Electrical enclosure FAQs, expert answers

Yes, a ventilation system can be fitted inside an electrical enclosure, including as a retrofit to an existing installation. Our Air-Technology setup is integrated automatically in our AK range of distributors and is also available for other enclosures. It uses air exchangers that transport condensate out of the enclosure while allowing the interior air to mix constantly with the environmental air. Ventilation elements prevent condensation forming and building up, reduce the risk of overheating, and protect the electrical equipment within, meeting IP65 requirements.

A ventilation system is worth fitting where an enclosure faces damp conditions, fluctuating temperatures, or houses many components in a small space — all situations that cause condensation or overheating. Promoting air circulation reduces condensation risk while maintaining ingress protection. Our AK range uses registered Air-Technology, which delivers a high air exchange rate with pressure equalisation to prevent condensation and excessive heat, while protecting circuits from water, dust and foreign particles in line with IP65.

For marine vessels and other offshore installations, our most suitable solutions are the TK PC, Abox-i PC and Abox-i SL ranges. These are DNV certified, meaning they comply with the world's leading classification society for the maritime industry. They offer up to IP 66 ingress protection, preventing water and dust from entering the system, and they are made of polycarbonate, so they withstand exposure to UV light and extreme weather conditions. They are also highly resistant to mechanical stress.

An enclosure can be submerged if it carries an ingress protection rating of IP68, which means it resists prolonged immersion in at least one metre of water. The most cost-effective and reliable way to achieve this is to fill the enclosure with silicone or resin, which prevents moisture reaching the internals. Our Abox XT junction boxes use this method and withstand submersion in up to 10 metres of water. Each box is supplied with a cast resin bag and a funnel, and has two holes, one to pour the resin in and one to let the air out.

An enclosure can be submerged if it is rated IP68, which gives resistance to prolonged water immersion at depths of up to 3 metres. Sealing the inside with resin is more cost-effective and reliable than specifying individual water-resistant components, and it protects the internal parts from moisture penetration. Our Abox XT junction boxes use cast resin and comply with DIN EN 60670 and DIN EN 60529. The Abox Pro XT model withstands ambient temperatures from -35°C to 80°C, has an IK08 impact resistance rating, and is available with WAGO screwless clamping technology.

For demanding outdoor applications we recommend our GEOS range. GEOS enclosures are designed specifically for outdoor use, offering excellent protection against UV radiation, rain and extreme temperatures ranging from -35°C to 80°C, and they are resistant to corrosion and chemicals, which makes them suitable for industrial or coastal environments. The range also has a high IK09 impact rating, so it can handle mechanical shocks and heavy use without cracking or compromising the safety of the equipment inside. That durability is tested in our UL-certified lab against international standards including EN 62262 for impact resistance.

Outdoor enclosures can protect solar components from UV damage, provided the enclosure itself is built for it. Our GEOS range uses high-grade polycarbonate for improved protection against UV radiation, corrosion and other environmental damage, and every model is certified to multiple international standards. GEOS enclosures carry IP66 or IP67 ratings, making them dust-proof and resistant to powerful water jets, or suitable where temporary immersion of up to 30 minutes in one metre of water is likely, and they have an IK09 impact rating. They withstand -40°C to +80°C and can incorporate BEL Air M40 ventilation to prevent condensation and pressure building up without affecting the IP rating.

For harsh outdoor conditions where an enclosure is also at risk of being knocked, we recommend our GEOS series. GEOS enclosures tolerate temperatures from -35°C to 80°C, as well as a 24-hour ambient temperature of up to 60°C, and they resist corrosion, chemicals and prolonged exposure to UV rays. They also carry an IK09 impact rating, which means they have been tested to withstand substantial mechanical stress, and we carry out that IK impact testing in our own laboratory using controlled impacts from multiple angles.

To protect electrical equipment from rough environments, vandalism or other mechanical impacts, look for a high impact protection, or IK, rating. IK is a 00 to 10 code system defined by the DIN EN 50102 (VDE 0470-100) standards. The lowest values mean the product offers limited to no resistance to impact energy, while IK10 means the enclosure is protected against 20 joule impacts, equivalent to a 5 kg mass dropped from 400 mm above the impacted surface. The North American equivalent is f1 or f2 certification to UL 746C. We offer enclosures from IK05 to IK10.

For urban environmental monitoring, our GEOS range is designed for this kind of outdoor installation. GEOS enclosures are rated IP66 for protection against dust and water jets, and IK09 for high impact resistance, which matters in public spaces where vandalism is a concern. They are made from materials that withstand the corrosive effects of urban pollution. GEOS can also be fitted with partition walls, so each sensor has its own designated space and crosstalk between devices is avoided.

