Electrical Engineering

# What is the nominal supply voltage?

001 ###### 2011-11-11 18:40:28

The term, 'nominal', simply means 'named'. For example, the nominal supply voltage for a residence in the UK is 230 V. But this doesn't mean that the actual supply voltage is 230 V, because the supply voltage is allowed to vary by -6% and +10% of the nominal voltage. In other words, the actual voltage could be anywhere within the range of 216.2 V to 253 V. In fact, during periods of heavy load, the actual voltage would tend towards the lower end of this range, whereas during periods of higher load, the actual voltage would vary towards the upper end.

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## Related Questions It is the rated voltage of an electric equipment. It is the voltage at which the device is designed to operate.Another AnswerNominal means 'named'. So a nominal voltage is the 'named' voltage. For example, the nominal voltage of the supply system in Britain is 230 V. But its actual value is allowed to vary between 216.2 V and 253.0 V. The nominal voltage for the UK 230 V (+10/-6%). The nominal mains voltage in the UK is 230VAC, 50 Hz. The nominal voltage of the UK supply system is 230 V. Nominal voltage is the 'named' voltage -for example, the nominal supply voltage in the UK is 230 V. But this is not necessarily the actual voltage at a particular time. A nominal voltage is normally expressed together with the percentage by which it is permitted to vary from that stated value. For example, in the UK, the nominal voltage is expressed as: 230 V +10% / -6% --in other words it is allowed to vary between 216.2 and 253 V.The term, operating voltage, isn't actually defined anywhere, but is usually taken to mean the actual voltage supplied to a device at any particular instant, and this should always fall within the allowable range of the supply system's specified nominal voltage. The operating voltage can be found simply by measuring it with a voltmeter. It can be used for anything with a nominal 12 v requirement. In cars everything runs on a nominal voltage of 12 v but is designed to run on 13.8 v which is the voltage when the car is running. .230kvAnswerThe nominal supply voltage to a residence depends on the national electrical standards in the country in which you live, but no residential single-phase supply exist in the kilovolt range. European countries have a standard nominal voltage of 230 V (which you could express as 0.230 kV, if you really wanted to!) and the US and Canada have a nominal 240/120 V supply voltage.And the correct symbol for kilovolts is 'kV', not'kv'. The standard nominal voltage in Canada for a single-phase residential supply is 240/120-V split-phase supply. Power supply voltages vary with the amount of load placed on them. In many countries the supply voltage has a nominal voltage and a plus or minus tolerance. In the UK the nominal voltage is 230 v but the allowable variation is -6% +10%, in other words 216-253. At my house the voltage is usually between about 236 and 253 volts. The word nominal means the lowest possible safe amount. So, nominal current or nominal voltage is the lowest amount necessary to perform an electrical function like keeping a light turned on.AnswerThe original answer is incorrect. 'Nominal' simply means 'named'. So a 'nominal voltage' is the 'named voltage', as opposed to an 'actual voltage'. For example, the nominal voltage of residential supplies in the UK is 230 V; however, this value is allowed to vary between +10/-6% of the nominal voltage. In other words, a nominal voltage of 230 V may vary between 216 V and 253 V. It depends on where you live, as most countries have their own standards. In the UK, for example, the nominal (named) mains voltage is 230 V, but it is allowed to vary between +10% and -6%. The nominal frequency of this voltage is 50 Hz, and this is allowed to vary between +/-1%. In North America, the standard nominal supply voltage is 120 V at 60 Hz. 230 V is the standard nominal voltage in the UK. 'Nominal' means the 'stated' voltage, but this is allowed to vary, under government legislation, between +10% and -6%, which means it is allowed to drop to 216 V.The motor's rated voltage of 208 V is also a nominal voltage, but is not a standard UK nominal voltage so, without knowing what in which country the motor is manufactured, we'll assume that it is allowed to vary between, say, +5% to -5%. This means that it can operate at voltages up to 218 V. If it's allowed to vary between, say, +10% and -10%, then it can be operated up to 229 V.So there is an overlap between the nominal voltage of the supply and the rated nominal voltage of the motor so, in all likelihood, the motor should be able to run with a 230-V supply. On the other hand, there will be times when the supply voltage will exceed the upper limit of the motor's nominal voltage, and this may -over time- lead to a breakdown in its insulation and its ultimate failure. The answer to this question depends entirely on where you live. All voltages quoted are 'nominal', or 'named', voltages and not the actual voltage as you would measure it with a voltmeter. National regulations stipulate how much these nominal voltages may vary.For example, in the UK, the nominal voltage is 230 V, and the allowable variation is between -6% and +10%. So, the maximum (actual) allowable voltage is 253 V.In some residences, e.g. Cyprus, a three-phase supply is common for residences, in which case the maximum nominal line-voltage is 400 V, with a nominal phase-voltageis 230 V. 