2.2.1 European Voltage Harmonisation
The nominal European voltage is now 230V 50 Hz (formerly 240V in
UK, 220V in the rest of Europe) but this does not mean there has
been a real change in the supply.
Instead, the new "harmonised voltage limits" in Europe
are now:
230V -10% +6% (i.e. 207.0 V-243.8 V)
in most of Europe (the former 220V nominal countries), and
230V -6% +10% (i.e. 216.2 V - 253.0 V)
in UK (former 240V nominal)
This is really a fudge and means there is no real change of
supply voltage, only a change in the "label", with no
incentive for electricity supply companies to actually change the
supply voltage.
To cope with both sets of limits an equipment will therefore need
to cover 230V +/-10% i.e. 207-253V. This will actually become the
official limit for the whole of the EU in 2003.
2.2.2 North America
ANSI C84.1 "Electric Power Systems and Equipment - Voltage
Ratings (60 Hz) sets the preferred nominal voltage at 120V and
allows a range of 114 - 126V (240V nominal, range 228 - 252V).
Equivalent Canadian spec is CAN3-C235.
Voltage at a 120 volt nominal single phase receptacle should be
110 to 125V under normal conditions.
However, the California Public Utilities Commission has specified
that the service voltage shall be kept in the range 114-120V,
with some exceptions. This was done because some studies showed a
reduction in energy consumption at the lower voltages.
2.2.3 Rest of the World
Australia
Currently, Australia is on 240V, +6%, -6%. Australian mains
voltage is due to change in line with European voltages.
Australian Standard AS60038:2000 "Standard Voltages"
which replaces AS2926:1987 provides for the "nominal systems
voltage" of 230/400V 50Hz and recommends that the voltage at
the point of supply should not differ from the nominal voltage of
the system by #\par }{\plain \fs20 \cf2\f1\fs20 more than +10%
-6%.
A listing of nominal voltage/frequency and plug/socket types used
in many countries is given at http://www.cris.com/~kropla/electric2.htm
Other world voltage listings:
"Electric Current Abroad" - http://www.ita.doc.gov/td/machinery/ecabroad
http://www.50hz.com/pwchrt.htm
http://www.clary.com/Service/IntVoltage.asp
http://www.panelcomponents.com/guide.htm
The following official publications are also available:
Electric Current Abroad, 1998 Edition
Lists the characteristics of
electric current available and types of plugs used in most
countries. It is an update of a
similar handbook published in 1991. Gives the type
of current (AC or DC), number
of phases, frequency, and voltage, and the
stability of the frequency and the number of wires to a
commercial or residential installation.
US Department of Commerce, NTIS (National Technical Information
Service), 35 pp.
NTIS Order Number PB98-156466INP.
US, Canada, Mexico $10 ea + $5 handling per order, elsewhere $20
ea +$10 handling.
NTIS sales desk
Tel 1-800-553-6847 or (703)-605-6000
Fax (703) 605-6900
NTIS 5285 Port Royal Road, Springfield, VA 22161, USA
URL: http://www.ntis.gov
WORLD ELECTRICITY SUPPLIES (New issue 1998)
Covers over 200 countries. Detailed tables list voltage,
frequency and voltage tolerances for household, commercial and
industrial sectors, including the nature of the supply, e.g.
availability of a neutral and earth phasing for each country.
BSI reference TH20338, L50.00 (non-members), £40.00 (members)
Int'l Product Safety Bookshop (see section
1.8) $87.50 pp in US
Electrical Plugs: an International Survey (1993)
BSI reference TH20348, L62.00 (non-members), L49.60 (members)
British Standards Institution, 389 Chiswick High Road, London W4
4AL, UK
Tel: +44 181 996 9001
Fax: +44 181 996 7001
http://www.bsi.org.uk
2.2.4 Power Quality
It is not possible here to give a tutorial on the rapidly
expanding subject of Power Quality. The fundamental
specifications for the quality of the supply are:
Europe EN 50160
UK G5/3 (new version G5/4 in draft)
US IEEE 519
The major European product standard is EN 61000-3-2 which will
affect most electrical products, including IT, audio and TV,
manufactured after January 1, 2001. This standard will replace EN
60555-2 (IEC 555) which has a more limited scope. However watch
the newsgroup and technical press for developments as EN
61000-3-2 is still under debate. A particularly helpful note by
John Woodgate, "The truth about IEC 61000-3-2 and -3, and
their EN clones" is available from his website http://www.jmwa.demon.co.uk
The Copper Development Association has published a very helpful Good
Practice Guide to power quality problems and the electrical
design of installations, including a comprehensive section on
harmonics and their amelioration, at: http://www.cda.org.uk/Megab2/elecapps/pub123/index.htm
Prof Alessandro Ferrero's website provides many useful references
about power quality, harmonics, etc at: http://www.etec.polimi.it/harmonics