2005 NEC Neon Checklist

Often, a new year brings change. New laws and regulations frequently take effect on January 1. So it goes with the National Electrical Code’s (NEC) 2005 edition, which presents new regulations for neon installation. I previewed prospective changes in NEC’s Article 600, Electric Signs and Outline Lighting, last year (see ST, April 2004, page 30).

Remember, not all municipal authorities immediately adopt the new NEC; always check with your local authority having jurisdiction (AHJ). In most cases, your electrical inspector is the AHJ, and he will know which edition is applicable to your present job.

Key changes include Article 600-32 (g), which stipulates that GTO cable extend 21/2 in. beyond the conduit for wet- or dry-location signs. Prior to the 2005 NEC change, wet-location GTO had extended 4 in. past conduit; dry applications are unchanged. Also, Section 600-2 dictates that the prefabricated sign section must carry a listing mark, and that the labels state the section number and the total number of sections employed.

Moreover, I’ve included a section pertaining to Class 2 power supplies. However, this list focuses only upon high-voltage neon signage. For other electric-sign types, refer to the NEC’s Article 600.

From my many sign inspections, I could tell more stories of improper procedures than would fit in this magazine. Often, basic requirements are simply overlooked. I’m not only referring to disreputable, fly-by-night installers who bend the rules and do shoddy, hazardous work that endangers the public. Onsite, many sign professionals simply forget to follow common sense.

To avoid a harsh wake-up call from an electrical inspector — which could lead to red-tagging the project, hefty fines or follow-up costs — I have compiled the following checklist, which was inspired by Les Beros, an experienced, Canadian electrical inpector, who published a similar list in the Canadian Standards Assn. newsletter.

Advertisement

The following checklist doesn’t cover all requirements — just the ones I see frequently overlooked. It may seem incomplete to some readers and too pedantic to others. Points that are new to the 2005 NEC are marked as such. Check with your local AHJ to verify that the 2005 NEC applies to your neon installation before you prepare the blueprints.

First, mark the heading of each checklist with the project name and location, client, installation date, name of the installer and the responsible AHJ.

NEC Compliance Checklist
M = Mandatory
E = One of the designated conditions must be met
A = Mandatory in applicable situation

Power supply

* (M) If the sign is powered by incandescent or fluorescent lighting, it must employ a dedicated, 20-amp max branch. If it comprises neon, it must use a dedicated, 30-amp max branch.

* (M) The branch does not power any appliance besides the sign.

Advertisement

Means of disconnecting power

* (E) The disconnect must be in plain view of the sign; or

* (E) The disconnect must be lockable in the "Off" position; or

* (E) If the sign employs external controllers (i.e. clock, remote flasher), the disconnect is in direct sight or shares the controller’s enclosure. And, it disconnects the sign and controller, and is lockable in the off position.

* (M) The disconnect is clearly marked as belonging to the sign.

* (M) The disconnect does not operate any machines or appliances besides the sign.

Advertisement

Location and spacing

* (A) If the sign is installed over an active driveway, the sign’s base must afford clearance of at least 14 ft.

* (A) If the sign is accessible to pedestrians, it’s protected against damage.

* (A) If the sign is outdoors, it contains drain holes between 1/4- and 1/2-in. diameter at every low point.

* (A) There is a working space of 3 cu. ft. at each transformer installed outside the sign body.

* (A) When the sign’s installed in an attic or soffit, a walkway must access all transformers and each sign component.

Grounding

* (M) Every metal part of the sign larger than 2 in. is grounded (check with a continuity meter).

* (M) The conduit carries a listing mark (this also applies to flexible conduit).

* (A) If flexible, wet- or dry-location conduit exceeds 100 ft., an additional bonding conductor is used.

* (M) All bonding conductors are No. 14 or larger.

* (M) All bonding connections are secure.

* (M) All channel letters are bonded back to transformers.

* (A) Bonding connectors used when GTO is installed in rigid or flexible, nonmetallic conduit (rigid or flexible) are separated by at least 11/2 in. from the conduit.

* (A) The paint has been completely removed to assure bonding where the bonding jumper joins metal.

* (M) Bonding jumpers are not fastened with sheetmetal screws or a rivet without a washer.

Enclosures

* (A) The transformer box is listed for the purpose of sign illumination, or it comprises metal at least 0.02 in. thick if copper or aluminium, or 0.016 in. thick if steel.

* (M) Metal is protected from corrosion and, when exposed outdoors, is not mounted on a flat surface.

* (M) The enclosure is mounted in correct orientation.

* (M) The enclosure is rigidly fastened to a support structure.

* (A) Its location provides sufficient accessibility and a 3-cu.-ft. workspace minimum when outside the sign’s body.

* (A) The transformer enclosure is as close as possible to the neon tubing, and high-voltage wiring is kept to minimum length.

* (M) There is enough room for proper wiring and high-voltage spacings (11/2 in. from bare conductors for all but insulators).

* (M) There is a secure grounding/bonding connection.

* (M) The transformer box is not fastened to a suspended ceiling.

Transformers

* (M) The transformer is listed for its designated kind of service.

* (A) If the transformer is non-weatherproof and installed outdoors, it is mounted in a box.

* (M) The transformer is securely fastened in at least two points.

* (M) The transformer conforms to UL 2161 ground-fault protection, or is a PKBM model, or has an isolated secondary unit with less than 7,500V output.

* (M) The transformer’s primary, secondary and midpoint return conductors are correctly wired to appropriate terminals.

High-voltage wiring/raceways

* (M) Wiring is restricted to the minimum necessary length.

* (M) GTO is listed for transformer output voltage or higher.

* (A) The wiring comprises less than 20 ft. of metal conduit, or less than 50 ft. of nonmetallic conduit from the transformer to the first tube.

* (M) The conduit has a 1/2-in. or larger diameter.

* (A) The midpoint return is GTO in conduit.

* (A) The raceways are properly supported and fastened.

* (A) Raceways have sealed ends where they are exposed to wet conditions.

* (A) (New regulation) GTO insulation extends 21/2 in. or more beyond metal conduit or tubing in all locations.

* (M) Where exposed, all bare conductors are spaced at least 11/2 in. from any material besides insulation.

* (A) Joints and connectors are approved for the type of raceway used.

* (M) There is only one conductor per length of conduit or tubing.

Electrode connections

* (M) Electrode enclosures (boots, cups, etc.) are listed for the appropriate purpose (wet or dry installations) and are the correct size for electrodes and cables.

* (A) Boots and cups used in wet locations point downward.

* (A) If glass cups are used, they are fastened with clips.

* (M) The first neon-tube support is 6 in. or less from the electrode.

PK fittings

* (A) All components are listed.

* (A) When exposed outdoors, the tube bushing seal and the wall-to-PK seal are in place.

* (A) Water drainholes point downwards.

* (A) All PK fittings are properly bonded and grounded.

Section signs (New regulations)

* (M) All prefab sections carry a listing mark and label of the section number, and the total number of sections used in the sign.

* (M) If the field-installed wiring operates on more than 1,000V, all wiring must comply with all requirements.

* (M) Installation instructions are ready for the AHJ’s review before his final inspection of secondary wiring.

Class 2 power supplies (New regulations)

* (A) If the neon sign is powered by a Class 2, external, low-voltage power supply, the complete sign carries a listing mark or has received permission from the AHJ.

* (A) Specific installation instructions accompany the signs.

* (A) When using high-voltage transformers, high-voltage wiring regulations are met.

* (A) Bonding connectors are used when GTO is installed in rigid or flexible, nonmetallic conduit.