Print Page   |   Contact Us   |   Sign In   |   Join
IAEI Magazine
Blog Home All Blogs
Search all posts for:   


View all (1101) posts »

When is a sign not just a sign?

Posted By Rick Hollander, Monday, March 01, 2010
Updated: Wednesday, January 23, 2013

Today’s demand for attention has brought on the need for signs to be more than just a display. Theses signs are designed for the potential customer to notice them and come in to check out the establishment. The sign might be portraying a message. Or it could be a show in itself. Let me take you on a quick step-by-step tour to inspecting signs.

Be aware of the codes

First, we inspectors need to be aware of the codes that affect the installation of signs (NEC Article 600), but also we might have other issues involved. Locally, one of the sign shops was contracted to recreate a theater marquee (see figures 1 and 2). This now incorporated some unique design criteria—such as luminaires, controllers, fluorescent cabinets, neon power supplies, and display lamps—and included compliance with additional code articles.

Is the sign listed?

Let us start with Article 600. First, is the sign listed per 600.3? Check to see if your local sign shop is maintaining its listing status with a nationally recognized testing laboratory (NRTL). Is there a marking label per 600.4? Labels need to have the manufacturer’s name, trademark, or other means of identification in addition to input voltage and current rating (see figure 3). Is the circuit rated at least 20 amperes as required by 600.5? This sign circuit can serve no other loads. Many times the circuit was installed by an electrician who is not familiar with Article 600. He attempts to use the first or closest junction box or luminaire to connect the sign to. Is the sign branch circuit identified on the panelboard circuit directly per the requirements of 408.4? Is the sign branch circuit legible and distinguishable from all others? As an example, "EXIT SIGN” can be an exterior sign or an exit sign. Do we have a disconnecting means within sight of the sign as required by 600.6? As you are looking at the sign, which is the display of letters or words, the disconnecting means (switch) should be visible. If the disconnecting means is on the other side of the wall or parapet, it is "not within sight of” the sign. The switch is to be capable of being locked in the open position. A circuit breaker lock-out may also be used (see figures 4, 5, and 6).

Photo 1. Rialto theater marquee lighted
Photo 2. A marking label per NEC 600.4
Photo 3. Swatches
Photo 4. Lock-out device

Check both grounding and bonding

Grounding! This can be a whole other subject. Section 600.7 is where we look for grounding requirements for the sign, but don’t forget Article 250. Is that enclosure or raceway bonded? Section 250.148 reminds us that if circuit conductors are spliced, we need to bond the metal enclosure to the equipment grounding conductor. Do we have a good connection for our bonding connection to the power supply cabinet under the painted surface? No! Check to see if we have a good connection, i.e., no sheet metal thread screws, clean surface [250.8, 250.12, and 250.102(B)]. Remember we want to create a permanent, low-impedance path for ground-fault current.

Check the wiring methods

All right, now to the power being supplied… Are the wiring methods approved in accordance with NEC Chapter 3, Wiring Methods and Materials? Are the fittings installed per their listing and are they tight? Loose fittings do not maintain continuity. Is the method supported correctly? You need to check Chapter 3 wiring method articles for the correct supporting requirements as to the wiring methods used.

Where is the power supply?

Ok, let’s move on. Where is the power supply located (see 600.21)? The particular sign we discussed earlier had access panels close to each power supply and to other electrical components. If not, how do we access this equipment? Our location is to have an access door (3 ft by 2 ft), and a walkway at least 1 ft wide from opening to equipment. We need to see what we are doing when we are working. Sections 210.70(C) and 600.21(E) tell us that equipment requiring servicing needs a lighting outlet switched at the point of entry.

Controllers can serve different functions

The controller is also covered under 600.6(A)(2) and (B) (see figure 7). This section gives the location for the controller disconnecting means (switch). Also, this switch (if not within sight of the controller) shall be capable of being locked in the open position. These controllers can serve different functions, such as servicing the neon letters and the rolling lamps under or around the sign.

Now let’s look at how we tell the controller what functions to perform. In most cases, there is a data cable running from an office with a programming unit (see figure 7). We will need to look at Article 725 to find the code requirements for this installation. First, we need to determine what Class power supply we have. In this case, we have a Class 2 as described in 725.121(A)(1) or (2). Do any other sections such as in 725.3 apply? Most of the time, we will reference the wiring methods of Article 300 based on 725.130(A) and (B), but we need to make sure the method is secured in a neat and workmanlike manner (725.24) if the cable is not in a raceway. And, lastly, with this equipment, is it listed as per 110.3?


Photo 5. Lock-out device — Note: Portable means for adding a lock to the switch or circuit breaker is no longer permitted.

Photo 6. Lock-out device


Tubing installation methods

In most jurisdictions, the skeletal tubing might be considered field-installed and fall under Part II of Article 600. You now need to look at the tubing installation methods. The secondary circuit conductors need to be installed using 600.32 (over 1000 volts). Pay attention to 600.32(A)(4) for spacing from grounded parts; the distance should be at least 1½ in. When the cable to glass connection is exposed to the weather, make sure that you have 2½ in. from exiting the raceway to the connection of cable as stated in 600.32(G). Also the cable and connection boots need to be listed for a wet location [see 110.3 and 600.42(F)]. If glass electrode housings or metal flanged receptacles (PK housings) are used, check for the listed housing cap [see 600.42(G) and figure 8]. Did you remember to check for the ¼ in. clearance of the glass tubing to any grounded surface [see 600.41(C)]?

Fluorescent cabinet

For the fluorescent cabinet used for the marquee message, is the switch connected to the main switch or is it separate for the cabinet only? The switch still falls under the guidelines of 600.6. Switches need to be externally operable from the cabinet. While checking the power connection in the switch junction box, make sure the box is grounded per 250.148.

Recessed luminaires

Now what other electrical equipment will concern us? Recessed luminaires, as outlined in Parts XI and XII of Article 410. We need to check the supporting of the luminaries and wiring methods [see 410.30(A), 410.116, 410.117 and 410.118 and for illustration, see figure 9]. The recessed cans need to be secured to the frame of the sign body by an approved method acceptable with your AHJ. Clearances (depending on the material of the sign body) must be maintained. If the sign is outdoor and exposed to high heat, the conductor insulation must be suitable for the temperatures encountered and not in excess of 90ºC (194ºF).

Photo 7. Weatherproof boots

In closing, we have looked at some of the aspects of inspecting a typical sign. Sign inspections do not need to be difficult, just remember the basics. NEC requirements are the minimum requirements. Listed materials and components are available. Use listed products as intended. Signs are to be on their own circuits. Switches need to be within sight of the sign body, or capable of being locked out. Grounding, regardless of the voltage, needs to be maintained. After the basics check, see if you have other factors such as data connections, controllers to operate additional functions, luminaires attached to your sign, or skeletal neon tubing on the sign. With high voltages come increased hazards and concerns. Inspectors and installers should work together to achieve code-compliance and safe installations. Communication and education are the keys. You need to understand the basics; then use references to help you with the rest, a good example would beNeon Lighting, A Professional Advantagefrom IAEI.

Photo 8. Inside the sign — Always verify that all wiring methods are properly terminated and secured.


Table 1

Read more by Rick Hollander

Tags:  Featured  March-April 2010 

Share |
Permalink | Comments (0)