What does the 2020 NEC say about adding retrofit lighting kits?

By: Robert Key | Nov 03, 2021

Lighting retrofit kits are immensely popular, due to the availability of high-efficiency lighting options that can reduce power consumption quite drastically. The 2020 edition of the National Electrical Code (NEC) has added a new Section to help us deal with these kits, Section 600.35 

What are the important things for the installer and inspector to look for in such an installation?  

First and foremost are the manufacturer’s installation instructions. These govern the installation of these listed and labeled lighting retrofit kits even more than the code itself. For example, the general instructions found at Section 600.35 says these kits “shall include installation instructions and requirements for field conversion of the host sign.” The installation instructions will govern most of the installation. These must also be present for the inspector’s use so that proper installation can be verified.  

What wiring methods can be used for these retrofit kits? Again, the manufacturer installation instructions must be followed if they specify a particular wiring method, but otherwise they can be wired in accordance with NEC Chapter 3. But what if the load is being supplied by a class two power source? 

  • If the transformer is internal to the sign, then any wiring method that complies with chapter 3 can be used up to the point of the transformer.  
  • If the load side wiring of the transformer extends outside the sign, then Tables 600.33 (A)(a) and 600.33(A)(b) apply. Table 600.33(A)(a) specifies which type of cable can be used in a given location or environment. For example, for class 2 wiring in wet locations, the only cable that is permitted to be used is PLTC, or Power Limited tray cable. 
  • Table 600.33(A)(b) dictates what substitutions are permitted to be used. For example, if the location calls for a CL2P wiring method, then CL3P can be substituted. The only cable for which there is no substitution is PLTC.  
  • If the wiring method is exposed to direct sunlight, then it must be listed for such a use, except for PLTC, which does not have to be labeled as sunlight resistant.  

 What else is stipulated in addition to the wiring methods? When the sign is disassembled, all parts of the installation not being replaced by the retrofit kit must be inspected. What is required if there are damaged parts discovered upon disassembly of the sign? In that case damaged parts must be replaced or repaired to maintain the dry, damp, or wet rating of the sign or system. Retrofitted signs must also be marked per Section 600.4(B), a new code sub-section for retrofit kits.  

 The 2020 NEC provides comprehensive instructions for installing retrofit sign kits, the guidelines that the installer and AHJ need to be familiar with. Taking time to familiarize yourself with these new sections of the Code will help you to provide a compliant installation, which will protect the end user and save time. 


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