so the field carries no default; the one condition that decides it is how the Owner intends to revise the value after a service modification. (11.2)

NOTE A nameplate in the system color that names the system is one plate and is the form of most projects that color-code nameplates; a separate system label is added to a nameplate of the normal color where the Owner's convention keeps every nameplate the same color, and it is the only form available on equipment whose nameplate the manufacturer furnished; both together give the recognition of the color and the words of the label and are the form some healthcare and data center Owners require. The choice follows the nameplate color convention selected under this standard, so the field carries no default. (12.2)

NOTE The marking of the boxes and raceways of these systems is governed by Electrical IdentificationWiring System IdentificationResolves to the current adopted revision.sync/electrical-identification, and the marking under this article is the one on the equipment enclosure. (12.3)

NOTE The sequence puts the designation and the source on the door before the first person opens it energized, and leaves the directory until the circuits are real; a directory printed from the design schedule is the one the commissioning agent finds wrong. (13.1.3)

NOTE Sixty inches puts the nameplate at the eye level of a standing worker and above the handles and meters of most equipment fronts, and it is the height most projects use, which is why it is the default; a lower height is used where the equipment is short or the nameplate must clear a window, and a higher one where the equipment is read over a barrier or from a mezzanine. (13.2.2)

NOTE Two labels on one door that disagree about the source or the fault current leave the worker to guess which is current, and the guess is the hazard; the old label comes off when the new one goes on. (13.2.7)

NOTE One year is the general-conditions warranty and is what a label and nameplate package commonly carries, because the labels are a small part of a larger electrical warranty, which is why it is the default; two to five years is specified where the Owner has had adhesive labels fail in an unconditioned or outdoor location and wants the replacement cost on the Contractor through that exposure. (15.2)

NOTE Ten blanks of each color cover the first few years of moved circuits and added disconnects on most projects and cost little, which is why they are the default; zero records that the Owner has its own engraving source, and a larger stock suits a campus or a plant with a maintenance shop that engraves its own. (16.2)