California sign lighting rules

Check your sign

Enter the lit area of one face and the total input wattage of the lighting (from the power supply or ballast nameplates). For the source route, enter the efficiency printed on the power supply or transformer.

Route 1: maximum allowed lighting power

Section 140.8(a) sets the limit by illuminated area. An internally illuminated sign is lit from inside, with a luminous message area, such as a cabinet sign or channel letters. Its lighting may not exceed the illuminated area times 12 watts per square foot. For a double-faced sign, only the area of one face is used.

An externally illuminated sign or billboard is lit by a fixture outside the sign aimed at its face. The limit is the illuminated area times 2.3 watts per square foot, and only the area lit without obstruction counts.

Worked example: a 4 ft × 10 ft double-faced cabinet sign has 40 sq ft per face, so the allowance is 40 × 12 = 480 W. Lighting drawing 300 W passes. The same 40 sq ft lit by flood lights allows 40 × 2.3 = 92 W.

Route 2: compliant light sources

Section 140.8(b) lets a sign pass without a wattage count if it uses only these sources:

• LEDs with a power supply efficiency of 80% or more. Single-voltage external power supplies of 250 W nameplate output or less must also meet the state Appliance Efficiency Regulations.
• Neon or cold cathode lamps with a transformer or power supply efficiency of at least 75% when rated output current is under 50 mA, or at least 68% at 50 mA or more, measured at 100% tubing load.

A sign that mixes in incandescent sources inside a cabinet cannot use this route and must meet Route 1. Bare incandescent "chaser" lamps outside any cabinet or EMC are not regulated by §140.8; only the control rules apply to them.

Required controls (§130.3 and §110.12)

• Indoor signs: an automatic time-switch or astronomical time-switch control. Exit signs and signs at healthcare facilities are excepted. The sign does not have to go dark in the day; the owner sets the schedule.
• Outdoor signs: a photocontrol plus an automatic time-switch, or an astronomical time-switch. Signs in tunnels and large permanently covered areas lit around the clock are exempt.
• Outdoor signs lit day and night (on at night and for more than 1 hour of daylight): a dimmer that can automatically cut sign lighting power by at least 65% at night.
• Electronic message centers with connected lighting load over 15 kW: demand-responsive controls, unless a health or life-safety rule does not allow the EMC to dim.

Does this apply to my existing sign?

New signs must meet §110.9, §130.0, §130.3 and §140.8. An existing internally or externally lit sign has to meet the power rules (§141.0(b)2M) when the alteration does any of these:

• increases the connected lighting power;
• replaces and rewires more than 50% of the ballasts;
• moves the sign to another spot on the site or to another site.

Replacing only the lamps, only the sign face, or ballasts without rewiring does not trigger them. A new face may still need a city sign permit; see replacing a sign face.