Re-take - Useful Information for 2394 :

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Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

Appendix 5

Classification of external influences P/400


defined as .
P/28 . External influence . Any influence external to an electrical installation which affects the design and safe operation of that installation.

These external influences are shown by the use of a code which has two capital letters and a number

The first letter shows the category of external influence.

The second letter shows what the external influence relates to and the number indicates the level of the external influence.
The first letter indicates which category the external influence falls under .

A . = Environment - ( wet . dry . vibration )
B . = Utilisation :
• How is the building being used .
• What is the capability of the persons using the building .
• Are they ordinary persons or persons are they handicapped .
C . = Construction of buildings . What is the building constructed from : Non-combustible . Combustible .

The second letter indicates what the external influence could be .
refer to appendix 5 and look in environment section ( category A )

example : if the second letter was K it would refer to; presence of flora ( and/or mould growth )
The last digit is a number and indicates the level of protection which the external influence is likely to be .

External influence given a code of ( AD1)
- Letter (A) relates to the environment .
- Letter (D) relates to water ... AD presence of water .
- Final digit (1) tells you that the problem likely to be caused by water is negligible . ( AD1)

Example: external influence given a code of (AD1)
you can see the letter (A) relates to the environment .

you can see the letter (D) relates to water .

first digit (1) tell you that the problem likely to be caused by water is negligible . (AD1)

you need to look further into Appendix 5 . When you find (AD1) you can see that it relates to areas where weather protection is not required and that the (IP rating ) for the equipment is ( IPX0) As the external influence relates to water nothing is specified for dust (X) and the level of protection against water is (0) which means no protection required .

At the other end of the scale , you can see that (AD8) is where the equipment is likely to be totally submersed, ( such as in a swimming pool )

The ( IP rating ) given as protection is (IPX8) shows that nothing is specified for dust and 8 shows that it must be protection against the effects of continuous immersion in water .

THE INDEX OF PROTECTION CODES IS USED THROUGHOUT BS-7671:2008:2011:2015: to identify the minimum level of protection permissible .

P/405 : A Environment (cont.)
Code External influences : Characteristics required for selection and erection of equipment : Reference for information only .

AD Presence of water
AD1 Negligible
IPX0 Outdoor and non-weather protected locations, with low and high temperatures .

AD2 Free-falling drops
1PX1 or IPX2 Location in which water vapour occasionally condenses as drops or where stream may occasionally be present .

AD3 Sprays
IPX3 Location in which sprayed water forms a continuous film on floor and/or walls .

AD4 Splashes
IPX4 Locations where equipment may be subjected to splashed water; this applies, for example, to certain external luminaires, construction site equipment

AD5 Jets
IPX5 Locations where hose water is used regularly ( yards, car-washing bays )

AD6 Waves
IPX6 Seashore locations such as piers, beaches, quays, etc.

AD7 Immersion
IPX7 Locations which may be flooded and/or where water may be at maximum 150mm above the highest point of equipment, the lowest part of equipment being not more than 1m below the water surface .

AD8 Submersion
IPX8 Locations such as swimming pools where electrical equipment is permanently and totally covered with water under a pressure greater than 0.1 bar .

External influences :


Regulation 301.1. and more particularly Chapter 32 and Appendix 5 of BS-7671: deal with external influences which needs to be assessed by the designer and taken into account in the subsequent installation design and construction .

(ii) The external influences to which it is to be Exposed ( Chapter 32 )

 

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Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

Protection by barriers or enclosures

416.2.
The term enclosure is readily understood as being a construction which prevents live parts being touched. Barriers are, because of the common English usage, sometimes confused with Obstacles .

A barrier in the sense of the regulations is similar to an enclosure in that it is a part providing a defined degree of protection against contact with live parts, with the difference that the protection is only provided in the usual direction of access.

An enclosure provides protection in any direction .
A barrier may not have protection against contact from above.

The basic-requirement for IP2X is that the live part should be inaccessible to a finger .
The basic-requirement of IP4X is that it should be inaccessible to a wire .

As the regulations state. The higher degree of protection is required on Top of an Enclosure to prevent small items falling through .

In general, barrier(s) or enclosure(s) should only be able to be removed or opened by the use of a Key or Tool .