Yes. The enclosures in our IBT range, designed for use in concrete constructions, are made from polypropylene copolymer (PPC) and are fully recyclable. PPC is classed as plastic type 5 under the Resin Identification/Plastic Recycling Code, withstands four closed loops of recycling and suits both mechanical and chemical processing. It is also lightweight compared with other plastics, which makes it well suited to concrete applications. The range spans a spread of ingress protection, from IBT Precon junction boxes at IP30 to universal installation housing rated to IPX4, and includes protection class II rated junction boxes where safe electrical separation is required.

For electrical installations in pre-cast and cast-in-place concrete, we recommend our IBT range, which has been developed specifically for these applications and tried and tested over many construction projects. Available in different sizes and shapes, IBT enclosures have a robust, highly stable design that performs when the concrete is both wet and dry. The technology prevents the enclosure being crushed under the weight of the concrete, a patented diaphragm sealing system prevents displacement or infiltration as concrete is poured, and a patented support spar mounts the box to vertical or horizontal formwork.

Yes. Our IBT range of electrical enclosures is made from fully recyclable plastic, specifically polypropylene (PP) copolymer. We selected it because it offers great flexibility when it comes to recycling while still meeting the reliability requirements of construction applications: IBT products withstand temperatures between -25°C and 40°C, resist a variety of harsh chemicals, and can tolerate four closed loops of either mechanical or chemical recycling.

Many of our enclosures are made from recyclable materials. We use polypropylene (PP) and polycarbonate across much of the range, and both are fully recyclable. Polypropylene can be recycled through multiple loops without losing its durability, suits both mechanical and chemical recycling processes, and its leachates are considered among the least hazardous when exposed to weathering. We are also certified under the DIN EN ISO 14001 environmental management system, which covers our efforts to reduce environmental impact from product design through to manufacturing.

The enclosures in our IBT range are made entirely from fully recyclable polypropylene (PP) copolymer. PP is widely accepted in recycling streams and can be reused in both mechanical and chemical processes, and it can go through multiple recycling loops without a significant drop in quality. We chose it because it is strong and durable enough for demanding construction environments while having a low environmental impact compared with other common plastics.

Electrical enclosures are suitable for switchboard arrangements, and our GTi ISO switchgear range is designed for them. A switchboard enclosure must protect the equipment it houses and protect users from direct and indirect electric shock. Our socket housing units are rated IP44, protecting against solid objects 1 mm in diameter and water splashes, while our empty housings are rated IP65, preventing dust intrusion and ingress from water jets. All GTi ISO insulated distribution boxes offer Class II IEC protection, and all our switchgear protects against impact to IK08.

You can divide a junction box or electrical enclosure into separate functional zones using partitions or divider panels, which keeps equipment on different voltages, circuits or current sources apart. To get it right, specify both the box and the partition walls correctly: size the enclosure and the dividers around the equipment and the room available, choose materials suited to the application, and check whether the dividers need a special capability such as pre-embossing for cable bushings. We supply a wide range of plastic partition walls and holders that divide enclosures lengthwise or crosswise.

Equipment using different nominal voltages can be kept separate inside a junction box, and doing so is vital for safe operation. Two things need specifying: the enclosure itself and the partition walls. Size them around the equipment and the space available, choose materials to suit indoor or outdoor use and the ingress protection required, and check whether the dividers need extras such as pre-embossing for cable bushings. Effective separation also avoids electromagnetic interference (EMI), which can cause signal disruption and hardware damage. In the UK, BS7671 Wiring Regulations require the presence of different voltages and where they can be isolated to be identified.

Partition walls can be added to an electrical enclosure to divide the space into separate functional zones or to give particular circuits additional insulation. They also add flexibility, as they can be moved or fully removed when an application is modified or upgraded. When specifying one, make sure it fits within the enclosure and is made of materials suited to the intended application, and check whether it needs a special function such as pre-embossing for cable bushings. We offer partition walls with holders for our AK, GEOS and TK series.

A switchboard enclosure has a dual function: as well as protecting the electrical equipment within, it must protect users from direct or indirect electric shock. It should therefore prevent the ingress of dust and water through a suitable ingress protection (IP) rating, offer suitable IK protection against impacts, and meet IEC Protection Class II standards. A modular setup that supports interconnectivity is also a common requirement, as it segregates the architecture and accommodates rapid expansion. We recommend our GTi ISO series of distribution boxes for low voltage switchgear, made from robust polycarbonate with interconnected housings that assemble quickly.

