ETSI TR 101 562-1 V1.3.1 (2012-02)

Technical Report
PowerLine Telecommunications (PLT);
MIMO PLT;
Part 1: Measurement Methods of MIMO PLT

2 ETSI TR 101 562-1 V1.3.1 (2012-02)

Reference
RTR/PLT-00036
Keywords
MIMO, powerline
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3 ETSI TR 101 562-1 V1.3.1 (2012-02)
Contents
Intellectual Property Rights . 5
Foreword . 5
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Symbols and abbreviations . 7
3.1 Symbols . 7
3.2 Abbreviations . 7
3.2.1 Abbreviations Used for Feeding Styles . 8
4 Major Project Phases . 9
5 Motivation . 9
6 Worldwide Evaluation of the Presence of the Protective Earth (PE) Wire in Residential Dwellings . 10
6.1 Grounding Systems . 10
6.1.1 TN Networks . 11
6.1.1.1 TN−S . 12
6.1.1.2 TN−C . 12
6.1.1.3 TN−C−S . 12
6.1.2 TT Network . 13
6.1.3 IT Network. 14
6.1.4 Regulations of Earthing Networks . 14
6.2 Wall Socket Types Used in Various Countries . 15
6.2.1 3 Pin Type Sockets . 15
6.2.2 Countries in which PE Grounding is Not in Use . 17
6.2.3 Countries where PE Type Sockets are Exclusively Used . 18
6.3 Regulation Approach to Estimate Presence of Protective Earth . 18
6.3.1 European Countries. 18
6.3.2 United States . 20
6.3.3 Canada . 21
6.3.4 More Detailed Information about a few Countries . 21
6.3.4.1 Presence of PE Wire in Belgium . 21
6.3.4.2 Presence of PE Wire in France . 22
6.3.4.2.1 Historical PE relative standards . 22
6.3.4.2.2 Statistical Data . 23
6.3.4.3 Presence of PE Wire in Switzerland. 25
6.3.4.4 Presence of PE Wire in the US . 25
6.3.4.5 Presence of PE Wire in Spain . 27
6.3.4.5.1 Electrical Regulations Data for Spain . 27
6.3.4.5.2 Spanish Housing Data . 27
6.3.4.5.3 New Housing built in Spain Since 1974 . 28
6.3.4.5.4 Data on Housing Renovations . 29
6.3.4.5.5 Summary Figures: Housing, Renewals and PE Installations . 30
6.3.4.5.6 Variation in the Rate of PE Installations in Renovated Housing . 30
6.3.4.5.7 Conclusion: Electrical Installation Practices in Spain . 30
6.4 Secondary Information for Estimating the Presence of PE . 30
6.5 Survey of Worldwide Electrical Standardization Committees and Engineering Clubs . 30
6.5.1 Information Collection Methodology . 30
6.6 Worldwide Earthing Situation by Country - an Estimation Table . 35
7 Measurement Description of Joint Equipment from Channel, Noise and EMI Measurements . 50
7.1 MIMO PLT Universal Coupler . 51
ETSI
4 ETSI TR 101 562-1 V1.3.1 (2012-02)
7.1.1 Safety Note . 51
7.1.2 Objectives of the MIMO PLT (STF 410) Design . 52
7.1.3 Technical Data of Couplers . 52
7.1.3.1 Impedance Conditions . 52
7.1.3.2 Insertion Loss . 53
7.1.4 Operation . 53
7.1.4.1 SISO Transmit and SISO Receive (Example P-N to P-N) . 53
7.1.4.2 MIMO Symmetric Transmit (Example N-E), MIMO Receive Star Plus CM . 54
7.1.4.3 MIMO Asymmetric Transmit (Example N-E), MIMO Receive Star Plus CM. 54
7.1.4.4 SISO Common Mode Transmit and SISO Common Mode Receive . 55
7.1.4.5 Alternative MIMO Mode Using Dual Wire Feed . 56
7.1.5 Circuit Diagram . 57
7.1.6 Measurement Results of STF410 Coupler Verification . 60
7.1.6.1 SISO . 60
7.1.6.2 MIMO Symmetric . 61
7.1.6.3 MIMO Delta Transmit to Star Receive . 62
7.1.6.4 Common Mode Reception . 64
7.1.6.5 Alternative MIMO Modes (Dual Wire Feed) . 65
