7 Compliance Tips for Electrical Enclosure Air Conditioners & Other Cooling Methods


Enclosure air conditioners for use in the U.S. or Canada is required to meet certain safety standards. Although legal requirements governing the use of electrical equipment appear complex, certain compliance requirements are clear and universally applicable for electrical enclosure cooling equipment. The following seven compliance tips will help you ensure that your enclosure cooling systems comply with requirements.


In the U.S., the Occupational Safety and Health Administration (OSHA) governs safety and health within the workplace. In 1971 the National Electric Code (NEC) was incorporated within the Construction Safety and Health Standards of OSHA. It’s therefore necessary that all electrical equipment conforms to the safety requirements of OSHA and the NEC.

Authority Having Jurisdiction

Within local authorities, the Authority Having Jurisdiction (AHJ) is responsible for enforcing local building codes and ensuring compliance. Many local authorities’ codes are based on the NEC, also known as the NFPA 70, but others add local addendums or use their own specific codes.

In all cases, before an installation can be energized the installation must be signed off by a local inspector mandated by the AHJ.

Nationally Recognized Testing Laboratories

The means of ensuring that electrical equipment conforms to the relevant codes is for the equipment to be certified by a Nationally Recognized Testing Laboratory (NRTL), and this certification will be accepted by the AHJ. There are more than a dozen NRTLs licensed in the U.S. but the most well-known are UL and CSA.

Before selecting enclosure cooling equipment, always make sure that the equipment has been certified and carries the NRTL certification mark.

Canadian Requirements

Enclosure cooling systems sold in Canada must conform with the Canadian Electrical Code Part 1. In Canada, the Canadian Standards Association (CSA) and certain other testing laboratories such as UL are accredited. In order to distinguish between American and Canadian certifications, Laboratories such as UL use a prefix C next to their mark; when written, UL refers to the U.S. and cUL to Canada. It’s important to understand this difference so as to avoid the possibility of installing equipment with the incorrect certification for your region.

Hazardous Areas

Equipment designed for use in a hazardous area must also be certified as such. Take care to ensure your enclosure cooler conforms to the specific hazardous area rating applicable and that it is compatible with the rating of the enclosure to which it is attached.

NEMA Enclosure Ratings

The enclosure cooling system adopted must have the same or superior NEMA enclosure rating as the electrical enclosure to which it is attached. If the enclosure is ventilated, the enclosure cooling system is restricted to the use of fans and filters. A closed loop enclosure air conditioner or cooler should be used if the enclosure is sealed.

CE Mark Not Accepted

The CE mark is a European mark only and does not comply with American or Canadian requirements. Electrical equipment for use in the U.S. must carry a mark from an American certified NRTL. However, it is not uncommon to find products that carry both UL and CE marks, in which case these products can be used in both regions.

Verify Before You Buy

It’s essential that you verify before you purchase, that enclosure cooling systems for use in a particular region or area conform to the statutory requirements for that territory. In the U.S. and Canada, it is mandatory for certain equipment to carry the mark of an approved testing laboratory, and an enclosure air conditioner falls within those requirements. Be safe and only buy certified equipment.

Thermal Edge

Thermal edge is one of the leading manufacturers of enclosure cooling systems. Our products comply with U.S. and Canadian standards: we have UL certification for both countries as well the European CE mark. Our products include ventilation systems for cooling enclosures, closed loop air-to-air heat exchangers, and a full range of enclosure air conditioner models. We also have models rated for hazardous areas. Call us now at 888.580.0202 or contact our sales representatives to discover how Thermal Edge can solve your enclosure cooling problems.