Enclosures
HPS products are available in Type 1, 2, 3R, 3RE, 3RX, 4, and 4X enclosures. See detailed description of enclosure types below.
Not all product lines or kVA sizes are compatible with all enclosure types. Please use the E-Quotes Lite product configurator to determine which options are most commonly available.
Comparison of Enclosure Types for Indoor and Outdoor Non-Hazardous Locations
Indoor | Indoor/Outdoor | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
CSA C22.2 No 94.2 Enclosure Type | 1a | 2a | 5 | 12 | 12K | 13 | 3 | - | 3Ra | - | - | 3S | - | 4 | 4X | |
NEMA 250 Enclosure Type | 1a | 2a | 5 | 12 | 12K | 13 | 3 | 3X | 3Ra | 3REf | 3RXa | 3S | 3SX | 4 | 4X | |
Equivalent IEC 60529 IP designation | IP20 | IP22 | IP53 | IP54 | IP54 | IP54 | IP55 | IP55 | IP24 | IP24 | IP24 | IP55 | IP55 | IP66 | IP66 | |
Provides a degree of protection against these environmental conditions |
Accidental contact with live parts | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X |
Falling dirt | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | |
Dripping and light splashing of non-corrosive liquids |
X | X | X | X | X | X | X | X | X | X | X | X | X | X | ||
Circulating dust, lint, fibers and flyings |
X | X | X | X | X | X | X | X | X | |||||||
Settlingd dust, lint, fibers and flyingsd | X | X | X | X | X | X | X | X | X | X | ||||||
Wind-blown dust | X | X | X | X | X | X | ||||||||||
Rain, snow, and external formation of ice or sleetb | X | X | X | X | X | X | X | X | X | |||||||
Horizontal blowing rain, snow or sleet | X | |||||||||||||||
External formation of ice or sleetc | X | X | ||||||||||||||
Hose down and splashing water | X | X | ||||||||||||||
Corrosion | X | X | X | X | ||||||||||||
Oil and coolant seepage | X | X | X | |||||||||||||
Oil and coolant seepage, spraying and splashing | X |
Notes
a - These enclosures may be ventilated
b - External operating mechanism(s) is not required to operate when the enclosure is ice covered
c - External operating mechanism(s) shall be operable when the enclosure is ice covered
d - These fibers are flyings are non-hazardous and are not considered Class III type ignitable fibers or combustible flyings
e - Since IEC 60529 does not specify degrees of protection for many conditions considered within CSA C22.2 No. 94.5, the IEC classifications cannot be exactly equated to North American Type numbers. the North American Type numbers meet or exceed the test requirements for the associated IP classifications. This table cannot be used to convert from IEC classifications to North American Type designations.
References: CSA C22.2 No. 94.2, CSA C22.1 (CEC), NEMA 250, NEMA document - NEMA Enclosure Types
Disclaimer: This table is for reference purposes only. Please refer to appropriate standard for enclosure selection to meet your application specifications.
Enclosure Types

TYPE 3R
This is a general purpose ventilated enclosure constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against the ingress of solid foreign objects (falling dirt); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and that will be undamaged by the external formation of ice on the enclosure.
Transformer Enclosure Accessories
Rodent Kit
Ensure the safe operation of your transformer by protecting from unwanted visitors with the optional rodent kit. Rodent kits are available for DH1-DH10 Type 3R enclosures.
Grounding Kit
For applications requiring more than one ground connection, HPS offers an optional grounding kit. The grounding kit is available for DH1-DH10 Type 3R enclosures.

TYPE 3RE
This is a general purpose ventilated enclosure constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against the ingress of solid foreign objects (falling dirt and circulating dust); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, circulating snow); and that will be undamaged by the external formation of ice on the enclosure.
Medium Voltage 3RE Enclosure Enhancements
Easy Installation and Filter Replacement: Our kit makes it a breeze to install and change filters, even while your transformer is up and running.
Snow and Rain Resilience Solution: We've put our kit through rigorous tests, passing with flying colors. It withstood wind speeds of up to 120 km/h, handling snow particles as small as 350 microns. (Note: The typical snowflake size is 500 microns*.) Plus, it aced the rain test at 130 km/h with a water discharge rate of 7.5 GPM. With this level of durability, your transformer is prepared for certain hurricane-level conditions.
Enhanced Outdoor Application Solution: As outdoor transformers face new challenges with the rise of EV charging, renewables etc. our 3RE kit is designed with enhanced features to meet these demands effectively.
Retrofit Efficiency Solution: Our retrofit-friendly design solution allows you to effortlessly upgrade your standard 3R enclosure to the robust 3RE, enhancing protection, reducing lead times, and generating cost savings for your existing designs.
Note: While our kit is designed to withstand severe weather conditions, it may not withstand all hurricane-level situations. We recommend consulting with our experts to ensure proper protection for your specific needs. Your safety is our priority.
*As per Environment Canada, the average size of snow flake is 500 microns.




TYPE 4
This is a general purpose non-ventilated enclosure constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against the ingress of solid foreign objects (falling dirt and circulating dust); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, circulating snow); and that will be undamaged by the external formation of ice on the enclosure.

TYPE 4X
This is a general purpose non-ventilated enclosure constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against the ingress of solid foreign objects (windblown dust); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow, splashing water, and hose directed water); that provides an additional level of protection against corrosion; and that will be undamaged by the external formation of ice on the enclosure. (Note: not submersible). Please see our TENV product options here.

TYPE 12
This is a general purpose non-ventilated enclosure constructed (without knockouts) for indoor use only to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against the ingress of solid foreign objects (falling dirt and circulating dust, lint, fibers, and filings); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing). (Note: not submersible).