Voltage drop off on 200m cable.

[KennyFraser]

Hi there

I have a 200 metre underground cable between 2 farm sheds that is experiencing a fair voltage drop. 

Is there any way of reversing the drop off or boosting it back up. Struggling to use some of the bigger draw electric tools and machines. 

Have been told this is not reversable but I have seen American systems where the appear to use boosters to to boost the voltage back up again. Think they were called buck boost transformers or something like that. Surely there must be a way of boosting or reversing the voltage drop. 

Hopefully someone can advise me on this. 

Many thanks 

Kenny

 

[SPECIAL LOCATION]

Basic laws of physics... 

You cannot get more power out of a system than the power put in..

in  electrical terms Power (watts) = Voltage (Volts) x Current (Amps)

So whilst it is possible to use a transformer to decrease / increase the voltage..

the current will also proportionally change as you cannot generate more power out of thin air!

I would guess the correct solution to your problem would be to install appropriate cable size to ensure the Volt-drop remains within the specifications of BS7671.

Who installed the cables?

What power calculations did they do prior selecting the cable size?

or is this just a DIY bodge.. see if it works then find is doesn't?

:C

 

[kerching]

Well if it's like my mates farm..... 180m 2.5 T&E run underground in a hosepipe. Joint is in a Crawford Biscuit tin

this is the guy that tried to save me time by installing a cable in the concrete for a table saw (3 phase)....50pr BT cable!!  "well it was black and about the right diameter, same as 3 phase cable". Apparently 3 phase cable is a 'dimension' ! Who knew!

 

[Murdoch]

Ouch - 200 meters of cable.

You need to determine the load of the appliances in the buildings before anything else

No solution is going to be cheap.............

Do you have any buildings closer to the supply you could move the appliances to?

 

[Andy™]

guessing someone looked at 2.5 can carry 20a so should be fine at 200m?

 

[Sidney]

Without knowing the load, number of phases, etc then impossible to advise from here.

I'm guessing there's also lighting involved which makes things a little more difficult. For any sort of decent load requirements you'd be looking around the 50mm CSA area for a supply cable.

 

[Bruspark]

Without knowing the load, number of phases, etc then impossible to advise from here.

I'm guessing there's also lighting involved which makes things a little more difficult. For any sort of decent load requirements you'd be looking around the 50mm CSA area for a supply cable.

It’s a twist on a bodge but if the heavier equipment at the far end can survive on the too low voltage (a big if!) a separate lighting cable run alongside won’t suffer much drop If using LEDs etc.  
 

Ideally add a proper much larger cable for the power feed and use the one you already have for lighting (assuming it’s suitable) 

 

[tomsw18]

I wonder if there is some kind of auto-transformer or step-up transformer that could regulate the voltage for you. I can't see it being a cheap solution but something might exist?

The main issue I foresee would be switching of loads fluctuating the voltage. Might be worth looking into though.

 

[Evans Electric]

Well if it's like my mates farm..... 180m 2.5 T&E run underground in a hosepipe. Joint is in a Crawford Biscuit tin

How dodgy is that  !!!!       Everyone knows you'd use a McVitie's   tin for underground joints .      :C   No wonder this trade is going down . 

Crawfords  ...dear oh dear !!!

 

[kerching]

How dodgy is that  !!!!       Everyone knows you'd use a McVitie's   tin for underground joints .      :C   No wonder this trade is going down . 

Crawfords  ...dear oh dear !!!

He's a lovely bloke.....just that he is thicker than mince