IP ? X
First characteristic :
Numeral

Against ingress of solid foreign objects 2 > 12.5mm diameter
Against access to hazardous parts with non-protected finger

Against ingress of solid foreign objects 4 > 1.0mm diameter
Against access to hazardous parts with non-protected wire

 

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Avoiding damage to Cables due to condensation or ingress of water .

like any other part of the wiring system, cables are subject to Regulation 522.3.1. which requires that : :icon_bs:
“ A wiring system shall be selected and erected so that no damage is caused by condensation or the ingress of water during installation ” use or maintenance

Regulation 522.3.1 ... The completed wiring system shall comply with the IP degree of protection relevant to the particular location.

Note: Special considerations apply to wiring system liable to frequent splashing, immersion or submersion .

 

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RCD Protected Switch socket Outlet

( What’s in a name ! a big difference ) ... Active or Passive RCDs :30:

Active control circuits Incorporate a ‘Re-set’ mechanism and are mains failure sensitive, i.e. they will function under all the normal conditions expected of an RCD, but will also trip in the event of a power cut or a sudden, dramatic reduction in mains voltage.

Passive control circuits Incorporate a ‘Stay-set’ mechanism and is mains failure proof, i.e. it will function under all the normal conditions expected of an RCD and will not trip in the event of a power cut.

 

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A list of (( External influences )) and their characteristics have been included as an appendix ( i.e. Appendix 5 ) to BS-7671:2008:2011:2015: :icon_bs:
What the regulations are stating. The following notes concerning external influences are offered as Guidance.

132.5. Environment conditions
132.5.1. The design of the electrical installation shall take into account the environmental conditions to which it will be subjected .

re-cap . ↑
[ Equipment likely to be exposed to weather, corrosive atmospheres or other adverse conditions shall be so constructed or protected as may be necessary to prevent danger arising from such exposure. ]

512.2. External influences Etc.
512.2.2. Equipment shall be of a design appropriate to the situation in which it is to be used or it’s mode of installation shall take account of the conditions likely to be encountered .

530.3. requirements from the regulations . General; External Influences
Equipment shall be selected and installed to provide for the safety and proper functioning for the intended use of the installation. Equipment installed shall be appropriate to the (( external influences foreseen ))

 

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Chapter 52.
Selection and Erection of Wiring Systems .

526. Electrical Connections’ . :icon_bs:
526.6. There shall be no appreciable mechanical strain on the connections of conductors.
526.7. Where a connection is made in an enclosure the ((enclosure shall)) provide adequate mechanical protection and protection against relevant External influences

 

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long way for a short-cut.

External influences are all over the regulations. (know your IP codes )

learning curve only . 702.414.4. Requirements for SELV and PELV circuits.

702.414.4.5. Where SELV is used, whatever the nominal voltage, basic protection shall be provided by :
416.1 - Basic insulation ; or
Barriers or enclosures and affording a degree of protection of at least IPXXB or IP2X. Complying with 416.2. :icon_bs:

 

[amberleaf]

Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

Learning curve only. :icon_bs:

702.55.4. Special requirements for the installation of electrical equipment . etc refer ........................................

Fixed equipment designed for use in swimming pools and other basins ( e.g. filtration system, jet steam pumps ) and supplied at low-voltage is permitted in zone 1 , subject to all the following requirements being met:

- The equipment shall be located inside an insulating enclosure providing at least Class II or equivalent insulation and providing protection against mechanical impact of medium severity ( AG2)

P /406 ( Code > AG - External influences : Mechanical stress impact ) & ( External influences : AG2 - Medium severity )

 

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Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

Leaning cure only . ( Where do I use the IP Codes )

P/216 . Fig - 702.1. Zone dimensions for swimming pools and paddling pools . :icon_bs:

Equipment selected for Zone 2 would need to be manufactured to an IP rating of IPX2 (drip proof) for indoor locations, IPX4 (splashproof) for outdoor locations or, where water jets are likely, IPX5 (jet proof). Again, the manufacturers’ guidance on installation and suitability should be followed.

