Electrical Enclosure Guide
Electrical enclosures are designed to house electrical controls, drives, instruments, and components in indoor or outdoor environments. They can provide protection from falling dirt, dust, water, ice, corrosive materials, and more. This guide focuses on selecting an enclosure for a frequency drive, though the general principles will apply for other components as well.
Your specific application requirements will determine what type of enclosure you will need to house your frequency drive. To ensure maximum product life of mounting a frequency drive in electrical enclosures, you must pay attention to the following:
- Physical size & cooling
- Enclosure material
- Enclosure rating (NEMA and IEC ratings)
- Finish & coating
TEMCo's Electrical Enclosures
Our NEMA 3R, wall mounted vented electrical enclosures provide protection from falling dirt, windblown dust, rain, snow, sleet, and external formation of ice.
- 0.075 Galvannealed Steel
- Black quarter turn latches and padlock wing knob
- Provisions for subpanel
- Doors open 180 degrees
- Concealed hinges
- Vented top hood with bug screen
- Top mounted fans
- Vented rain hood with filter kits in door
- Din Rail mounting provisions insdie top for installation of thermostat and terminals
- Oil resistant gasket
- Ground studs on door and body
- Mounting holes for optional mounting strips
- 3/8-16 grounding kit
- Subpanel mounting hardware
|Part Number||Dimensions (HxWxD, in.)||Fan Size||System CFM||Filter Qty.||Price|
|EE0001 »||29 x 24 x 12||6"||107||2||$637.80|
|EE0002 »||35 x 24 x 12||6"||107||2||$716.54|
|EE0003 »||41 x 24 x 12||6"||107||2||$813.7|
|EE0004 »||47 x 24 x 14||10"||300||2||$982.87|
|EE0005 »||53 x 36 x 16||10"||300||2||$1587.70|
|EE0006 »||65 x 36 x 16||10"||600||2||$1807.11|
Physical Size & Cooling
Physical Size: Match the size of your frequency drive to the size of the usable space within the enclosure.
Cooling: When a frequency drive is installed in a panel or a closed metallic box, adequate cooling is required to ensure that the temperature around it will not exceed the maximum temperature rating. Manufacturers often state the cooling airflow required for each model (often indicated by the CFM requirement, or cubic feet per minute). Make sure your enclosure's system CFM is at or above the drive's required CFM.
Many drives require that you leave a minimum free space around them, and this distance is indicated by the manufacturer's user manual.
When drives are installed side by side or top and bottom, maintain the minimum recommended distance. Deflect the hot air coming from the frequency drive below.
Do not install heat sensitive components immediately above the frequency drive.
Example - WEG CFW09 Variable Frequency Drives
The following dimensional constraints apply to the WEG CFW09 Variable Frequency Drive line. The image and charts show minimum amount of space you need between the different sides of the drive to prevent overheating and to ensure maximum life of the drive.
Recommended Free Spaces
|6A to 28A/220-230V
3.6A to 24A/380-480V
2.9A to 14A/500-600V
|40 (1.57)||30 (1.18)||50 (2)|
|45A to 130A/220-230V
30A to 142A/380-480V
22A to 79A/500-600V
|100 (4)||40 (1.57)||130 (5.12)|
|180A to 361A/380-480V
450A to 600A/380-480V
107A to 472A/500-690V
100A to 428A/660-690V
|150 (6)||55 (2.17)||250 (10)|
Dimensions and System CFM Requirements
|CFW09 Model||Frame Size||Dimensions
(H x W x D)
|6A to 13A/220-230V
3.6A to 9A/380-480V
|1||8.3 x 5.6 x 7.7||19||9||0.5|
|2.9 A to 14A/500-600V
16A to 28A/220-230V
13A to 24A/380-480V
|2||11.4 x 7.2 x 7.7||32||15||0.9|
|3||15.3 x 8.9 x 10.8||70||33||2|
38A and 45A/380-480V
22A to 32A/500-600V
|4||18.7 x 9.8 x 10.8||89||42||2.5|
|70A and 86A/220-230V
60A and 70A/380-480V
|5||21.6 x 13.2 x 10.8||117||55||3.3|
|105A and 130A/220-230V
86A and 105A/380-480V
|6||26.6 x 13.2 x 11.8||138||65||3.9|
|44A to 79A/500-600V||7||32.9 x 132 x 11.8|
|180A to 240A/380-480V
107A to 211A/500-690V
100A to 179A/660-690V
|38.4 x 16.1 x 14.6||265||125||7.5|
|312A and 361A/380-480V||9||39.4 x 27.5 x 19.3||852||402||24.1|
|450A to 600A/380-480V
247A to 472A/500-690V
225A to 428A/660-690V
|46.7 x 27.6 x 22.9||795||375||22.5|
Different enclosure materials offer varying degrees of protection. View some common types of enclosure materials below to see which one best suits your application.
