In areas where appliances are exposed to water, such as bathrooms, electrical safety zones have been defined. They are of great importance when installing bathroom thermostats and other electrically powered equipment. It is therefore worth reading the definition of these areas and knowing what they mean in practice.
What are electrical protection zones?
Safety zones, also known as bathroom moisture zones, indicate areas where appliances with a certain degree of electrical protection can be installed so that they can be used safely. The photo at the top shows how the aforementioned bathroom safety zones are arranged.
It is possible to distinguish several important zones occurring in areas with increased moisture. These are shown in the graphic above and include:
- Zone 0 – the most dangerous area where equipment can come into direct contact with water. Therefore, an IP rating of x7 is required (the first number, specified with an “x”, is not very important in wet zones. The second value is primarily important). How to read each degree of protection is described in the section below. Returning to zone 0, it is worth mentioning that devices connected in such a place should have a constant power supply of up to 12 volts, that is, safe for humans even when fully flooded. This is how jets in whirlpool tubs or most lamps in swimming pools are constructed.
- Zone 1 – is located directly above where water collects, i.e. bathtubs and showers. It covers the space up to a height of 2.25 m, which will often be the entire height of the room. In this case, a protection level of IPx5 is required. Often in zone 1 you can find LED strips powered by 12 V DC. These are fully safe. However, transformers powering this type of lighting should be found only in zone 3.
- Zone 2 – includes the space around the water tanks. The width of the zone is about 60 cm. In this area, the equipment should have a minimum IPx4 safety rating.
- Zone 3 – that is, the remaining space in the room. In the figure, this will be the part of the bathroom covered by the white color. The risk of high humidity in this area is not high, so the IPx1 rating in private buildings is sufficient (although in public bathrooms it is IPx5). However, the most common devices are those marked IP44.
The use of such zones allows the safe installation of electrical equipment with specific moisture protection parameters. Unification of indications increases the safety of all users.
What does the IP rating of the device indicate?
Every electrical device has an enclosure. Its tightness helps protect live components from unwanted foreign bodies. The main task of such an enclosure is to protect users from touching wires and connectors with their bare hands, thereby avoiding electrocution.
However, the use of gaskets and well-fitted components allows for much better protection of electrical components, especially against the most dangerous ones: dust and water, which have the greatest impact on the failure rate of powered devices. Each enclosure has a specific degree of protection, consisting of two letters “IP” and at least two numbers. The first describes protection against dust and small foreign objects, while the second describes protection against water. The table below describes each value in detail.
| First digit | Type of protection | Second digit | Type of protection |
|---|---|---|---|
| 0 | Lack of protection | 0 | Lack of protection |
| 1 | Protection against bodies over 50 mm in size (accidental hand touch) | 1 | Protection against vertically falling water drops (due to condensation) |
| 2 | Protection against bodies over 12.5 mm in size (accidental finger touch) | 2 | Protection against water droplets falling on the housing at an angle of 15° from the normal position |
| 3 | Protection against bodies over 2.5 mm in size (accidental contact with a wire or screwdriver) | 3 | Protection against drops falling at an angle of 60° from the vertical |
| 4 | Protection against bodies over 1 mm in size (thin tool, thin wire) | 4 | Protection from drops falling at any angle, from all sides (rain) |
| 5 | Protection against the ingress of dust in amounts that do not interfere with the operation of the device | 5 | Protection against water jets from any direction |
| 6 | Total protection against dust ingress | 6 | Protection against strong water jets or wave flooding from any direction |
| X | – | 7 | Protection against flooding when submerged to such a depth that the bottom surface of the housing is 1 m below the water surface, and the upper surface is not less than 0.15 m for 30 minutes |
| X | – | 8 | Protection against flooding with continuous immersion and increased water pressure (1 m depth) |
| X | – | 9 | Protection against flooding by pressurized water jet |
In the case of a bathroom thermostat described with an IP44 rating, you can be sure that foreign bodies with a diameter of more than 1 mm will not get inside. At the same time, such an enclosure protects electrical components from water splashing in from all directions.
The most secure devices have an IP68 rating and are fully protected from dust and moisture. However, under normal conditions, there is no need to buy a thermostat with such a complex and advanced housing (which will also affect their price).
Is it safe to install a thermostat in the bathroom?
Installation of a typical thermostat in a bathroom is possible only in zone 3. Not only because of the use of an enclosure with a rating of at most IP44, but also because of the connection to the external network. Although it is theoretically possible to install a device marked IP21 (protection against objects over 12 mm and water falling vertically on the device), it is recommended to use IP44-rated models, typically designed for bathrooms and rooms with increased humidity. This is because it is worth remembering the water that settles on the tiles on the walls and runs down during hot baths.
It is also possible to use special seals that increase the safety class to IP44. They are used between the bathroom thermostat and the wall to protect the wires connected to the device.
It is also worth remembering that the bathroom thermostat has a built-in temperature sensor, so it must be in the same room as the heating system it controls.
Electric protection zones, and heating mats in the shower
It would seem that laying a heating mat is not possible in zone 0 or zone 1. These, however, cover the area from the floor up! This means that installations embedded in the adhesive under the tiles are not covered by them and do not belong to either zone.
However, this does not mean that any heating mat can be installed in the shower! Only models with the appropriate safety certificate can be laid in this type of place. It turns out that there are few products of this type. Among the heating systems offered by nVent RAYCHEM, only the QuickNet-160 heating mat is designed to heat the shower floor.
If you are not sure which mat to choose and where to mount the thermostat so that it works safely, write your question in the comments below. We will be happy to advise and give you a hint.
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