Yes. Plastic enclosures can be coloured as they are produced, during the injection moulding process, by mixing coloured pellets into the polymer melt. Our in-house manufacturing facilities in Schalksmühle, Germany, support custom-coloured plastic enclosures for high-volume purchases. We hold a large variety of pigment-based pellets and offer colours from the RAL, HKS and Pantone systems, whether the colour is needed for brand integrity or for safety, and we ensure colour consistency across the entire batch. We can also add multicoloured logos or graphics using digital, pad and screen printing, laser marking and hot embossing.

Yes. We offer a customisation service with digital and pad printing options to suit a wide range of applications. Thanks to our in-house printing capability, we can print images, logos and text in a wide variety of colours onto any of our enclosures, regardless of the material they are made from. Branding an enclosure this way supports brand identity, awareness and recall.

Our in-house enclosure assembly and customisation service is designed to shorten lead times for OEM and electrical installer customers. We fit DIN rails, terminals, cable glands and keypads, right through to fitting and wiring a controller, which means enclosures arrive as plug and play solutions. We take on single enclosures up to batch orders, including specialised enclosures for applications such as rail, and we can help with planning.

Electrical enclosures are available with transparent lids. We supply a range of enclosures and distribution boards with clear covers as well as opaque ones, so operators can see components, displays and labels at a glance without opening the lid, which helps prevent dust and water ingress. Our transparent-cover products come in a variety of ingress protection (IP) ratings and materials, and we can supply fully customised enclosures where a standard type does not fit.

We offer custom printing, including company logos, technical labels and safety instructions, applied directly to the lids of our enclosures. We use high-quality flatbed inkjet printers that print in full colour at up to 1,800 dots per inch, giving excellent durability and precision even on fine details and complex designs. The print stands up to outdoor exposure to UV rays, moisture and temperature changes without fading or peeling. We also offer custom assembly, supplying enclosures pre-fitted with specific components or modifications.

You can tell an enclosure is UL approved by the UL mark on its casing. This may be the standard UL mark, a variant such as C-UL US in Canada or UL-EU in the European Union, or an RU mark, used on components of UL listed products that cannot carry the full logo themselves. The relevant standards for enclosures are UL94, UL746C, UL50, UL50E and UL508. Products carrying UL markings that are bought from reputable manufacturers or distributors can fairly be assumed legitimate; if you have concerns, ask your supplier for details of the testing procedures. Note that UL508 is no longer tested for new products; IEC 60947 is the internationally recognised standard to look for in new products.

Yes. We provide certificates of conformity with all of our enclosures. We manufacture enclosures and components that meet the requirements of major European and North American standards, including VDE, EN, CSA and UL. Every enclosure is tested for compliance in our own UL- and EN-certified testing laboratory in Schalksmühle, Germany, which operates under the strict guidelines of the Client Test Data Program (CTDP). Our tests for EN, VDE and UL standards cover everything from IP ratings to safety requirements.

There is currently no standard or regulatory requirement for a sloped top on an enclosure in a food washdown environment. Sloped tops are widely used because they prevent liquids, debris and dust building up around the enclosure, and in many cases the solution will be a roof angled at between 8° and 20°. You should also select a suitable ingress protection (IP) rating: for high-pressure, high-temperature washdown, IP69K indicates the enclosure is dust-tight and able to withstand high-pressure and steam cleaning. Material choice also matters: aluminium, polycarbonate, polyethylene, polyurethane, duroplastic, thermoplastic elastomers and polyamide suit exposure to animal or vegetable fats, while polystyrene and ABS may not be suitable for food-grade applications.

UL 94 is the standard used to classify the burning behaviour of plastics, and it comprises two tests: horizontal burning (HB) and vertical burning (V). In both, a sample less than 3 mm thick is held above a 50 W, 20 mm high open flame. For HB, the sample is horizontal and exposed for 30 seconds, and qualifies as HB if it burns at a maximum speed of 76 mm per minute. For V, the sample is vertical and hit by the flame twice for 10 seconds: V0 if the flame is extinguished within 10 seconds, V1 if within 30 seconds with no burning drips, V2 if drips are present. The 5V test uses a 500 W, 125 mm flame applied five times for 5 seconds, giving 5VA if the material self-extinguishes with no dripping or burn holes, and 5VB if holes are observed.

The IQ symbol on the specification of some of our electrical enclosures stands for 'Industrial Quality'. We apply it to products designed to offer resilience, safety, ruggedness and longevity, which makes them suitable for harsh operating environments. IQ-marked enclosures withstand extremely low and high temperatures, are flame-, impact-, UV- and weather-resistant, can be used where harsh chemicals are present, and offer ingress protection ratings up to IP68.