'Nominal' simply means 'named'. So a 'nominal current' is simply a 'named current' and a 'nominal voltage' is simply a 'named voltage'. As opposed to 'actual'. For example, in Europe, the 'nominal voltage' is 230 V, but this doesn't mean that the voltage IS necessarily 230 V, because it is allowed, under the various statutes, to vary above or below the nominal value by a certain percentage (between -6% and +10%, for example, in the UK). The same applies to a nominal current -for example, a kettle's nameplate may specify that the kettle or some other appliance draws a nominal current of, say, 12 A. But, in practice, the actual current will vary due to variations in supply voltage. In my country, the standard mains supply is nominal 120/240 volts AC 60 Hz. The nominal voltage of a Duracell DL123 battery is 3 (lithium) nominal volts or 3.6 (Li-ion) nominal volts. 'Nominal' means 'named'. So a 'nominal' voltage is the named voltage of a system. For example, when we talk about a 120-V or 240-V system, we are describing their nominal values, not their actual values which can change from moment to moment. Short answerHouse in US = 156V peakHouse in Europe = 325V peakLong AnswerAC voltages are usually identified by their RMS voltage. This is a mathematical calculation of the "average" or DC equivalent voltage. It is smaller than the peak voltage by a factor of about 0.707 for a sine wave AC which is the normal type.The actual peak voltage in your house depends on a number of factors. The most important being what the nominal supply voltage is in your area.The US typically uses a nominal voltage of 110V RMS = 156V peakMost of Europe uses a nominal voltage of 230V RMS = 325V peakActual voltages in a particular house can vary significantly from nominal. Some specifications call for +/-10% from nominal. The difference is caused by voltage drops at various stages in electricity transmission. There can also be variations due to shortages of supply, etc. Yes. These values are not exact, your voltage could actually be between about 220 and 240 at any given time as long as you're within that range it's okay.Additional AnswerThe figures for voltage/current/power that you see printed on lamps, or on appliance data plates, are termed nominal values, where 'nominal' means 'named'. So if a lamp has a nominal value of, say, 240 V, this doesn't mean that the lamp will necessarily be subjected to exactly 240 V when it is plugged into a supply.Since 1st January, 1995, the UK's nominal supply voltage has been specified as 230 V -but the actual voltage is allowed to vary between -6% and +10% of this nominal figure -in other words between 216.2 V - 253.0 V. So, as you can see, it is quite normal for a lamp with a nominal voltage of 230 V to operate at an actual voltage of 240 V. The voltage of three phase is 415v and the colours are brown black and greyAnswerThe nominal line voltage is 400 V, and the nominal phase voltage is 230 V. The standard nominal mains supply everywhere in the USA is 120 volts AC, 60 Hz. A zener diode has a voltage when it reachesbreak over it may be 5v 12vor other voltage as manufactured. The manufacture will produce a 5v zener or is it? This voltage can change from device to device but the mean or nominal voltage will be as close as 5v as possible. So when buying a 5v zener do not expect 5v absolute but a nominal 5 v ZENERS are designed for a specific voltage [ THEREFORE NOMINAL] as mentioned above . depends on the voltage required it can be bought within a specific voltage -/+ a % of the breakdown 415 V used to be the standard nominal line voltage for three-phase systems in the UK. This value of line voltage resulted in a nominal corresponding phase voltage of 240 V required for residences, etc. Remember, a line voltage is 1.732 larger than the phase voltage.However, since 1995, in order to 'harmonise' with other European Union countries, the UK's nominal line voltage has since been changed to 400 V, giving a nominal phase voltage of 230 V.'Nominal' means 'named'; it is not necessarily the actualvoltage you would measure using a voltmeter. This is because government legislation allows supply voltages vary, within specified limits, either side of the stated nominal voltage.Although the 'nominal' value has been changed from 240 V to 230 V, no 'actual' change has actually taken place. Instead, the UK's voltage standard has simply been changed from 240 V (+/- 6%) to 230 V (+10/-6%) -thus ensuring that the EU harmonisation requirement is met without the need for any actual changes to the electricity supply system! The rated voltage of a motor listed on the nameplate is called the terminal voltage. This indicates the actual voltage on the motors terminals at which at which the manufacturer designed to operate. Whereas, Nominal voltage is the design or configuration voltage of the electricity distribution system. 250 V is not a nominal voltage used in Europe or in North America, although it may be elsewhere in the world. If so, then, yes, there will be 100-W lamps marketed for that particular voltage in that particular part of the world.The nominal voltage in Europe is 230 V and the nominal voltage (for lamps) in North America is 120 V. So, in Europe and North America, 100-W lamps are rated at 230 V and 120 V respectively.

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