What goes on an industrial control panel nameplate

Short answer: the summed horsepower does not go on the nameplate. No US or Canadian code asks a control panel nameplate for horsepower; UL 508A and CSA C22.2 No. 14 mark the supply voltage, phases, frequency, total full-load current, short-circuit current rating and enclosure type, and each motor keeps its horsepower on its own plate. For a 460 V, three-phase panel controlling a 10 hp fan, a 5 hp pump and a 2 hp conveyor, the plate reads 460 V, 3 ph, 60 Hz, 26.1 A, SCCR 10 kA, Type 4X. The sections below take each marking in the order you meet it on the job.

Does any code ask for a total horsepower on a panel nameplate?

No. The NEC and UL 508A ask the panel nameplate for electrical ratings — voltage, phases, current and short-circuit current rating — plus the enclosure type number. Neither document mentions horsepower, summed or motor by motor.

Horsepower describes a shaft, and a panel feeds several shafts through different contactors and overload settings. Two 5 hp motors are not one 10 hp machine. Their combined figure matches no single ampere value, because each motor converts power at its own efficiency and service factor. Current at the marked voltage is the value the codes want, since that is what sizes the feeder conductor, the disconnect and the overcurrent protection. When a facility engineer wants load data on the plate, add a supplemental line below the required markings that lists the motors: 10 hp fan, 5 hp pump, 2 hp conveyor. The list keeps every number usable; a sum of 17 hp gives the next engineer nothing to size a circuit from.

What goes on an industrial control panel nameplate?

The nameplate carries the maker's name, the listing file number when the panel has a UL 508A listing, and the supply voltage. It also carries the phases and frequency, the total full-load current, the short-circuit current rating and the enclosure type number.

UL 508A carries every marking the NEC's industrial-control-panel rules reference and adds its own. A plate built to that standard satisfies the code markings at the same time.

A panel with two supplies marks each one, for example 460 V for the motors and 120 V for a separately fed control circuit. A panel that distributes to output circuits marks those ratings too, so the installer can connect a load without opening the door. NEC 409.2 defines an industrial control panel as an assembly of two or more power circuit components, control circuit components, or both. UL 508A is the standard for listing one, and the UL 50E and NEMA 250 listing guide walks through what the listing covers. The US enclosure design requirements for control panels collect the rest of the panel-side rules.

How do you work out the full-load amps to mark?

Add every load's full-load current at the marked voltage: 14 A for the 10 hp fan, 7.6 A for the 5 hp pump and 3.4 A for the 2 hp conveyor at 460 V, three-phase — 25.0 A, plus 1.1 A of control power, marked 26.1 A.

The per-motor values come from the NEC's full-load current table for three-phase motors: at 460 V the values are 14 A for 10 hp, 7.6 A for 5 hp and 3.4 A for 2 hp; at 230 V the same motors draw 28 A, 15.2 A and 6.8 A. Take the figure from each motor's own nameplate when the motor differs from the table. The control load adds the same way: a 500 VA control transformer at 460 V draws 500 ÷ 460 = 1.1 A at its primary.

A panel with drives takes each drive's rated input current from its instructions in place of the motor value. Working from the summed horsepower instead puts a guess on a code marking: converting 17 hp back to amps needs an efficiency and a power factor that no plate states. Assumed values between 80 % and 95 % efficiency move the result by several amps. The walk-through on calculating equipment nameplate full-load amps for 3-phase machines covers panels that mix motors, heaters and drives.

What sets the short-circuit current rating on the nameplate?

The lowest short-circuit current rating of any power-circuit component sets the number: a feeder breaker marked 65 kA cannot lift a panel whose branch breaker or drive withstands 10 kA, so the nameplate reads SCCR 10 kA.