Cold Rolled Steel (ASTM A366)
A low carbon, cold finished steel made by passing bar stock between a set of rolls.
Hot Rolled Steel (ASTM A569)
A low carbon, hot finished steel made by passing bar stock between a set of rolls at a temperature above the recrystallization temperature. Scale is removed by means of a hot, weak sulfuric acid bath. An oil film is applied afterward.
Galvanized Steel (ASTM A526)
Zinc-coated steel that provides corrosion resistance. Hot dip galvanizing is the most common method of applying zinc coating. Other methods include metal spraying and electrodeposition. Galvanizing protects against corrosion by serving as a sacrificial barrier and providing cathodic protection.
Galvannealed Steel (ASTM A525)
Steel which is zinc-coated on both sides. Designed to be used when painted. Typically hot dipped to A40 ad A60 designations. Corrosion resistant, excellent for paint, easy to weld. Combination of galvannealed steel and properly selected paint provides resistance to blistering and peeling.
Thermoset polyester reinforced with glass fiber, processed by injection molding, compression molding, pultrusion, and open molding. High impact resistance, superior range of temperature limits. Excellent dimension stability, electrical properties, chemical resistance, and moisture resistance.
High performance thermoplastic processed by injection molding. High impact resistance, wide temperature limits. Excellent wear and chemical resistance.
Stainless Steel (Type 304)
Highly corrosion resistant iron-based alloy that contains 18% to 20% chromium. Stainless steel is generally considered non-magnetic. It exhibits similar resistance attributes as fiberglass and is resistant to highly polar solvents, such as acetone.
Stainless Steel (Type 316/316L)
Type 316 provides improved corrosion resistance to that of other chrome-nickel steels. It is used in marine atmospheres and where there is exposure to chemical corrodents. It provides improved resistance to salt, some acids, and high temperatures. However, it has less resistance to sulfates and chlorine than Type 304 stainless steel.
Aluminum (Type 5052)
A lightweight metal that forms a natural oxide layer, which shields its surface from most corrosive elements. Type 5052 is the strongest non-heat treatable aluminum alloy.
High performance thermoplastic resin that is processed by injection molding or street extrusion. Features: High impact resistance with a wide range of temperature limits. Good dimensional stability and electrical properties.
High performance thermoplastic resin that is processed by injection molding. High impact resistance, wide range of temperature limits, good dimension stability. Excellent electrical properties, chemical resistance, and moisture resistance.
Zinc Die Casting
A zinc die cast is formed when molten zinc alloy is forced under high pressure into a steel die. Strong, economical, and often cast to the exact shape needed without additional machining. Non-ferrous, will not rust. Zinc is an abundant natural element which is mined and used in many applications.
Below are some common industry standards for enclosure ratings, but this is by no means an exhaustive list of NEMA or IEC standards. See which enclosure rating you need for your application.
Type 1 - Indoor use in areas where there are no unusual conditions. Prevents accidental contact with enclosure equipment and protects against falling dirt.
Type 3 and 3R - Indoor or outdoor use. Protects against falling dirt, rain, snow, sleet, windblown dust, and external formation of ice.
Type 3S - Outdoor use. Provides a degree of protection against windblown dust, windblown rain and sleet. External mechanisms remain operable while ice laden.
Type 4 - Indoor or outdoor use. Protects against windblown rain and dust, splashing or hose directed water, and external formation of ice.
Type 4X - Same as Type 4, with corrosion resistance.