7.2 Coaxial Cables . 65
7.3 Network Analyzer . 66
7.3.1 Agilent E5071B . 66
7.3.2 Agilent E5071C . 67
7.3.3 Rohde & Schwarz ZVB4 . 67
7.4 LISN or Filter to Isolate Measurement Devices from Mains . 68
7.5 Mains Filter . 68
7.5.1 Schematic Diagram . 69
7.5.2 Typical Impedances of Decoupling Components . 69
7.5.2.1 R/L Combinations - Mains Side . 69
7.5.2.2 Common Mode Choke - Instrument (NWA) Side (4 turns) . 69
7.5.3 Figures of Mains Filter . 69
7.6 Ground Plane . 70
Annex A: Bibliography . 71
History . 72

ETSI
5 ETSI TR 101 562-1 V1.3.1 (2012-02)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Powerline Telecommunications (PLT).
The present document is part 1 of a multi-part deliverable covering the MIMO PLT as identified below:
Part 1: "Measurement Methods of MIMO PLT";
Part 2: "Setup and Statistical Results of MIMO PLT EMI Measurements";
Part 3: "Setup and Statistical Results of MIMO PLT Channel and Noise Measurements".
Introduction
In order to study and compare MIMO (Multiple Input Multiple Output) characteristics of the LVDN network in
different countries, the STF 410 (Special Task Force) was set up. The present document is one of three parts of
TR 101 562 which present the findings of STF 410 research.
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6 ETSI TR 101 562-1 V1.3.1 (2012-02)
1 Scope
Convential PLT modems (SISO) use only the phase and neutral wire of the mains grid. MIMO PLT utilizes additionally
the protective earth wire.
The present document is an overview of the prevalence of the third wire in private homes and a description of the
measurement setup and equipment used to perform EMI, channel and noise measurements.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] Sartenaer, T. & Delogne, P., "Powerline Cables Modelling for Broadband Communications",
ISPLC 2001, pp. 331-337.
[i.2] R. Hashmat, P. Pagani, A; Zeddam, T. Chonavel, "MIMO Communications for Inhome PLC
Networks: Measurements and Results up to 100 MHz", IEEE International Symposium on Power
Line Communications and its Applications (ISPLC), Rio, Brasil, March 2010.
[i.3] A. Schwager, "Powerline Communications: Significant Technologies to Become Ready for
Integration" Doctoral Thesis at University of Duisburg-Essen, May 2010.
[i.4] ETSI TR 102 175 (V1.1.1): "PowerLine Telecommunications (PLT); Channel characterization and
measurement methods".
[i.5] Housing Statistics in the European Union 2010; The Hague: Ministry of the Interior and Kingdom
Relations; Edited by Kees Dol and Marietta Haffner, OTB Research Institute for the Built
Environment, Delft University of Technology; September 2010.
NOTE: Available at http://abonneren.rijksoverheid.nl/article/kennisplein-wwi/nieuwsbrief-kennisplein-wwi-
december-2010/housing-statistics-in-the-european-union-2010/428/3384?mode=html-mail.
[i.6] How we are housed: Results from the 1999 American Housing Survey; Summary of U.S. housing
market conditions (30 Aug. 2011).
NOTE: Available at http://www.huduser.org/periodicals/ushmc/fall00/summary-2.html.
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7 ETSI TR 101 562-1 V1.3.1 (2012-02)
[i.7] Canadian Housing Observer 2006; CMHC, ISBN 0-662-44559-7, adapted from Statistics Canada
(Census of Canada) (30 Aug. 2011).