:book: Zone 0 – the interior of the swimming pool basin
Zone 1 – the area surrounding the edge of the pool for a distance of 2.0 m and a height of 2.5 m
Zone 2 – the area surrounding Zone 1 for a further distance of 1.5 m and a height of 2.5 m

NOTE it is important to remember that because the swimming pool is considered a special installation or location, due to the wet conditions, basic protection for any SELV circuit must have basic insulation or the conductors must be behind barriers and enclosures to at least IP2X.

Index of protection IP codes for general guidance.
Zone 0 :- Minimum degree of protection :- IPX8.
Zone 1 :- IPX4 or IPX5 for water jets likely to occur for cleaning purposes.
Zone 2 :- IPX2 for indoor locations, IPX4 for outdoor locations and IPX5 or water jets likely to occur for cleaning purposes .

 

[amberleaf]

Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

P/216 . Fig - 702.1. Zone dimensions for swimming pools and paddling pools .

The power or right to decide or act according to one's own judgment ........... :aureola:


For zone 0, the protective measure against electric shock would need to be provided by SELV at a nominal voltage not exceeding 12V.

Equipment selected for the interior of the basin (Zone 0) would need to be manufactured to an IP code of IPX8.

For Zone 1, the protective measure against electric shock would need to be provided by SELV at a nominal voltage not exceeding 50V.

Equipment selected for Zone 1 would need to be manufactured to an IP code of IPX4 (splashproof) or where water jets are likely, IPX5 (jet proof)

BS:7671 allows a conventional BS 1363 socket outlet, providing it is non-metallic, to be installed at least 1.25 m from the edge of the pool and at least 0.3 m from the floor. The protective measure against electric shock for this socket outlet circuit would generally be automatic disconnection of supply with the additional protection of a 30mA RCD.

Lighting circuits in Zone 1 do not necessarily need the protective measure of SELV if they are installed on a wall within the zone’s dimensions providing that:
• The circuit protected by automatic disconnection of the supply and additional protection is provided by a 30mA RCD.
• The height from the floor to the luminaire is at least 2 m.
• The luminaire shall have an enclosure providing Class II or equivalent insulation.
• Protected against impact of medium severity (AG2).
• Automatic disconnection of the supply (which includes earthing and bonding) used in Zone 2 would require the additional protection of a 30mA RCD.

Supplementary equipotential bonding shall be provided, connecting all extraneous conductive parts and exposed conductive parts in Zones 0, 1 and 2 together. Where a metal grid is installed in a solid floor, it should be connected to the local supplementary bonding.

Wiring systems, surface wiring or otherwise, should preferably not employ metallic conduit, trunking or exposed metallic sheath.

Underwater lighting located behind portholes, and serviced from behind, must comply with the appropriate part of BS-EN-60598 and be installed in such a way that no intentional (or unintentional) conductive connection between any exposed conductive part of the underwater luminaires and any conductive parts of the portholes can occur

P/306. BS-EN-60598 Luminaires . :book: :icon_bs:

 

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BS-7671:2008:2011:2015:

Special installations or locations because of the increased risk of shock arising from the fact that a person’s body resistance is significantly reduced when wet and only partially clothed and by good contact with earth.

Locations require a higher degree of protection for equipment, which is likely to be subject to water splashes or sprays.

Special requirements not only apply to the swimming pool but also to the surrounding area.

 

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Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

Equipment selected for the interior of the basin (Zone 0) would need to be manufactured to an IP rating of IPX8, which means that the underwater lighting equipment would be able to withstand any water ingress when totally submerged with water under a pressure greater than 0.1 bar. The manufacturers’ guidance on installation and suitability should be followed, and you should also confirm that the underwater luminaire complies with BS-EN-60598-2-18.

P/306. BS-EN-60598-2-18:1994 + A1:2012. Luminaires.
Particular requirements, Luminaires for swimming pools and similar applications . 702.55.2. 702.55.3. :icon_bs:

 

[amberleaf]

Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

There are two sets of code’s to relate to (IP) wise.

1) International Protection (IP) Code’s ...... ◄ :uhoh2:
2) Ingress Protection. (British) BS-7671: ◄ P/405. IP codes. :icon_bs:


416.2 Barriers or enclosures
Note: Barriers or enclosures are intended to prevent contact with live-parts.

A letter (B) is sometimes added after (XX) IPXXB the XX means that the first and second numbers are NOT specified . (B) Means finger protection is provided against any hazard in the Enclosure.