The builder works the rating out from the power-circuit components, the current-limiting fuses and the protective devices ahead of each one, then marks the single lowest result. On site, compare the marked number with the available fault current at the supply terminals: a service that can deliver 25 kA cannot feed a panel marked 10 kA. Close that gap on the supply side — a smaller transformer, a longer cable run or current-limiting fuses, which clamp the let-through current a fault hands the components downstream. De-energize, lock out and verify absence of voltage before you open a panel to read component ratings.

What enclosure type goes on the nameplate?

The enclosure type number is a required marking — NEC 409.110 asks for it on the panel — so a washdown panel built in a 316L stainless box marks Type 4X, with IP66 alongside for international specifications.

The type tells the installer where the finished panel may live. Type 1 suits a dry indoor room. Type 12 adds dust and dripping oil or coolant for a machine-shop floor. Type 4 takes hose-directed washdown water, and Type 4X adds the corrosion resistance of 304 or 316L stainless for salt, brine and chemical areas. The NEMA enclosure types guide covers what each type is tested for, and NEC enclosure type requirements for boxes and motors lists which types the code pairs with which conditions.

In US installations, NEC 110.28 states that an IP rating cannot replace the enclosure type rating, which is why a panel headed for both markets carries the type and the IP code together. The IP to NEMA conversion explains how the scales map. The marked type also has to survive the panel build: every gland, hub and cutout carries its own rating, and the lowest one sets the finished panel. A Type 4X box cut for a Type 12 connector caps the assembly at Type 12, a point what drilling does to an enclosure rating develops. Our 304 and 316L enclosures are rated NEMA 4X / IP66 by the manufacturer; not UL listed.

What stays on each motor's own nameplate?

Each motor keeps its own plate with its horsepower, voltage, full-load amps, frame size, service factor and design letter, and nothing from that plate moves to the panel except the amps, added into the panel total.

The motor plate belongs to the motor maker, and its values size the branch circuit, the starter and the overload. Carry each motor's data onto the machine documentation or a load schedule mounted inside the door. The schedule answers what a summed figure cannot: which motor draws what, on which breaker, at which horsepower, so the next technician sizes a replacement branch without guessing. A plate line reading connected motors — 10 hp fan, 5 hp pump, 2 hp conveyor — carries more information than a single 17 hp figure and costs the same space.

What does a Canadian job put on the nameplate?

Canada marks the same fields: CSA C22.2 No. 14 asks a control panel for supply voltage, phases, frequency, full-load current, short-circuit current rating and the enclosure type, and no Canadian code asks for a horsepower total.

C22.2 No. 14 is the Canadian standard for industrial control equipment, and the newer C22.2 No. 286 refines the rules for industrial machinery control panels. Neither document contains a summed-horsepower marking, so the practice lives in shop standards and individual inspectors' preferences, not in the code. Where a shop standard or an inspector asks for horsepower on the plate, handle it as on a US job: supplemental data below the required markings, listed motor by motor. A panel built to both standards carries both listing marks and serves a cross-border machine without a second set of plates.

How do you order an enclosure that matches the nameplate?

Choose the enclosure type before you build the panel, because the finished nameplate quotes it: set material, size, NEMA type and every cutout in the enclosure builder, and a panel in a 316L box marks Type 4X.

Pick the type from the environment first: Type 4X in 304 stainless covers indoor washdown in food and beverage plants, and 316L covers salt air, brine and chlorides. The enclosure builder configures material, size, NEMA type, mounting, door, DIN rails, climate options and quick cutouts in 3D. The finished enclosure is delivered in 10 business days from your approval of the drawing. For a fully custom build, the custom enclosures page takes material, dimensions and every cutout from one piece, and how to size an electrical enclosure covers the layout that decides the depth. Order glands and any vents to the same type rating as the box, because the finished panel inherits the lowest rating in its wall. A classified area needs enclosure types certified for that duty by an approved equipment maker; those are outside what we build, and our catalog stops at the general-purpose and washdown types.

Catalog dimensions to compare

Compare these catalog dimensions with your component layout. Open each enclosure for its rating, material and usable space, then check those specifications against your application.

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