NOTE: Available at http://www.cmhc-schl.gc.ca/odpub/pdf/65102.pdf.
[i.8] Wikipedia, free encyclopedia; 2010/2011.
NOTE: Available at http://en.wikipedia.org.
[i.9] ETSI TR 101 562-2 (V1.2.1): "Powerline Telecommunications (PLT); MIMO PLT;
Part 2: Setup and Statistical Results of MIMO PLT EMI Measurements".
[i.10] ETSI TR 101 562-3 (V1.1.1): "PowerLine Telecommunications (PLT); MIMO PLT;
Part 3: Setup and Statistical Results of MIMO PLT Channel and Noise Measurements".
[i.11] IEC 60906-1: "IEC system of plugs and socket-outlets for household and similar purposes -
Part 1: Plugs and socket-outlets 16 A 250 V a.c.".
[i.12] Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the
harmonisation of the laws of Member States relating to electrical equipment designed for use
within certain voltage limits.
[i.13] IEC 60364-1: "Low-voltage electrical installations - Part 1: Fundamental principles, assessment of
general characteristics, definitions".
3 Symbols and abbreviations
3.1 Symbols
For the purposes of the present document, the following symbols apply:
dB decibel (logarithmic unit)
dBm 10 * log (P / 1 mW)
Hz Hertz
L Inductance
m meter
MHz Mega Hz
nF nanoFarads
nH nanoHenry
R Resistor
Ω Ohm
Z Impedance
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Alternating Current
AMN Artificial Mains Network
BCA Building & Construction Authority
BNC Bayonet Nut Connector
BS British Standard
BSI British Standards International
C "Center point" of the Coupler
CEE Conformity certification of Electrical Equipment
CIS Commonwealth of Independent States
CM Common Mode
DC Direct Current
DM Differential Mode
E Protective Earth Contact
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8 ETSI TR 101 562-1 V1.3.1 (2012-02)
EC European Commission
EMI Electro Magnetic Interference
EP Connection E to P
EU European Union
GFCI Ground-Fault Circuit Interrupters
HSE Health and Safety Executive
IEC International Electrotechnical Commission
IF Intermediate frequency
IS International Standard
LISN Line Impedance Stabilization Network
LVDN Low Voltage Distribution Network
MEN Multiple Earthed Neutral
MIMO Multiple Input Multiple Output
N Neutral
NE Connection N to E
NEC National Electric Code
NWA Network Analyzer
P Phase
PE Protective Earth
PLC PowerLine Communication
PLT PowerLine Telecommunications
PME Protective Multiple Earthing
PN Connection P to N
PVC PolyVinyl Chloride
RCD Residual Current Device
Rx Receive
S Switch
SABS South African Bureau of Standardization
SI International System of Units
SISO Single Input Single Output
STF Special Task Force
T Transformer
t Turns
TTL Transverse Transfer Loss
Tx Transmit
USSR Union of Soviet Socialist Republics
3.2.1 Abbreviations Used for Feeding Styles
APN Signal feed mode: Dual wire feed (version C of clause 7.1.4.5) to input P||N E in figure 28
CM Signal feed mode: Common mode, P, N, E terminated to ground
EP Signal feed mode: DELTA (differential) between E and P, PN and NE terminated
EP-NET Signal feed mode: Differential between E and P, only NE terminated
EPNT Signal feed mode: DELTA (differential) between E and P, PN and NE not terminated
NE Signal feed mode: DELTA (differential) between N and E, PN and EP terminated
NE-EPT Signal feed mode: Differential between N and E, only EP terminated
NENT Signal feed mode: DELTA (differential) between N and E, PN and EP not terminated
PN Signal feed mode: DELTA (differential) between P and N, NE and EP terminated
PNE Signal feed mode: Dual wire feed (version C of clause 7.1.4.5) to input PN in figure 28
PNNT Signal feed mode: DELTA (differential) between P and N, NE and EP not terminated (SISO)
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9 ETSI TR 101 562-1 V1.3.1 (2012-02)
4 Major Project Phases
Table 1
No. Period Topic Event
01 Sept. 2010 Project organization STF 410 preparatory meeting
Definition of targets, what and how to measure Stuttgart, Germany
02 Nov 2010 Setup of MIMO PLT measurements (EMI, Several STF 410 phone conferences.
Channel and Noise) Drafting of measurement specification
st
03 Dec. 2010 Coupler to send and receive MIMO
1 version of the STF410 couplers
PLT signals developed
04 Jan 2011 and later Verification of couplers and filters developed for Couplers are used by STF410 experts
STF410.14 identical couplers are manufactured in field measurements in private
and shipped to the STF experts homes
05 March 2011 Agreement on STF410 logistics, when and where
to perform field measurements
st
06 April 2011 ETSI PLT#59
Approval of 1 TR on STF410 couplers
07 March 2011 to Field measurements in Spain, Germany, France,
June 2011 Belgium and the United Kingdom
08 June 2011 Statistical evaluation of results Several STF 410 phone conferences
nd
09 July 2011 ETSI PLT #60
Approval of 2 TR on EMI results
10 Oct. 2010 to Evaluation of the presence of PE wire worldwide
August 2011
11 June to August Drafting and STF 410 review and approval
2011 process
12 Sept. 2011 Presentation of Channel and Noise readings to ETSI PLT #61
ETSI PLT plenary
13 Oct 2011 Content of the 3 TR parts is revised and
rearranged.
14 Nov 2012 Approval of all 3 parts of TR 101 562 ETSI PLT #62

5 Motivation
PLT systems available today use only one transmission path between two outlets. It is the differential mode channel
between the phase (or live) and neutral contact of the mains. These systems are called SISO (Single Input Single
Output) modems. In contrast, MIMO PLT systems make use of the third wire, PE (Protective Earth), which provides
several transmission combinations for feeding and receiving signals into and from the LVDN. Various research
publications [i.1], [i.2], [i.3] describe up to 8 transmission paths that might be used simultaneously.
Channel measurements, as described in these publications, are verified by STF410. New electricity installations in
many countries of the world use 3 wires for connecting a single plug. Clause 6 provides information about the presence
of the PE wire.
All flats protected with RCD (residual current devices) must have a separate protective earth wire installed. In
Germany, for example, the protective earth has been mandatory for all new installations since the early 1970's. As
MIMO PLT modems also utilize the protective earth, they are able to alternately feed from phase to neutral (P - N),
phase to protective earth (P - PE) and neutral to protective earth (N - PE). The protective earth may be grounded inside
(e.g. at the foundations) or outside (at the transformer station) the building and provides low impedance for the 50 Hz
AC power. However, high frequency signal measurements show the PE wire to be a rather excellent communication
path which by no means represents a ground. This is due to the inductivity of the grounding wires.
If the differentially fed signals are converted to common mode, they propagate over the network, as well. For each pair
of outlets, the DM (Differential Mode) and the TTL (Transverse Transfer Loss) [i.4] attenuation is measured and
statistical comparisons are provided.
ETSI
10 ETSI TR 101 562-1 V1.3.1 (2012-02)
PLT MIMO Channel:
Feeding Receiving
�
P -P - NN
P -P - NN
N - PE
N - PE
P - PE
P - PE
CM
Figure 1: MIMO PLT Channel Matrix
Figure 1 shows the individual physical paths in a MIMO PLC channel. The DM path P-N at transmitter to P-N at
receiver is the traditional channel between two SISO modems. All other paths contribute to multiple input and multiple
output.
6 Worldwide Evaluation of the Presence of the
Protective Earth (PE) Wire in Residential Dwellings
Before evaluating the properties of the protective earth wire in private homes, it is important to consider where and with
which probability the third wire is likely to be found in a given country. Unfortunately this information is not available
in a harmonized way for all countries, so several different approaches were employed to collect this information:
• Study of individual grounding systems and investigations into which grounding systems are used in which
countries
• Creation of a list of AC wall socket types and where which one is used
• Researches when the regulation for the installation of the protective earth went into effect and produced an
estimate of how many electrical installations have taken place since then
• Searches for secondary information, e.g. worldwide sales numbers of RCDs
• Worldwide survey of data from electrical standardization committees and engineering clubs for each country
A map is presented at the end of this clause, which summarizes the presence of the PE wire in each country based on
the research mentioned above. It has to be noted that the results here do not reflect a complete, comprehensive and
comparable overview of the probability of PE wire installations.
The information collected in this clause was frequently derived from [i.8]. This reference is not given at all locations
where it is used.
6.1 Grounding Systems
In electricity supply systems, a "grounding system" defines the electrical potential of the conductors relative to that of
the Earth's conductive surface. The choice of grounding system has implications for the safety and electromagnetic
compatibility of the power supply. Note that regulations for grounding systems vary considerably among different
countries.
A protective earth connection ensures that all exposed conductive surfaces are at the same electrical potential as the
surface of the Earth, to avoid the risk of electric shock if a person touches a device in which an insulation fault has
occurred. It ensures, that in the case of an insulation fault (a "short circuit"), a very high current will surge, which will
trigger an over-current protection device (fuse, circuit breaker) that disconnects the power supply.
ETSI
Today: only PN PN
11 ETSI TR 101 562-1 V1.3.1 (2012-02)
A functional earth connection may carry a current during the normal operation of a device. Examples of such devices
are surge suppression and electromagnetic interference filters, some types of antennas and various measurement
instruments. Generally the protective earth is also used as a functional earth, though this requires care in some
situations.
International Standard IEC 60364-1 [i.13] distinguishes three families of grounding arrangements, using the two-letter
codes TN, TT and IT.
The first letter indicates the connection between earth and the power-supply equipment (generator or transformer):
T Direct connection of a point with earth (Latin: terra);
I No point is connected with earth (isolation), except perhaps via high impedance.
The second letter indicates the connection between earth and the electrical device being supplied:
T Direct connection of a point with earth;
N Direct connection to neutral at the origin of installation, which is connected to the earth.
6.1.1 TN Networks
In a TN earthing system, one of the points in the generator or transformer is connected with earth, usually at the star
point in a three-phase system. The body of the electrical device is connected with earth via this earth connection at the
transformer.
Figure 2: TN Networks
The protective earth (PE) is the conductor that connects the exposed metal parts of the consumer. The neutral (N)
conductor connects to the star point in a three phase system, or carries the return current in a single phase system. There
are three variants of TN systems:
TN-S, TN-C, TN-CS
ETSI
12 ETSI TR 101 562-1 V1.3.1 (2012-02)
6.1.1.1 TN−S
PE and N are separate conductors that are only connected together near the power source.

Figure 3: TN-S Network
Separate protective earth (PE) and neutral (N) conductors from transformer to consumer device, which do not connect
after the building distribution point.
6.1.1.2 TN−C
A combined PEN conductor fulfils the functions of both a PE and an N conductor, but this type of installation is rarely
used.
Figure 4: TN-C Networks
The combined PE and N conductor are connected all the way from the transformer to the consuming device.
6.1.1.3 TN−C−S
Part of the TN-C-S system uses a combined PEN conductor, which splits into separate PE and N lines. The combined
PEN conductor typically occurs between the substation and the entry point into the building, and separates in the service
head. This system, which connects the combined neutral-and-earth conductor to real earth at many locations to reduce
the risk of broken neutrals, is also known as "protective multiple earthing" (PME) in the UK and "multiple earthed
neutral" (MEN) is the designation of Australia's system.
ETSI
13 ETSI TR 101 562-1 V1.3.1 (2012-02)

Figure 5: TN-C-S Networks
Combined PEN conductor from transformer to building distribution point, but PE and N conductors separate in the
fixed indoor wiring and have flexible power cords.
6.1.2 TT Network
In a TT earthing system, consumer PE connections are provided by a local connection to earth, which is independent
from any earth connection at the generator. An advantage of a TT network is that there is no risk of a broken neutral.
In locations where power is distributed overhead and TT is used, installation earth conductors are not at risk should any
overhead distribution conductor be fractured by, say, a fallen tree or branch.
TT earthing systems were unattractive for general use, before RCD times, due to their lesser ability to accept high
currents in the event of a live-to-PE short circuit (in comparison to TN systems).However, residual current devices
mitigate this disadvantage, making the TT earthing system attractive for premises where all AC power circuits are
RCD-protected.
Figure 6: TT Network
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14 ETSI TR 101 562-1 V1.3.1 (2012-02)
6.1.3 IT Network
In an IT network, the distribution system has no connection to earth at all, or it has a high impedance connection which
is monitored by an insulation monitoring device. Environments supplied via engine-generators, e.g. laboratory rooms,
medical facilities, construction sites, repair workshops, mobile electrical installations, etc., where there is an increased
risk of insulation faults, often use an IT earthing arrangement supplied by insulation transformers. In order to mitigate
the two-fault issues with IT systems, isolation transformers should either supply only a small number of loads each
and/or be protected with an insulation monitoring device (generally used only by medical, railway or military IT
systems, due to cost).
Figure 7: IT Network
When an isolation problem occurs, the power is not cut, but the monitoring system detects the current leakage through
the high impedance and a warning light comes on to indicate that there is a problem. An assigned technician has to then
solve the problem. It is mandatory that he be available 24/7 as implied this grounding standard.
If a second problem occurs with a stronger current leak to earth, where both Phase & Neutral conductors in short-
circuit, then the power will be cut by another protection device, e.g. a fuse or circuit breaker.
6.1.4 Regulations of Earthing Networks
• According to the United States National Electrical Code and Canadian Electrical Code, the feed from the
distribution transformer uses a combined neutral and grounding conductor, but within the structure separate
neutral and protective earth conductors are used (TN-C-S). The neutral must be connected to the earth
(ground) conductor only on the supply side of the customer's disconnecting switch. Additional connections of
neutral to ground within the customer's wiring are prohibited.
• Japan is governed by PSE law, and uses TT earthing in most installations.
Most modern homes in Europe have a TN-C-S earthing system with a combined neutral and earth between the nearest
transformer substation and the service cut out (the fuse before the meter); and separate earth and neutral cores thereafter
in all internal wiring.
• Urban and suburban homes in the UK tend to have TN-S supplies, where the earth connection is delivered
through the lead sheath of the underground lead-and-paper cable.
• Older homes, worldwide, especially those built before the invention of residual-current circuit breakers and
wired home area networks, use an in-house TN-C arrangement. Today, this is no longer recommended
practice.
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15 ETSI TR 101 562-1 V1.3.1 (2012-02)
• In remote areas, where the cost of an additional PE conductor outweighs the cost of a local earth connection,
TT networks are commonly used in some countries, especially in older properties or in rural areas, where
safety might otherwise be threatened by the fracture of an overhead PE conductor(e.g. by a fallen tree branch).
Within areas that mainly utilize TN-C-S systems, individual properties can be seen to have a TT supply, if the
property is considered unsuitable for TN-C-S.
• Australia and Israel both use the TN-C-S systems. However, additional wiring rules require that each customer
have separate connections to earth via a water pipe bond (where metallic water pipes enter the consumer's
premises) and a dedicated earth electrode. In Australia, new installations must also be bonded to the concrete
in the foundation in order to reinforce the connection to the earth conductor (AS3000) under areas of the
premises which might become wet, such as bathrooms; typically, this increases the earthing size and creates an
equipotential plane. It is not uncommon to only find the water pipe bond in older installations, which is
allowed to remain as such, until upgrade and renovation work is done, in which case the additional earth
electrode must be installed. Protective earth and neutral conductors are combined up until the consumer's
neutral link (located on the customer's side of the electricity meter's neutral connection) - beyond this point,
the protective earth and neutral conductors are separate.
6.2 Wall Socket Types Used in Various Countries
AC power plugs and sockets are devices for connecting removable, electrically operated consumer devices to a power
supply.
A plug connects mechanically to a matching socket. Plugs are mostly or completely male, while sockets are mostly or
completely female; the plug has protruding prongs or pins that fit into matching slots or holes in the socket. Generally, a
plug is the movable connector attached to the power cord of an electrically operated device, and the socket is a fixture
on equipment or a building structure. Wall-mounted sockets are also called receptacles, outlets, or power points.
To reduce the risk of electric shock, plug and socket systems can incorporate a variety of safety features. For example,
sockets can be designed to accept only compatible plugs and reject all others, whereas others are designed so that a
dangerous voltage is never present on an exposed contact. Exposed contacts in some sockets are used for grounding.
Every commonly-used power outlet has two or three wired contacts. The contacts may be steel or brass, and may be
plated with zinc, tin, or nickel. Both live and neutral contacts typically carry current from the source to the load and
from the load to the source, changing direction 50-60 times per second, since alternating current (AC) is predominantly
used in energy distribution networks vs. direct current (DC = unidirectional). However only the neutral contact remains
at or very near the voltage potential of the earth, while the potential of the live contact changes sinusoidally, for
example -320 V to +320 V (peak-to-peak). Many outlets and plugs also have a third contact for a connection to earth
ground, intended to protect against insulation failure of the connected device. A common approach is for electrical
sockets to have three holes, which can accommodate either 3-pin earthed or 2-pin non-earthed plugs.
6.2.1 3 Pin Type Sockets
The types B, H, I, J, K and L use PE third pin (type B accepts type A plugs and types H, J, K and L accept type C). The
"Europlug" (type C) will fit type E and F sockets, and the earthed type E/F 2-pin plugs will fit type C (and certain
hybrid) sockets, without making earthing contact. Types D, G and M plugs are exclusively 3-pin, used for both earthed
and non-earthed appliances.
ETSI
16 ETSI TR 101 562-1 V1.3.1 (2012-02)
Table 2: Comparison of Sockets
Type Socket standard Power rating Grounded Polarised Fused Insulated pins
NEMA 1-15 unpolarised 15 A/125 V No No No No
A NEMA 1-15 polarised 15 A/125 V No Yes No No
JIS C 8303, Class II 15 A/100 V No No No No
Yes
NEMA 5-15 15 A/125 V Yes No No
(Note 1)
Yes
B NEMA 5-20 20 A/125 V Yes No No
(Note 1)
Yes
JIS C 8303, Class I 15 A/100 V Yes No No
