The constraint set, in order
| Requirement | Design consequence |
|---|---|
| Weather protection | Continuous gasket groove, sloping top, no horizontal seam on the weather side |
| Passive cooling | Louvred inlet low, filtered outlet high, generous open area with insect mesh |
| Wind and pole load | Mounting bracket and local stiffening, not overall sheet thickness |
| Security | Lock and hinge reinforcement; the door is the weak point, not the panel |
| Earthing and bonding | Masked studs and lands; galvanised or bare stainless surfaces |
| Cable entry | Gland plate or sealed entry, bedded against bare metal, with a drip loop |
| Fibre management | Bend radius respected inside the cabinet; no sharp edge anywhere a cable touches |
Sealing is a path, not a surface
A gasket has to run continuously around the aperture with no interruption. Every weld that crosses that path, every corner that changes direction across a hinge cut-out, and every flange that is not flat breaks the seal. The usual answer is to form the groove as one continuous feature in the moving part and move any welded joint behind the seal land, where a bead does not matter.
The cable entry is the second half of the same problem. It has to let a cable through and keep water out, so the gland seats against bare metal with a properly formed face and the cabinet is designed with somewhere for water to go if it does get in.
Material and finish for an unattended outdoor part
Galvanised steel with a textured powder coat handles most street-level installations: the zinc protects cut edges and the coat protects the appearance. Coastal and chemically aggressive sites push the specification to 304 or 316 stainless, where the premium buys service life rather than appearance.
Whatever the substrate, the interior of a steel cabinet is normally coated too, because a plant-room-free outdoor cabinet rusts from the inside as well as the outside. That means internal masking and internal access for the coating — which is a design decision about door size and removeable panels.
- Keep the assembly order in mind: anything welded inside is welded before the box closes.
- Give the filter on the outlet a replacement path — a clogged filter that cannot be changed degrades the thermal design permanently.
- Reinforce around the lock, not just the hinge; forced entry usually starts at the lock.
- Allow for lifting and pole-mounting during installation, which loads the cabinet in ways its service life never will.