Volt drop for entire installations

[Monkeyblaine]

Richard one last thing. When designing a sub main do you work out volt drop to a 3 or 5% volt drop.

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Richard one last thing. When designing a sub main do you work out volt drop to a 3 or 5% volt drop.

 

[Guest55]

does anybody bother to thank Tony for his informative diagrams these days ?

this place has become chock full of ungrateful ****ers these days.

 

[Silly Sausage]

does anybody bother to thank Tony for his informative diagrams these days ?

No, because he only comes over here to take the proverbial!

 

[ackbarthestar]

As a rule of thumb, assume 230V at the origin and allow 3% to the furthest outlet for lights and 5% volt drop for all power circuits.

It's bonkers in real life because if you have a dedicated supply you will have, as so many people have stated, 433V open circuit voltage with a progressive volt drop appearing at each DB.
Most large installations will have a starting voltage of anywhere, single phase, between 240V to 250V, but you cant use these figures unless you are the designer of the system and you have made allowances for loading and future expansion.

 

[Outspoken]

This shows the cumulative effect of volt drop

Tony, what size cables did you use and what type was it as that impacts the volt drop...Muhahahahaha

(Sorry, someone had to say it)

 

[ackbarthestar]

Tony, what size cables did you use and what type was it as that impacts the volt drop...Muhahahahaha

(Sorry, someone had to say it)

Can't you work that one out for yourself ?

Just place a thank you for helping you to be reminded ..............

What was that?..... 'Get stuffed !' ?

It's ok , I'll do the jokes .....

 

[Guest55]

It's ok , I'll do the jokes .....

good grief , i'll get yer coat......

"taxi for ackbar"

;-)

 

[ackbarthestar]

good grief , i'll get yer coat......

"taxi for ackbar"

;-)

**** ** Nice pick up line.... where are we going ?

 

[Guest55]

dunno , ask the driver.
lol.

 

[ackbarthestar]

Too much smoke emanating from the driver's cabin... he keeps sayin ---'Yea man'
I've got no idea either....
Have you got any pop corn ?....It could be a serial ......

 

[Monkeyblaine]

Ok then with my over analysing mind I have another question. If you take a light feed to a switch and say for argument sake you lose 1v across it. Then you take two from that feed and take them equal distances with equal loads. Do you add the volt drop for every cable? Because Surely if you say on the left cable you lose 2 v to the light then your left with 230 - original 1v to switch then - 2v to light your left with 227v at left hand light. Much the same as the right hand cable being the same length you again lose 1v to the switch then - 2v again to to right hand light again leaving 227volt at light! So in this instance (hyperthetically of course) do you just take calculation for one of the two outgoing feeds from switch?? As they will both have 227 at them??

 

[ackbarthestar]

I sse where you're coming from Hypotheticaly speaking, of course.......Lol, depends on the length, size of conductor and loading, then you might want to consider diversity.
If the lights are on continuously you will have a volt drop equal to the loading at each point, not the total. However, if the load was centered at one point then you would take the volt drop using the total load.
In your example we are likely to have a short run with a high load and switched to a long run with a light load.

 

[Monkeyblaine]

Oh of course. I completely understand. I have serious over analysing problems. But it's nice to see I was on the right lines. Equal load, equal split VD and if load is centred then you take VD of total. I Spose if you wired it like this you could make an argument for a larger allowance of VD for said lighting circuit. Double in fact. Hyperthetically of course. Hahaha. Thanks again for putting my mind at rest.