(Note 1)
CEE 7/16 (Europlug) 2.5 A/250 V No No No Yes
No
CEE 7/17 16 A/250 V No No No
C (Note 1)
6 A/250 V
GOST 7396 C 1 No No No No
16 A/250 V
2 A/250 V
BS 546 (2 pin) No No No No
5 A/250 V = BS 4573
2 A/250 V
D
5 A/250 V
BS 546 (3 pin) Yes Yes No No
15 A/250 V = SABS 164
30 A/250 V
Yes No
E CEE 7/5 16 A/250 V Yes No
(Note 1) (Note 1)
Yes No
F CEE 7/4 (Schuko) 16 A/250 V No No
(Note 1) (Note 1)
Yes Yes No
E+F CEE 7/7 16 A/250 V No
(Note 1) (Note 3) (Note 1)
G BS 1363, IS 401 & 411, MS 589, SS 145 13 A/230-240 V Yes Yes Yes Yes

Yes
SI 32 16 A/250 V Yes No No
(Note 3)
H
TIS 166-2549 16 A/250 V Yes Yes No Yes
10 A/240 V
15 A/240 V
Yes
AS/NZS 3112 20 A/240 V Yes No Yes
(Note 1)
25 A/240 V
I
32 A/240 V
CPCS-CCC 10 A/250 V Yes Yes No No
IRAM 2073 10 A/250 V Yes Yes No No
10 A/250 V Yes
J SEV 1011 Yes No No
16 A/250 V (Note 1)
Yes
K Section 107-2-D1 13 A/250 V Yes No No
(Note 1)
10 A/250 V Yes
L CEI 23-16/VII No No Yes
16 A/250 V (Note 1)
IEC 60906-1 [i.11] (2 pin) 10 A and 20 A/250 V No No No Yes
-
Yes
IEC 60906-1 [i.11] (3 pin) 10 A and 20 A/250 V Yes No Yes
(Note 1)
NOTE 1: There are common ungrounded plugs that work with the grounded sockets of this type.
NOTE 2: Deep-wall socket prevents human contact with pins.
NOTE 3: Plug can only be inserted one way with French socket of type E, but lack of wiring convention means that the
type is not polarized in practice.
NOTE 4: There are some CEE 7/17 plugs with a special shape which are polarized when used with the French socket of
type E (mechanically only).
NOTE 5: Newer sockets can accept ungrounded Type C Europlugs.

ETSI
17 ETSI TR 101 562-1 V1.3.1 (2012-02)
Information regarding the use of PE in each country is included in the table above, alongside the type of sockets used.
For more information, please view links below.
http://www.interpower.com/icl2/guide.htm
http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets

Figure 8: Socket Types World Map
6.2.2 Countries in which PE Grounding is Not in Use
According to the available information on the different socket types in use, it can be concluded that PE is most likely
not used in the following countries:
• Angola
• Egypt
• Eritrea
• Gabon
• Georgia
• Guinea-Bissau
• Mauritania
• North Korea
• Paraguay
• Somalia
• Togo
ETSI
18 ETSI TR 101 562-1 V1.3.1 (2012-02)
6.2.3 Countries where PE Type Sockets are Exclusively Used
It can also be concluded that PE should be exclusively used in the following countries which use D, I, G and J type
sockets:
Australia, Bahrain, Bhutan, Botswana, Brunei, Chad, Cook Islands, Cyprus, Dominica, Falkland Islands, Fiji, Gambia,
Ghana, Gibraltar, Grenada, Hong Kong, Ireland, Isle of Man, Kenya, Kiribati, Kuwait, Lesotho, Libya, Macau (China),
Malawi, Malta, Mauritius, Namibia, Nauru, New Caledonia, New Zealand, Nigeria, Papua New Guinea, Qatar, Reunion
Island (France), St Lucia, St Pierre and Miquelon (France), Samoa, Seychelles islands, Sierra Leone, Sri Lanka,
Swaziland, Tanzania, Tonga, Turkmenistan, Uganda, United Kingdom, Vanuatu, Zimbabwe.
For these countries, it can be assumed that the percentage of dwellings equipped with Protective Earth wire is high
(around 100 %).
6.3 Regulation Approach to Estimate Presence of Protective
Earth
In the following clause information from some countries are collected in a harmonized way. Further information on a
few countries is given later by STF 410 experts, who have had access to more in depth information. Please see the
individual sources for this information.
6.3.1 European Countries
Table 3 lists the total number of dwellings for several European countries from census data sourced from Housing
Statistics in the European Union 2010 [i.5].
Table 3: Number of Private Households (x 1 000) for a few European Countries
1980 1990
...