Bathroom Zones
Bathrooms are considered to be a ‘special location’ for electrical installations because they have an increased risk of electric shock for the users, due to the proximity of water. Electrical contractors make bathroom installations safe with careful adherence to wiring and building regulations along with using correctly rated fittings.
In the UK, all fixed electrical installations in dwellings must legally comply with BS7671 the ‘Requirements for Electrical Installations’. This Standard gives specific guidance on the design, installation, testing, verification and certification of such installations. Section 601, particularly covers ‘Locations containing a bath or shower’.
Section 601, divides a bathroom into zones which take into account windows, doors, walls ceilings and partitions and is based on a perceived level of risk zone. Each zone has specific requirements regarding the electrical equipment that can be used in that zone.
Zone 0: the interior of the bathtub or shower basin.
Zone 1: the area around the bathtub or shower basin up to a height of 2.25m above the floor and at a radius of 1.2m from the water outlet.
Zone 2: is limited by the vertical planes external to zone 1 and parallel vertical plane (s) 0.60m external to zone 1.
Zone 3: is limited to the vertical plane(s) external to zone 2 and the parallel vertical plane(s) 2.40m external to zone 2.
Electrical equipment used in bathrooms must not be adversely influenced by environmental factors. These can include condensation, humidity, steam, drops of water or sprays from showers. There are a number of different indicators relating to electrical products that identify the products safety and suitability for bathroom use.
Bathroom electrical equipment must carry an appropriate Ingress Protection (IP) rating for its location. The Wiring Regulations make specific mention of Ingress Protection ratings:
• Zone 0 requires equipment to carry a minimum IP rating of IPX7 – that equipment is protected against the effects of immersion
• Zones 1 and 2 equipment should carry a minimum IP rating of IPX4 (protection against splashing water) or IPX5 if water jets are likely to be used for cleaning.
• In Zone 3 while there is no designated IP requirement for equipment in this zone, again an IP rating of IPX5 is required if the area is cleaned with water jets.
IP Explanation and Ratings
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EN 60529 outlines an international classification system for the sealing effectiveness of enclosures of electrical equipment against the intrusion into the equipment of foreign bodies (i.e. tools, dust, fingers) and moisture. This classification system utilizes the letters "IP" ("Ingress Protection") followed by two or three digits. (A third digit is sometimes used. An "x" is used for one of the digits if there is only one class of protection; i.e. IPX4 which addresses moisture resistance only.)
Degrees of Protection - First Digit
The first digit of the IP code indicates the degree that persons are protected against contact with moving parts (other than smooth rotating shafts, etc.) and the degree that equipment is protected against solid foreign bodies intruding into an enclosure.
| 0 |
No special protection |
| 1 |
Protection from a large part of the body such as a hand (but no protection from deliberate access); from solid objects greater than 50mm in diameter. |
| 2 |
Protection against fingers or other object not greater than 80mm in length and 12mm in diameter. |
| 3 |
Protection from entry by tools, wires, etc., with a diameter of thickness greater than 1.0mm. |
| 4 |
Protection from entry by solid objects with a diameter or thickness greater than 1.0mm |
| 5 |
Protection from the amount of dust that would interfere with the operation of the equipment. |
| 6 |
Dust tight. |
Degrees of Protection - Second Digit
The second digit indicates the degree of protection of the equipment inside the enclosure against the harmful entry of various forms of moisture (e.g. dripping, spraying, submersion, etc.)
| 0 |
No special protection |
| 1 |
Protection from dripping water. |
| 2 |
Protection from vertically dripping water. |
| 3 |
Protection from sprayed water. |
| 4 |
Protection from splashed water. |
| 5 |
Protection from water projected from a nozzle |
| 6 |
Protection against heavy seas, or powerful jets of water. |
| 7 |
Protection against immersion. |
| 8 |
Protection against complete, continuous submersion in water. |
Submersion depth and time must be specified by the end-user. The requirement must be more onerous than IP67
The IP Code Symbols
The chart at the right illustrates the use of special symbols in the IP classification system. In the "1st digit" column, not the grid-like symbols net to numbers 5 and 6. In the "2nd digit" column numbers 3-8 are symbolised by teardrop shaped symbols, sometimes enclosed in a box or a triangle, sometimes unenclosed (#7-8). These symbols can be placed on equipment to illustrate the IP protection provided.
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