Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 12 replies
  • Subscribers 32 subscribers
  • Views 1708 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

DNO upgrade.

broadgage
A farm near me has only a single phase 60 amp supply, believed to be 100 amps until the fuse operated recently. They are the last customer on an LV overhead line and the voltage regulation is very poor.

A three phase 11Kv line crosses their property, but the supply is not derived therefrom rather surprisingly.


They have requested an upgrade to three phase 200 amps.


The DNO have offered this for some very substantial price, but have offered to waive this fee if the farmer will grant to the DNO a long lease for a small substation. Consisting of a ground mounted transformer, air break 11 Kv switches atop poles and related equipment, room for second transformer if required.

This seems to me to be a good bargain, is there any reason not to agree ?
  • 0
    As you describe it, I suggest he bites their hand off quick.. ?

    Unless - the proposed new transformer is so large or in such a place that will obstruct access to,  or the normal working of, the farm, or they need to do a lot of excavation for earth mats and so on to install it.

     

    I presume they are thinking of reversing the direction of the LV and supporting the supply to  other users at the low end of the current cable - space for two transformers sounds like they are thinking of more than just this farm.

    Is the proposed new farm supply TT or TNS - you do not really want questions of step voltages from electrodes - is this the sort of farm with priceless horses, or herds of valuable cattle, or more like a grain dryer and shed full of chickens ? It may matter a bit. Check if for example once the new TX is in , how close the DNO think he can plant an electric fence to it.

    Mike.

  • 0
    The proposed substation site is in a corner of a triangular field, about 50 m from the farm house. Considerable excavation is proposed, presumably for earthing.

    Not known if the new supply is to be PME or proper earthing.


    Horse livery is a significant part of the business, but the stables are remote from the proposed substation site and are already a TT island.


    Free range beef cattle are the main business, presumably grazing up to the boundary fence is low risk. 

  • Former Community Member
    0 Former Community Member
    As above, snatch their hand off! They quoted around £30k?


    If ground mounted, 500 kVA upwards as pole mount is 315 kVA maximum.


    Not sure of their reasons for the facility to supply 500 kVA at 400 V though.


    Regards


    BOD
  • 0
    I feel sure that, let's say, 100 m² of farm land against the cost of the new supply is a bargain; but why upgrade from 60 A to 600 A?
  • 0
    perspicacious:

    Not sure of their reasons for the facility to supply 500 kVA at 400 V though.


    Makes me think of a small housing development.


  • 0
    Chris Pearson:

    I feel sure that, let's say, 100 m² of farm land against the cost of the new supply is a bargain; but why upgrade from 60 A to 600 A?




    Future proofing is the main reason, future uses may include dairy farming with on-site processing of milk into butter and cheese, or perhaps fruit and vegetable cultivation for supermarkets, considerable power is needed for washing, sorting, packaging, and cold storage.

    Possible future electric heating and EV charging.

    Maybe grid tied PV in excess of the usual 16 amps per phase.


  • 0
    I was thinking is it for a water or sewage pumping station? Maybe that plus the farm and some village houses mite add up to 500 Kva  or possibly someone's building a big supermarket  near by. Whatever the reason I agree bite there hands off  getting all that for free bargain or what
  • Former Community Member
    0 Former Community Member
    Future proofing is the main reason, future uses may include dairy farming with on-site processing of milk into butter and cheese, or perhaps fruit and vegetable cultivation for supermarkets, considerable power is needed for washing, sorting, packaging, and cold storage.

    Possible future electric heating and EV charging.


    If all that is implemented, I would have thought they would need an ASC (Authorised Supply Capacity) in excess of 138 kVA.


    Regards


    BOD
  • 0
    Chris Pearson:
    perspicacious:

    Not sure of their reasons for the facility to supply 500 kVA at 400 V though.


    Makes me think of a small housing development.




    Indeed, planning permission for any significant new build is unlikely, but the farm next door includes several old and at present unused cottages, these are to be renovated and used for farm staff. Possibly as much as 100KVA. The next door farm also has PP for a single but large dwelling . Perhaps another 72 KVA .

    And as has been suggested, I presume that the existing overhead LV line is to be fed from both ends.


  • Former Community Member
    0 Former Community Member
    but have offered to waive this fee if the farmer will grant to the DNO a long lease for a small substation. Consisting of a ground mounted transformer, air break 11 Kv switches atop poles and related equipment, room for second transformer if required.


    Your 138 kVA would be easily supplied from a PMT (Pole Mount Transformer) so I still wonder why the DNO want the facility to supply 500 kVA and possibly the same again for a load that your client isn't asking for.............


    Regards


    BOD

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines