The enclosure protecting those panels isn’t a secondary element of the project: it’s the first line of defense against an environment that, over time, ends up taking a toll on any material that isn’t built to withstand it.
At Volthree, we regularly work with projects and installers facing this type of installation, and the question that comes up most often is always the same: what protection rating and what material do I actually need for the enclosure to hold up without giving problems?
Why a treatment plant is one of the most aggressive environments for an electrical enclosure
Chlorine and oxidizing agents
Chlorine and its derivatives, present in much of the water disinfection process, are highly corrosive to metals that lack adequate chemical resistance. Exposure is rarely occasional; it’s constant and cumulative, which means the effects show up gradually and are often noticed only once the deterioration is already visible.
Constant humidity and condensation
In a water treatment plant, ambient humidity rarely drops below high levels. On top of that, internal condensation builds up whenever there are temperature swings between the inside of the enclosure and the outside, a phenomenon that can affect both the enclosure material and the electrical components housed inside if it isn’t managed properly.
Salinity in coastal plants
When the installation is located near the coast, ambient salinity adds to the rest of the aggressive factors. The combination of chlorides and humidity is one of the most common causes of premature corrosion in metal enclosures that aren’t prepared for that level of demand.
What IP rating is recommended (and why it’s not always enough)
In water treatment plants, it’s standard practice to work with a minimum protection rating of IP65 or IP66, especially in process rooms, chemical dosing areas, or locations exposed to hose washdowns. In spots with a higher risk of pressurized water exposure, or where the installation is outdoors, it may be necessary to consider IP66 or higher.
That said, the IP rating only certifies sealing against solids and liquids: it says nothing about the material’s resistance to chemical corrosion. An IP66 enclosure made from an unsuitable material can maintain its seal and still deteriorate, inside or out, due to chlorine or salinity. Specifying by IP rating alone, without factoring in the material, is one of the most common mistakes in this type of project.
Why stainless steel is the standard choice in this sector
In environments with constant exposure to chlorine, humidity and, where applicable, salinity, stainless steel electrical enclosures have become the go-to solution over painted or coated steel enclosures. Stainless steel’s corrosion resistance doesn’t depend on a surface coating that can wear away over time; it’s a property of the material itself, which reduces the risk of failure due to finish degradation in installations where cleaning and chemical exposure are constant.
This doesn’t mean stainless steel is the automatic answer for every point in the plant: in less exposed areas, it may not be necessary. But in chemical dosing rooms, chlorine treatment areas, or coastal installations, it’s typically the option that avoids problems in the medium term.
Ventilation and climate control vs. total sealing: the real technical dilemma
One of the common challenges in designing electrical panels for water treatment plants is balancing two needs that, in principle, pull in opposite directions: maintaining a high level of sealing against the outside environment, and dissipating the heat generated by the electrical components housed inside the enclosure.
A fully sealed enclosure with no thermal management system can build up heat and encourage internal condensation, especially where there are temperature swings between day and night. The solution isn’t to sacrifice sealing, but to incorporate suitable climate control systems (filtered ventilation, heat exchangers or compact air conditioning units, depending on the case) that manage internal temperature without compromising the enclosure’s protection rating.
What to consider before specifying the enclosure
- The IP rating required based on the exact location within the plant (process room, outdoors, chemical dosing area)
- The level of exposure to chlorine, acids or other process chemical agents
- Whether there’s a risk of salinity due to proximity to the coast
- The need for internal thermal management without compromising sealing
- The ease of long-term cleaning and maintenance of the chosen material
Frequently asked questions about electrical enclosures in water treatment
What IP rating does an electrical enclosure need in a WWTP?
It depends on the exact location, but it’s standard to start with IP65 in process areas and consider IP66 in spots with pressure washdowns or outdoor exposure.
Is stainless steel mandatory in water treatment plants?
It’s not mandatory across the board, but in areas with chlorine, constant humidity or salinity, it’s the option that best prevents corrosion issues in the medium and long term.
How is internal condensation prevented in these enclosures?
By incorporating suitable climate control systems, filtered ventilation, anti-condensation heaters or air conditioning units that manage internal temperature without giving up the enclosure’s sealing.
Does a high IP rating replace the need for stainless steel?
No. The IP rating certifies sealing against solids and liquids, but it doesn’t protect against chemical corrosion. Both factors (IP rating and material) need to be specified independently.
At Volthree, we distribute stainless steel enclosures designed to adapt to the real demands of every point in the installation, including water treatment plants. If you need help specifying the right enclosure for your project, get in touch with our team.