# 220V is it Rms or peak ??

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#### ysenthilece

##### Member level 3 220v rms

sorry for this silly question .but i can't find the answer anywhere..

#### IanP #### jeffttan

##### Member level 2 220v rms?

It is in RMS... same as 110V in power lines

#### electron_boy

##### Full Member level 3 110v vrms

its RMS

• macellan

### macellan

Points: 2

#### electronics_kumar relation between rms and peak

moreover .why it should be RMS ....why should not as +340V,-340V while referring

#### Eric Best

##### Member level 4 relation between rms and peak voltage

electronics_kumar said:
moreover .why it should be RMS ....why should not as +340V,-340V while referring

because, simply said, this value (rms) is sort of a mean value which is engaged in, especially, power calculations, etc.

e.g. for resistive loads power can be simply calculated multiplying current and voltage rms values: P = Vrms * Irms, whatever waveform it represents!
(or P = Vrms*Vrms/Rload, or P = Irms*Irms*Rload, likewise with dc values)

Referring to the peak value (only for sine waveforms!!!) power would be calculated:
P = Vpeak * Ipeak / 2 (or P = Vrms*Vrms/(2*Rload), or P = Irms*Irms*Rload/2)

It allows to compare or evaluate "power contents" of different waveforms in a way, while its peak values don't give any information as to this point.

Best Regards
Eric

#### the_risk_master rms 220v

Try to grab a Digital Multimeter (select it as to measure AC voltage with range of at least higher on what you are expected to measure) Now read the Meter, it should read 220V (note all meter device should read RMS values)

#### Eric Best

##### Member level 4 220 vrms

the_risk_master said:
Try to grab a Digital Multimeter (select it as to measure AC voltage with range of at least higher on what you are expected to measure) Now read the Meter, it should read 220V (note all meter device should read RMS values)

To tell the truth the above is not always true. Multimeters usually display rms value but this fact does not mean they really measure it. If they do, you can see the notice "True RMS" somewhere on the device and such a device is also appropriately more expensive (it requires a built-in rms converter). Other devices usually measure peak or mean value of a rectified waveform and take advantage of the fact that the relations between peak/mean and rms (root mean square) values for a known waveform, in this case sine wave, are constants so that they can recalculate it and display. This fact implies that such a device displays the more inaccurate value (sometimes really nonsens) the more the measured waveform "differs" from sine wave.
For instance waveforms in circuits with a phase controlled SCR (thyristor or triac) give quite big errors measured with non-true rms devices.

Just for interest, the mentioned values are defined as follows:
For periodic waveforms v(t):

mean value = $\frac{1}{T}\int_0^T{v(t)dt}$

rms value = $\sqrt{\frac{1}{T}\int_0^T{v^2(t)dt}}$,

where T is the time period.

Sine wave:
If v(t) = M×sin(ωt),
where M ... peak value of the sine wave,
ω = $2\p f$ =&nbsp$\frac{2\p}{T}$ ... circular frequency, we obtain:

mean value = 0

if fully rectified, then

mean value = $\frac{2M}{\p}$ = 0.637M ... relation between mean (fully rectified) and peak value

rms value = $\frac{M}{\sqrt{2}}$ = 0.707M ... relation between rms and peak value

rms/mean (fully rect.) = $\frac{\p}{2\sqrt{2}}$ = 0.707/0.637 = 1.11 ... relation between rms and mean value of fully rectified sine wave

Best Regards
Eric

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#### xjackal

##### Full Member level 3 sin rms peak

Root Mean Square

#### ziyas

##### Member level 1 220 v peak to peak

ysenthilece said:
sorry for this silly question .but i can't find the answer anywhere..
this value is its rms it means root mean square so we calculate power from this values of voltage and current directly

#### ba33e

##### Newbie level 1 relation between rms and peak value

220 is rms.peak voltage is 1.4*220=308v

#### Ilokesh

##### Newbie level 3 rms voltage 220v

it is a RMS voltage

#### Yarafat

##### Junior Member level 3 i rms i peak

it is exaclty rms (root mean square) and it peak voltage is √2×220 (v).

#### sivakumar_tumma

##### Full Member level 4 rms and peak to peak

RMS VALUE

#### Eric Best

##### Member level 4 it(rms) scr calculation

Are you collecting points or what?

STOP these stupid messages, everybody already KNOWS it is rms!!!

#### maharshi_qis

##### Full Member level 5 calculate 220 rms peak value

if its a sine wave its rms value..
if its a nonsinusoidal wave it wont be RMS...any way becoz every wave can be converted as composition of sine wave there is a true rms meter which gives rms for any wave..gen all ac and dc volts xpressed in rms ..

#### aash32

##### Newbie level 6 310v sine rms

It should be rms.

#### vaibhav.k 26 vrms vs peak

Its RMS .Please check BL thereja u can get all the details.

#### FANT 220v rms peak

It is RMS, the peak voltage is RMS * sqare root o f2, say about 310 V.
The multimeters ( low price ) usually rectify the voltage ( taking the peak voltage ) and then they divide it by SQRT of 2.

Mandi

#### asas

##### Newbie level 4 p=vrms*irms

It's RMS!
Low price multimeters aren't True RMS, but if the signal you are messuring it's a Sine Wave there's no problem!! If not, the values shown would not be correct......... Status
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