Can somebody explain the importance of volt drop to me and why its so critical. The regs mention it several times and go into a lot of detail about it, even differentiating between power and lighting circuits. They have also altered the Zs values that we all knew off by heart on the back of voltage drop or variation. We have a nominal 230V on UK supplies and in all the times I have ever measured a voltage it has always been more than this coupled with the fact that most things now seem to have a switched mode power supply and will work on probably any voltage, including probably all this new fangeld LED lighting. This isn't my main query though, I was wondering why, when we have a nominal 230 volts and volt drop is so critical, then why are we not only allowed to fit these but we are actively encouraged to do so? https://www.google.co.uk/webhp?sour...ser&safe=off&tbm=shop&spd=7428062033722427235 So I have an incoming voltage of 230 therefore I cant have any less than 223 volts at a light fitting but I can fit the above and have less than 220, in a topsy turvy world even this makes no sense to me. I must be missing something
230V is RMS and so around 30% less than peak on the sine wave. Can't be arsed with the rest of the question.
230V is RMS and so around 30% less than peak on the sine wave. Can't be arsed with the rest of the question. Its whatever it shows on my meter smart ****.
Stated voltage is RMS, your meter could be reading peak voltage, If you don't know the difference you shouldn't be playing with it.
RMS voltage is just a red herring, 230V is the value we are given that is fed into our homes and the figure that most meters will read, if the voltage coming in is 238V (RMS) then the meter will read 238V (RMS), the true peak value is never given or measured.
Voltage drop only becomes a real issue, I think, when you draw a largish current. For most 'switching' power supply thingies, it chust won't be an issue, I guess.
Nice selective quoting, the sign of a true troll. So meter maid explain why we can fit a voltage optimiser but cant use a cable that may drop the voltage slightly even if no optimiser is fitted.
Loading - an appliance drawing say 20 amps @ 230v. How much will it draw at say 200v? If its fed with a cable with neglible headroom then things are not correct.,
It is really simple, Peter, when you consider basics. All materials that are electrical conductors have a resistance to the current. If it were not such an expensive metal, Silver is in fact the best conductor with least resistance to current. Copper is used because costs are comparatively reasonable. A voltage at the delivery is going to reduce towards the end of a circuit due to the combined resistance of the conductor. Length and cross sectional area dictate how much voltage will be lost and it is a known quantity based on the properties of the conductor. Ohms Law ties all the properties together. So, knowing the resistance for the conductor per meter means the resistance is increasing along the length. As long as the resistance doesn't exceed a certain value the reduction in the voltage can be controlled. R=V/I so as the resistance increases the voltage reduces to keep the equation balanced. In order to keep the voltage within the acceptable tolerance you have two choices. Either limit the resistance or reduce the current. If the voltage drops below the acceptable minimum then this can cause problems with electrical equipment not having sufficient voltage for it to operate. Lighting will go too dim, that's why it is limited to 3% vd, greater than 5% is considered a problem for operating electrical equipment. Hope I have explained this.
In the main it's the ballast controlled fluorescent tube where a small change in voltage will cause a large change in the current used. I got caught out 110 volt 16 amp supply using 60W fittings quick calculation I should be able to run 25 fittings off 16 amp. 0.55 amp each that's 13.6 amp so a couple of amp to play with. However when fitted it tripped and a clamp-on meter showed 22 amp. So the first 20 fittings had the auto transformer settings set to 127 volt with last 5 at 110 volt then total current 15 amp well within the limits. With all set at 127 volt then the volt drop on cable resulted in last 2 or 3 not working. Today with HF ballast units this is not required. So with LED lighting and inverter ballast (HF) with a typical voltage range of 150 ~ 250 volt there is no requirement to centrally control the voltage. More and more switch mode power supplies and inverters mean voltage is not as important as it was. About the last is the fridge and freezer where under voltage can cause the motor overload to operate more than it should and cause early failure most fridges and freezers state do not use with an extension lead. And even they are now moving to three phase motors and inverter control. So 10 years ago there may have been a point for the use of voltage optimisers today they are a waist of money and could damage and refrigeration units so should be avoided.
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