Type 6P - Indoor or outdoor use. Protects against falling dirt, hose directed water, entry of water during prolonged submersion at a limited depth, and external formation of ice.
Type 12 - Indoor use. Protects against dust, falling dirt, dripping non-corrosive liquids, lint, fibers, external condensation of non-corrosive liquids, and light splashing of water.
Type 13 - Indoor use. Provides a degree of protection against dust, spraying of water, oil, and non-corrosive coolant.
IP 30 - Protects against incidental contact with wiring and components.
IP 32 - Protects against incidental contact with wiring and components and spraying water 60° from vertical.
IP 54 - Protects against dust penetration. Limited ingress permitted with no harmful penetration of dust. Protects against water spray from any direction.
IP 66 - Totally protected against dust penetration. Protected against strong jets of water.
Comparison of IEC and CSA, NEMA UL, and cUL Ratings
NEMA 250 and UL 50 specify requirements and test for the degree of protection against entry as well as environmental conditions such as falling dirt, ice, corrosion, oil, and coolants. IEC 60529 does not have such requirements. Caution is necessary when attempting to equate IEC and NEMA enclosure ratings, since there are no exact equivalents.
The IEC designation consists of the letters "IP," followed by two numerals. The first number indicates the degree of protection against solid foreign objects entering the enclosure. The second number indicates the degree of protection provided by the enclosure with respect to harmful ingress of water.
Enclosures are designed and manufactured for permanent floor or wall mounting. Our current set of frequency drive enclosures are designed for wall mounting. Unless securely mounted, many enclosures require stabilizing support. Take care to avoid severe impacts or shocks during storage, handling, and assembly. Enclosures should be mounted securely to structures that can completely support the weight of the enclosure and its components.
Finish & Coating
Finishes and coatings provide additional degrees of resistance and protection to electrical enclosures. View common finishes and coating performance characteristics below.
Epoxy Polyester Powder
Suitable for indoor or outdoor applications. Superior corrosion resistance, chemical resistance, weather protection, and resistance to scrapes and scratches.
Textured Polyester Powder
A powder finish with an irregular surface. Suitable for indoor or outdoor use. Offers superior corrosion resistance, chemical resistance, weather protection, and resistance to scrapes or scratches.
High Solids Finish
Suitable for interior or exterior applications. Corrosion resistant, solvent resistant, solvent free formula, and mar and chip resistant.
Coating Performance Characteristics
Environmental benefits of using high-solids and powder coated products: Solvent-free coatings enable compliance with changing environmental regulations by dramatically reducing emissions that occur when using solvent-based coatings, while at the same time providing a more dependable and durable product.
|Powder Coat||High Solids|
|Adhesion to C.R.S.||Excellent||Good||Excellent|
|Direct Impact||60-160 in-lbs.|
|Salt Spray||> 800 hours||> 600 hours||> 800 hours||> 600 hours|
|Humidity||> 1000 hours|
|MEK||Dull Gloss||Little Effect||No Effect||Dull Gloss|
|Xylene||No Effect||Little Effect||No Effect|
|Automotive Fluid Resistance, 16 Hour Immersion|
|Gasohol||Swells||Little Effect||No Effect||Little Effect||No Effect|
|Brake Fluid||Blisters||Dull Gloss||Blisters||Dull Gloss|
|Motor Oil||Swells||No Effect|
Our stock enclosures can be easily recoated. To ensure good adhesion, sand all surfaces with 360 or 400 grit sandpaper. Wet wipe all surfaces with Alphatic Solvent or detergent wash. Always follow instructions provided by your paint manufacturer. Surface must be dry and free of oil, dust, dirt, or any other foreign substances between recoating. To avoid discoloration of Alkyd finishes, do not baked over 250°F.
Compatible paints are: All industrial enamel, acrylic enamel, and epoxy. For any other type of paint, check with your paint manufacturer to be sure that the paint is compatible with the paint on the enclosure.
Unless otherwise specified, our enclosures are finished with either an epoxy polyester powder coat or a high solids recoatable finish over phosphatized surfaces. These finishes will provide ordinary protection against corrosion in average industrial indoor areas. Special materials and finishes are available for outdoor use or special environments upon request.