Electrical equipment (Enclosures) are specified in the form (IPXX?) As appropriate.
“ first ” and/or “second ” X is replaced by a number . IP2X. IP??2X )

416.2.1. Live parts shall be inside enclosures or behind barriers providing at least the degree of protection IPXXB or IP2X . Refer. Etc
416.2.4. (iii)
where an intermediate barrier providing a degree of protection of at least IPXXB or IP2X . prevents contact with live-parts, by the use of a key or tool to remove the intermediate barrier

 

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Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

Notes IP Codes .
First :
- Degree of protection is stated in form ((IPXX))
- Protection against contact or ingress of water respectively is specified by replacing first or second (X) by digit number tabled e.g. (IP2X) defines an (enclosure) giving protection against finger contact but without any specific protection against Ingress of water or Liquid .

This information should be used for general guidance only. Refer to BS-EN-60529. for full information.
Where the first or second numeral is not required to be specified, it is replaced by the letter (X)

There are two sets of code’s to relate to (IP) wise.

1) International Protection (IP) Code’s ...... ◄
2) Ingress Protection. (British) BS-7671: ◄ P/405. IP codes. :icon_bs:

 

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What new to BS-7671:2015

Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

INTERNATIONAL PROTECTION code. 412.2.2.3. :uhoh2: :book:

BS-7671:2015.
P/41. - Abbreviations used in the Standard. (IP) International Protection Code . ◄◄◄ :30:

P/66. - 412.2.2.3. Where a lid or door in an insulating enclosure can be opened without the use of a tool or key, all conductive-parts which are accessible if the lid or door is open shall be behind an insulating barrier (providing a degree of protection not less than (IPXXB or IP2X) preventing persons from coming unintentionally into contact with those conductive-parts . This insulating barrier shall be removable only by the use of a tool or key.

 

[amberleaf]

Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

P/234 - Section 709
Marinas and Similar Locations. :svengo:

IP characteristic numerals .
First -
a) Protection of persons against access to hazardous parts inside enclosure(s)
b) Protection of equipment against ingress of solid foreign objects.

Second - Protection of equipment against ingress of water.
No. Degree of protection
First - 0
(a) Not protected
(b) Not protected
Second - Not protected

First - 1
(a) Protection against access to hazardous parts with the back of the hand.,
(b) Protection against foreign solid objects of 50 mm diameter and greater.
Second - Protection against vertically falling water drops.

First - 2
(a) Protection against access to hazardous parts with finger
(b) Protection against solid foreign objects of 12.5 mm diameter and greater.
Second - Protection against vertically falling water drops when enclosure tilted up to 15° vertically falling water drops shall have no harmful effects when the enclosure is tilted at any angle up to 15° from the vertical.

First - 3
(a) Protection against contact by tools, wires or such like more than 2.5 mm thick.
(b) Protection against solid foreign objects of 2.5 mm diameter and greater.
Second - Protection against water spraying at an angle up to 60° on either side of the vertical.

First - 4
(a) As 3 above but against contact with a wire or strips more than 1.0 mm thick.
(b) Protection against solid foreign objects of 1.0 mm diameter and greater.
Second - Protection against water splashing from any direction.

First - 5
(a) As 4 above
(b) Dust-protected (dust may enter but not in amount sufficient to interfere with satisfactory operation or impair safety)
Second - Protection against water jets from any direction.

First - 6
(a) As 4 above.
(b) Dust-tight (no ingress of dust)
Second - Protection against powerful water jets from any direction.

First - No code.
Second - 7
Protection against the effects of temporary immersion in water. ingress of water in quantities causing harmful effects is not possible when enclosure is temporarily immersed in water under standardized conditions.

First - No code.
Second - 8
Protection against the effects of continuous immersion in water under conditions agreed with a (manufacture)

 

[amberleaf]

Only be treated as an aide-mémoire to the Regulations and Electricians should always consult BS-7671:2015: to satisfy compliance.

P/234 - Section 709
Marinas and Similar Locations.

Risks at Marinas.

