Any listing in this product directory or other related materials, where “NRTL” appears next to the product name was tested and is listed by ARL as an NRTL, consistent with the requirements of the NRTL Directive.  Other products are listed solely by ARL under its accreditation to ISO 17025 and ISO 17026.


The products listed here are air-cooled transformers and reactors for general use; ignition transformers for use with gas burners and oil burners; and gas tube sign transformers for use with inert gas tubes.  Transformers incorporating over current or over temperature protective devices, transient voltage surge protectors, or power factor correction capacitors are also covered by the requirements for this category of products.

These requirements for this category do not cover liquid immersed transformers, variable voltage autotransformers, transformers having a nominal primary rating of more than 600 volts, transformers having over voltage taps rated over 660 volts, cord and plug connected transformers (other than gas tube sign transformers), garden light transformers, voltage regulators, swimming pool and spa transformers, or other special types of transformers covered in requirements for other electrical devices or appliances.  In addition, not covered are:

a)            Autotransformers used in industrial control equipment;

b)            Class 2 or Class 3 transformers;

c)            Toy transformers;

d)            Transformers for use with radio and television type appliances;

e)            Transformers for use with high intensity discharge lamps;

f)            Transformers for use with fluorescent lamps;

g)            Ventilated transformers for general use or non-ventilated transformers for general use (other than compound filled or exposed core types);

h)            Dry type distribution transformers rated over 600 volts;

i)            Transformers incorporating rectifying or wave shaping circuitry; and

j)            Transformers of the direct plug-in type;

Each product is marked with the name or trademark of the (manufacturer) or vendor, a distinctive style, type, catalog or model designation, electrical ratings, percent impedance, environmental type, temperature class, wiring diagram, electrical hazard and cautionary warnings, installation warnings, date code, and other markings as required for specific transformer types and applications.

These products comply with ARL requirements which include pertinent sections of the Standard for Safety, ANSI/UL 506, Specialty Transformers, and are intended to be employed in accordance with the National Electrical Code, ANSI/NFPA 70.

A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements of the standard, and that involve a risk of fire, electric shock, or injury to persons, have been evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of the standard.  A product whose features, characteristics, components, materials, or systems conflict with specific provisions of the standard have been judged to be in non-compliance with the standard.

Only products which properly bear the ARL Listing Mark (Label) are considered Listed by ARL.


Delisted products appear with a double strike through and “DELISTED” after the report number.
Deleted/revised models for listed products appear with a single strike through.



Listed Product Directory (revised 01.13.15)