230volt vs 240volt

[IQ Electrical]

Can you elaborate?

The DNO's have a balancing act on the LV side whereby a supply close to a transformer might have a measured voltage of say 240 Volts.

The supply 3 miles down the road has a measured voltage of say 220 Volts.

You then drop the supply voltage and all subsequent supplies are affected and at the end of the distribution lines loads like fluorescent lighting can't strike up.

 

[telectrix]

and that's where DNOs make a killing. "205volts, mr. customer, that will never do. we will give you a 3 phase supply to cure the problem £15,000 OK?"

 

[johnboy6083]

in reality, if your near a local transformer, then your voltage is going to be nearer 250. is got to be this high, without massivley increasing the cable sizes, or putting in more transformers, and asscoiated HV supplies.

 

[IQ Electrical]

in reality, if your near a local transformer, then your voltage is going to be nearer 250. is got to be this high, without massivley increasing the cable sizes, or putting in more transformers, and asscoiated HV supplies.

That's true, I was just illustrating the cumulative effect of a 10 volt drop in nominal voltage.

 

[johnboy6083]

i didnt think for a second that i was correcting you mate, just adding a comment of my own. in new buildings ive regularly measured 253v

 

[Marvo]

The DNO's have a balancing act on the LV side whereby a supply close to a transformer might have a measured voltage of say 240 Volts.

The supply 3 miles down the road has a measured voltage of say 220 Volts.

You then drop the supply voltage and all subsequent supplies are affected and at the end of the distribution lines loads like fluorescent lighting can't strike up.

from the op

they run a 230 volt/50hz +10%/-6% system

This means the DNO should have max 243v at the lv side of their tx and they could supply a distance of such that results in 216 volts at the CU of furthest premises. If they can't achieve these figures then they have an infrastructure problem which shouldn't be compensated for by upping the voltage at the expense of peak loads. Surely this isjust robbing Peter to pay Paul??.

 

[telectrix]

till they all switch on their 35kwatt cookers at tea time, then you'll see a bit of a drop.

 

[IQ Electrical]

i didnt think for a second that i was correcting you mate, just adding a comment of my own. in new buildings ive regularly measured 253v

You're right, overvoltage is our most popular 'fail' on BS 50160 power quality surveys.

Followed closely by undervoltage out in the sticks.

 

[MarkieSparkie]

Under the Cenelec HD472S2 " Nominal Voltages for Low Voltage Public Networks" harmonization agreement all public networks in the EU were due to re-standardise at +-10% of nominal supply voltage on 1st January 2008. This did not happen, in the UK at least, and is still to be implemented. It's all gone very quiet on this subject. Does anybody know why the delay? Is it just UK out of step (for a change) with EU harmonization?

 

[johnboy6083]

I reckon it will be the cost implications of harmonsation. I think we would be talking millions upon millions of pounds, and that will all be passed down to us, the consumers.

 

[nickblake]

i went to lanzerotee a few years ago go more pics of dodgy electrics than pics of the resort think its about time europe comes into line with the uk ........first they can start by driving on the left , trucks and buses first if that goes ok then the cars ...............hehe

 

[malcolmsanford]

i went to lanzerotee a few years ago go more pics of dodgy electrics than pics of the resort think its about time europe comes into line with the uk ........first they can start by driving on the left , trucks and buses first if that goes ok then the cars ...............hehe

You laugh at home I have a clipping from a newspaper from a copper mining country in Africa taken from the 80's which decided to ditch it's colonial past and start to drive on the right.

It reads something like from midnight 18th March(sic) all vehicles with odd number plates will drive on the right, but to save congestion even numbers will start on midnight 19th March(sic)..........................luckily this was posted sometime in Feb and the schedule was hastily changed ..........................but luckily I was sent it by a former workmate.

 

[Jazza]

if the voltage in your house falls outside the range that is stated by this "HARMONIZATION" does that mean you could pursue the electricity board to sort it out? speaking in a purely hypothetical sense here.

is this a ESQCR fail if it is the case in your house?

 

[IQ Electrical]

if the voltage in your house falls outside the range that is stated by this "HARMONIZATION" does that mean you could pursue the electricity board to sort it out? speaking in a purely hypothetical sense here.

is this a ESQCR fail if it is the case in your house?

It's the case with any supply, it must fall within the tolerances defined in BS 50160.

We do a lot of power quality tests to BS 50160, primarily to identify power factor and harmonics issues but it's quite surprising how much under and overvoltage occurs on an installation.

The DNO will require a BS 50160 survey of at least 7-days duration before they will acknowledge any problem let alone propose a solution.

 

[Engineer54]

Tell me, do they use 230v or 240v in the BRB in max MCB Zs loop tables?? Personally when voltage is a factor in any calculations i need to do, i always use actual voltage, not virtual voltage. It can make a bit of a difference to your results too!!!