How to choose an electrical enclosure: understand IP codes, compare metal vs plastic, size for heat and components, and read the procurement checklist.
An electrical enclosure is the metal or plastic shell that houses circuit breakers, contactors, terminals, power supplies and wiring inside a control panel or distribution board. Its job is threefold: keep people away from live parts, shield the equipment from dust, water, oil and impact, and give the installer a structured frame to mount components on DIN rails or plates. A wrong choice does not fail loudly — it corrodes, overheats or lets water in months after commissioning. This guide walks procurement officers and panel builders through the three decisions that actually matter: ingress protection, material, and size.
The IP (Ingress Protection) code is defined by IEC 60529. The first digit covers solids, including fingers and dust; the second covers liquids. A common mistake is specifying “IP65” by habit without checking the spray angle the equipment will actually face.
| Code | Solid protection | Liquid protection | Typical use |
|---|---|---|---|
| IP54 | Dust limited | Splashing water | Indoor control panels |
| IP65 | Dust tight | Low-pressure jet, any direction | Factory floors, washdown areas |
| IP66 | Dust tight | High-pressure jet | Outdoor, hosedown |
| IP67 | Dust tight | Immersion 1 m / 30 min | Near pumps, temporary submersion |
For most outdoor installations a distribution box rated IP65 or IP66 is enough; only sites with jet washing or temporary flooding need IP67.
Both materials meet the same IP tests, so the decision is about environment and EMC, not waterproofing.
| Factor | Steel / Stainless | ABS / Polycarbonate |
|---|---|---|
| Corrosion | Stainless best outdoors; painted steel needs care | Excellent, no rust, UV-stabilised grades |
| EMC shielding | Inherent, good for noisy drives | Poor unless coated; add EMC plate |
| Weight | Heavy, needs strong wall fixings | Light, easy to install |
| Cost | Higher | Lower |
| Best for | Harsh, corrosive, high-EMC sites | Indoor, light outdoor, budget builds |
Rule of thumb: choose stainless steel for coastal, chemical or food plants; pick a UV-stabilised plastic enclosure for general outdoor and indoor use where EMC is not critical.
Undersized boxes overheat and are impossible to wire. Size from the inside out:
Specify compliance with IEC 62208 (empty enclosures for low-voltage switchgear) and IEC 60529 (IP codes). For public or industrial sites, also note the IK impact rating: IK08 resists 5 J, IK10 resists 20 J — relevant where panels can be struck. Quoting the standard on the PO turns a vague “waterproof box” into an auditable specification your supplier must meet.
Both are dust-tight. IP65 survives a 6.3 mm low-pressure water jet from any direction; IP66 survives a 12.5 mm high-pressure jet. Choose IP66 where equipment is hosed down or exposed to strong spray, and IP65 for splashing and light jetting.
For coastal, chemical or food environments use stainless steel. For most other outdoor and indoor sites a UV-stabilised plastic (ABS or polycarbonate) enclosure is lighter, cheaper and rust-free. Pick metal when electromagnetic shielding is required.
Sum the DIN-rail width of all devices in 18 mm modules, add 20–30 % spare, confirm the deepest device fits the depth, and budget at least 50 mm top and bottom for cables. If total heat loss exceeds about 50 W, plan active cooling.
IK measures impact resistance (IEC 62262). IK08 withstands 5 J and IK10 withstands 20 J of impact. It matters for panels in public, industrial or vehicle-adjacent locations where the box could be struck.
Yes, provided it carries a suitable IP rating (IP65 or higher), is UV-stabilised for plastic models, and is mounted under a canopy or on a shaded wall away from direct jet washing. Always seal cable entries with proper glands.
Send the ratings, dimensions and quantities you are working to and we will confirm the closest match from the ELEHPD catalogue, the compliance documents available for it and the lead time. OEM branding, private model numbering and buyer-specific cartons are available on qualified volumes.