Neon Transformers and Power Supplies

UL 2161

1 Scope

1.1 This standard applies to transformers and power supplies, including those intended to be connected to a Class 2 source of supply, that provide the voltage and ballasting for neon and cold-cathode tubing (electric-discharge tubing) consisting of electrodes and gas such as neon, mercury, helium, argon, and similar gases, enclosed in glass. Neon transformers and power supplies for use in signs and outline lighting are intended to be used in accordance with Article 600 of the National Electrical Code, NFPA 70. Cold-cathode supplies identified for use only in cold-cathode lighting systems are intended to be used in accordance with Article 410 of the National Electrical Code.

1.1 revised July 14, 1999

1.2 Neon transformers and power supplies covered by this standard are designated by their construction and intended use as specified in Table 1.1.

1.2 revised March 16, 1999

1.2.1 The following neon supplies are only covered as components for use in an end product that is determined to comply with the Standard for Electric Signs, UL 48:

a)    Type 1 neon supplies;

b)    Types 5 and 6 neon supplies when complying with Exception No. 3 to 20.1;

c)    Types 6, 7, and 8 neon supplies when complying with the Exception to 11.4.1 or the Exception to 11.4.3;

d)    All types of neon supplies having an isolated output when complying with Exception No. 2 to 20.1; and

e)     Cold-cathode supplies when complying with Exception No. 5 to 20.1.


1.2.1 revised July 10, 2002

1.3 These requirements do not cover transformers or power supplies intended to supply other forms of electric-discharge lighting sources such as fluorescent and high-intensity-discharge lighting. Requirements for fluorescent supply sources are covered in the Standard for Fluorescent-Lamp Ballasts, UL 935, and the requirements for high-intensity-discharge lighting supply sources are covered in the Standard for High-Intensity-Discharge Lamp Ballasts, UL 1029.

1.4 These requirements do not cover transformers or power supplies that are intended for use with oil burners. The requirements for oil ignition transformers are covered in the Standard for Low Voltage Transformers - Part 1: General Requirements, UL 5085-1 and the Standard for Low Voltage Transformers - Part 2: General Purpose Transformers, UL 5085-2, and for oil ignition power supplies are covered in the Standard for Power Units Other Than Class 2, UL 1012.

1.4 revised December 29, 2009
Table 1.1Construction type designation
Core and/or circuitry Primary connections Secondary connections Type designa-tions
Completely encloseda Any part exposedb Wiring terminals or leads Power supply cord Wiring terminals or leads Inte-gral recep-tacles Type designa-tion number - see numbered footnotes for definition
Exposed - not in wiring compartment or through conduit fitting Unexposed - in wiring compartment or through conduit fitting Exposed - not in wiring compartment or through conduit fitting Unexposed - in wiring compartment or through conduit fitting
no yes yes no no yes no no 1
yes no yes no no yes no no 2
yes no no yes no yes no no 3
yes no no yes no no yes no 4
yes no no yes no no no yes 5
yes no no no yes no no yes 6
yes no no no yes yes no no 7
yes no no no yes no yes no 8
a - Enclosed is the containment of electrical parts in a material that complies with 4.1.
b - Exposed is any current carrying part other than input and output leads or terminals that is not contained in accordance with 4.1.
Type 1 - Open core-and-coil transformer or open power supply that requires a complete enclosure in the end product.
Type 2 - Neon supply with the input and output terminals, leads, and connections enclosed in the end product.
Type 3 - Neon supply with input leads or terminals enclosed and intended for connection to a permanent wiring system, and with secondary leads or terminals required to be enclosed in the end product.
Type 4 - Neon supply that is fully enclosed including the output and is intended for connection to a permanent wiring system.
Type 5 - Neon supply that is fully enclosed and intended for connection to a permanent wiring system, and is provided with integral output receptacles.
Type 6 - Cord-connected neon supply provided with integral output receptacles.
Type 7 - Cord-connected neon supply with secondary output leads or terminals needing to be enclosed in the end product.
Type 8 - Cord-connected neon supply with enclosed output leads or terminals.

1.5 Deleted July 10, 2002