230 V vs 120 V: write the mains before the paint

Channel-letter and cabinet RFQs fail most often on voltage, not on paint. Europe, the United Kingdom, and Australia run nominal 230 V single-phase mains. North America runs nominal 120 V for small branch circuits, with 277 V common in US commercial lighting panels. If you copy a European letter quote onto a Texas job, the driver list is fiction. This note tells a buyer how to write the electrical block so three factories can answer the same question.

Write the mains first, not the colour temperature

The International Electrotechnical Commission publishes the world plug and voltage overview used by almost every travel and product page. Use IEC World Plugs as the public reference for which countries sit on 230 V / 50 Hz versus 120 V / 60 Hz. Do not rely on a salesperson’s memory of “Europe is 220.” The nominal value in the IEC table is 230 V for EU/UK/AU. The US table is 120 V for typical receptacles.

In the RFQ, put one line at the top of the electrical section: “Mains at the sign: ___ V, ___ Hz, available breaker ___ A, distance from panel to sign ___ m.” Empty lines are better than guessed numbers. If the site is a US shopping centre, ask the electrician whether the lighting panel is 120/208 or 277/480. Channel-letter remote supplies are often 12 V or 24 V DC after a driver; the driver still has a mains input that must match the panel.

What the factory actually ships

A letter set is usually a low-voltage load plus one or more drivers. The buyer cares about three numbers: mains input to the driver, DC output to the modules, and the IP rating of each. A 230 V-input driver with a 24 V output is not interchangeable with a 120 V-input driver even when the modules look identical. Ask for the driver datasheet, not a photo of a white brick.

IES lighting practice documents on ies.org are the right language for night-time appearance (luminance, uniformity). They do not replace the electrical code. Use IES terms in the appearance section and IEC/national terms in the electrical section so the two conversations do not collide.

EU / UK / AU — 230 V block

State 230 V 50 Hz. Ask whether the assembly is placed on the market as a luminaire or as a kit. Ask for the driver make, model, and input range (many accept 220–240 V). Ask for IP65 or the project’s stated IP at the face and at the driver enclosure separately. Ask whether a local isolator is included. UK buyers should add a line for UKCA / competent-person responsibilities; AU buyers should add a line for the RCM path without claiming any factory is certified in this article.

Do not write “CE included” as a substitute for the voltage line. CE or UKCA marking, when it applies, is a conformity story. Voltage is a physics story. Both can be true and both can be missing.

United States — 120 V and 277 V block

State the panel voltage you actually have. If you do not know, write “electrician to confirm 120 V or 277 V before shop drawings.” Many US retail shells offer 277 V lighting. A 120 V-only driver list will be re-ordered. The US Department of Energy lighting pages at energy.gov solid-state lighting are a public primer on LED drivers and efficacy; they are not a substitute for the National Electrical Code as adopted by the city.

Ask for Class 2 versus Class 1 remote placement in writing. Ask for the maximum remote distance the factory will warrant. A 24 V run that looks fine on a bench can drop voltage across a long raceway. That is a drawing problem, not a colour problem.

RFQ paste block

Copy this block into every illuminated-letter RFQ. Leave blanks. Do not invent numbers to look prepared.

Mains at sign: ___ V ___ Hz. Breaker: ___ A. Panel type: 120/208 | 277/480 | 230/400 | other. Driver input must match mains. DC to modules: 12 V | 24 V | other. IP face: ___. IP driver: ___. Remote distance max: ___ m. Isolator: yes/no. Night viewing distance: ___ m. Letter height: ___ mm. Face material: ___. Warranty years LED / driver (named separately): ___ / ___.

If three quotes fill that block, you can compare them. If they only fill pantone and price, you are buying a rendering. Use the GSS LED / channel-letter heading to find websites that already talk in these units. Then make them fill the block. Voltage is the first filter; paint is the last.

Re-read the IEC world-plugs page when the install country changes, even inside one corporate rollout. A Dublin store and a Boston store are not the same electrical sentence. The modules might be. The drivers will not be.