Degrees of protection provided by enclosures for electrical equipment against external mechanical impacts (IK code)
Code letters IK
(international mechanical protection) :30:

Characteristic group numeral
(00 to 10) ... example. IK/05

Each Characteristic group numeral represents an impact energy value as Shown below.
IK Code: IK00, IK01, IK02, IK03, IK04, IK05, IK06, IK07, IK08, IK09, IK10.

Impact energy
IK00 - No protection specified
IK01 - 0.15.
IK02 - 0.2.
IK03 - 0.35.
IK04 - 0.5.
IK05 - 0.7.
IK06 - 1.
IK07 - 2.
IK08 - 5.
IK09 - 10.
IK10 - 20.

Where higher impact energy is required, the value of 50 joules is recommended.

 

[Richard Burns]

Posted by request
Re-cap prior to the next edition:
Circuits Requiring Additional Protection (30mA RCD)

• Location: Sockets in dwellings up to 20A
Regulation No. 411.3.3.
Notes:
All sockets up to 20A rating must be 30mA RCD protected unless labelled for a particular item of equipment. The provision for omission of RCD protection where there is a Risk Assessment does NOT apply to dwellings.

• Location: Sockets in commercial premises
Regulation No. 411.3.3.
Notes:
All sockets up to 20A rating must be 30mA RCD protected unless labelled for a particular item of equipment. Or if there is a written risk assessment to say RCD protection is not required.

• Location: Mobile equipment outdoors with a rating of up to 32A
Regulation No. 411.3.3.
Notes:
Includes 3 phase supplies. No exceptions.

• Location: All low voltage circuits in a bathroom
Regulation No. 701.411.3.3. 701.415.2.
Notes: (None)

• Location: Circuits passing through bathrooms Zones 1 and/or 2
Regulation No. 701.411.3.3.
Notes:
Only applies to Zones 1 and 2, not to cables outside the Zones.

• Location: Cables without mechanical protection at a depth of less than 50mm in a wall
Regulation No. 522.6.202. 522.6.204
Notes:
Cables should be in Safe Zones and 30mA RCD protected.

• Location: Cables in walls with internal metal construction unless protected
Regulation No. 522.6.203. 522.6.204
Notes: Unprotected cables such as twin and earth in metal studwork walls.

• Location: Swimming pools
Regulation No. 702.410.3.4.2. 702.419.3.4.3. 702.53 702.55.1
Notes: Supplies to equipment in the Zones.

• Location: Saunas
Regulation No. 703.411.3.3.
Notes: All circuits in the sauna.

• Location: Construction sites
Regulation No. 704.410.3.10
Notes: 230/400V Sockets up to 32A.

• Location: Agricultural and Horticultural Premises
Regulation No. 705.411.1.
Notes: Sockets up to 32A.

• Location: Caravan and camping sites
Regulation No. 708.553.1.13.
Notes: All socket outlets. Each socket outlet to have individual RCD.

• Location: Caravans
Regulation No. 721.411.
Notes: All circuits and must interrupt all live conductors.

• Location: Marinas
Regulation No. 709.531.2.
Notes: Socket outlet. Device must disconnect all poles including the neutral. Sockets to be individually protected by an RCD.

• Location: Medical locations
Regulation No. 710.531.2.4. 710.411.4
Notes: Socket outlets and all circuits up to 63A in Group 1 locations.

• Location: Exhibitions, shows and stands
Regulation No. 711.411.3.3.
Notes: All socket outlets. All circuits other than those supplying emergency lighting.

• Location: Solar Photovoltaic (PV) power supplies
Regulation No. 712.411.3.2.1.2.
Notes: May be required for supply cable and RCD needs Type B.

• Location: Outdoor lighting installations
Regulation No. 714.411.3.3.
Notes: Lighting in telephone kiosks, bus shelters, advertising panels and town plans.

• Location: Mobile or transportable units
Regulation No. 717.515.1
Notes: LV circuits supplying equipment outside the unit.

• Location: Electric vehicle charging installations
Regulation No. 722.531.2.101.
Notes: Every charging point to have individual RCD that disconnects all live conductors.

• Location: Temporary installations for structures, amusement devices, fairgrounds etc
Regulation No. 740.415.1.
Notes: All lighting circuits, sockets up to 32A and mobile equipment up to 32A.

• Location: Floor and ceiling heating systems
Regulation No. 753.415.1.
Notes: Circuit supplying heating system.