Control Panel Enclosure Materials, Gland Plates and Protection Levels

Two control panels can look identical and behave completely differently, because the differences are in the material, the wall thickness, the way the cables enter and the way the earth path runs. Those four decisions are made very early and are very hard to change later, which is why they are worth more attention than the colour of the door.

The Four Decisions That Are Hard to Change

Steel, Stainless and the Environment

• Coated steel for indoor and protected outdoor panels, the economical default.
• Stainless where corrosion, washdown or hygiene requires it, and where a longer life justifies the cost.
• Aluminium where weight matters, such as wall or machine-mounted panels.
• The choice follows the service environment, including humidity, chemicals, salt and cleaning regime.
• If the site is not known, say so; we will design for a stated class rather than guess one.

Thickness, Stiffness and What They Solve

• Thickness and stiffening solve the same problem; use forming before adding material.
• A large door needs rigidity, or it sags, seals badly and rattles.
• A flat back plate needs stiffness, or it distorts when components are tightened onto it.
• Very thin material saves cost on small boxes and creates problems on large ones.
• Consider the weight of the mounted equipment, not only the panel's own size.

Finish, Corrosion Class and Appearance

• Choose a coating system to suit the environment; a decorative finish is not a corrosion system.
• Specify the colour and gloss where appearance or solar gain matters.
• Mask bonding faces and mating faces before coating, so the finish does not break a path.
• Consider touch-up in service; a finish that is easy to repair is worth having.
• Keep the internal finish consistent, because service lighting can make a light interior much easier to work in.

Gland Plates, Entries and the Boundary

• Provide a removable gland plate at the bottom, and where required at the top.
• Size the plate for the cables plus spare, and keep spares blanked.
• Keep the drilling away from the main panel, so that swarf cannot reach live components.
• Allow the plate to be removed and drilled on the bench, which is much easier than drilling in place.
• Provide strain relief at the entry, and keep the cable weight off the terminations.
• Where the panel sits in a washdown or dusty area, match the entry protection to the panel's own class.

Protection Levels and How They Are Kept

• Decide the IP requirement with the environment and the cleaning regime in mind.
• Remember that a gland plate, a vent or a fan all become part of the enclosure's protection; the class is what the finished assembly achieves.
• Keep gasket channels and sealing surfaces free of coating and damage.
• Provide louvres or vents only where the thermal design needs them, and protect them.
• Check the class after finishing, not only at the steel stage.

Earthing and Bonding Points

• Provide a labelled main earth terminal sized for the installation.
• Bond doors, covers and gland plates with dedicated conductors.
• Mask bonding faces before coating, and record the points on the drawing.
• Keep bonding accessible for testing.
• Use hardware suited to the environment, particularly for outdoor and coastal sites.

Back Plates, Rails and Internal Accessories

• Provide a mounting plate or rails with the fixing pattern the layout requires, and ensure it is stiff enough.
• Provide cable ducts and trunking provisions where the design calls for them.
• Leave space for future components, because panels grow.
• Provide document pockets or a holder position, so that drawings travel with the panel.
• Keep service access to devices clear of the cable routes.

Thermal Considerations in the Panel

• Provide ventilation or cooling provisions where the heat load requires, and size them for the worst ambient.
• Keep filters accessible and document the change interval.
• Place the hottest devices where the coolest air arrives.
• Remember that a sealed panel with no cooling relies on its surface, which is limited.

Checks on the Build

How We Approach Control Panel Enclosures

• We fabricate bodies, doors, gland plates, mounting plates, internal barriers, brackets and ventilation parts in steel, stainless and aluminium.
• We work to the layout and component drawings you supply, and we keep the mounting faces flat and the entries where the arrangement requires them.
• We will tell you when a requested protection class, a requested ventilation arrangement and a requested internal layout cannot all be met at once.
• We do not assemble the electrical components, we do not carry out the electrical design or testing, and we do not certify the panel to any standard.
• Every quotation states which operations are completed in our plant.

Send the environment, the layout and the entry requirements, and the panel can be built with the material, the entries and the earth path it actually needs.

Frequently Asked Questions