Our WKE Rapid-Box range is designed for tunnel applications and meets key fire safety standards, in particular DIN 4102 part 12. The enclosures are precision engineered with temperature-resistant ceramic terminals and take uncut conductors of up to 50 mm² (Cu), with the junction made using a 2.5 mm² conductor or via a 3-pin or 5-pin CEE socket in the housing cover. The cable junctions and connection housings are certified according to EN 61439:2011, provide intrinsic fire resistance in the passage for 30 minutes and are rated to a minimum of IP66.

Yes. Our Lifeline WKE 2-6 range of fire-rated enclosures is designed with height-adjustable mounting rails that can be set in two different positions, providing space for installing single or double terminals as well as fuse holders. The terminal block sits on the mounting rail in the high position, while the low position is ideal for specific applications such as D0 (NEOZED) fuse mounting. The enclosures are attached by two external, pre-fitted lugs that rotate through 90 degrees, and the terminal block can be adapted on the base carrier in 45-degree steps by adjusting a central screw on a sliding bracket.

Look for glow wire testing carried out to the IEC 60695-2-11 series of specifications, which all Spelsberg enclosures undergo. The test applies a non-flaming heat source, such as a heated wire, to the specimen for 30 seconds, with tissue paper below it to check for dripping. To pass our glow wire testing, parts exposed to live components must not burn or glow when exposed to a wire heated to 960°C ±15°C, depending on the enclosure material. Any residual glow must extinguish within 30 seconds of the heat source being removed, and any falling parts must not ignite the tissue below.

We evaluate the durability of our plastic enclosures against excessive heat and fire using an indirect flame method known as the glow wire test, carried out in line with IEC standards. The sample is brought into contact with a hot filament for 30 seconds, with tissue paper positioned directly below it. Parts containing live components are exposed to 960°C ±15°C, cavity wall parts to 850°C ±15°C and all other components to 650°C ±15°C. The test is passed if the enclosure does not burn or glow, or if the glow extinguishes on its own within 30 seconds of the filament being removed, and if falling parts do not ignite the tissue paper.

Our Lifeline WKE 2-6 range combines intrinsic fire resistance with features designed to speed up installation. The boxes are made from high-performance polycarbonate that stays non-conductive in a fire, supporting systems that need to stay operational for 30, 60, 90 or even 120 minutes. The adjustable mounting rail can be set in two height positions for single or double terminals and fuse holders, with the lower position suiting D0 (NEOZED) fuses. The base carrier repositions in 45-degree steps using a single screw, the external fixing lugs are supplied pre-fitted and rotate through 90 degrees, and patented knock-out membranes give clean, quick cable entry.

Yes. We offer a wide range of certified NEMA 4X and IP66-rated enclosures for harsh conditions, and we can deliver samples to UK customers within 24 hours; where an off-the-shelf product does not fit, we can produce a fully customised enclosure. NEMA 4X, defined by the U.S. National Electrical Manufacturers Association, covers indoor and outdoor use needing protection against corrosion, dust, rain, dripping and light splashing of liquids, as well as external ice formation. It is equivalent to UL 50 Type 4X and comparable to the IP66 rating under BS EN 60529. Our GEOS series is one such range.

Yes, you can split an order across more than one delivery address. Our packing service lets you set a delivery address for each individual item in an order, which is useful if your business runs across several sites or the parts are going into different projects. We can also deliver different components of one product separately, pack into third-party cartons or containers, and supply special or custom-made crates.

We have offered phone-based technical support since 2015 through our teleservice, Spelsberg Pro-Active. Every enquiry is answered immediately by technically trained sales experts rather than order-takers, so you can get design and specification advice as well as place orders for standard or custom-made enclosures. Orders are processed and confirmed the same day, and you keep a single point of contact from order through to completion.

To identify the right enclosure for a project, work through four things in order. First, define the dimensions, both outer and inner, based on the room available where the unit will be installed and what it has to contain. Second, consider the environment, which determines the material, the level of protection needed against dust, water and mechanical stress, and any certificate or functional integrity level you require. Third, evaluate the number of distribution units and the dimensions of the cable cross sections you plan to use. Finally, decide whether you need a transparent lid for visibility, or a specific colour for branding or to help operators.

Enclosures for caravan and camping sites must meet DIN VDE 0100-708, or the equivalent IEC 60364-7-708 used in some countries. Both require a protection class higher than 0, a minimum splash protection rating of IPX4, IPX6 or a protective housing where equipment is cleaned at high pressure, at least IP4X protection against solid materials, and a minimum impact protection rating of IK07 to withstand reasonably foreseeable mechanical stress. Spelsberg's Abox, Abox Pro and GEOS enclosures are all suitable for outdoor caravan and camping sites.