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 33 replies
  • Subscribers 32 subscribers
  • Views 3067 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

Very long run of LV Cabling

fiftyhertz

Hi all,

 

im looking at a project where the landlords LV cut out is approx 850 metres from the proposed tenants installation. The earthing arrangement is TT and protected by a time delayed 300ma RCD and a 63A MCCB.

 

The landlords sub main is going to be 2 x 4C 95mm2 in parallel buried in the ground to supply 20KVA worth of power. This achieved a volt drop of 1.6% which leaves 1.9% VD for lighting. From my Amtech calcs I also get about 1ka at the load Dis board (Phase fault)

 

im not worried about Earth Loop because of the RCD, but i am thinking about the adibatic of the phase conductors. If the tenant puts a long run of cabling in, this will comply from a Zs perspective, but could there be issues with the line under a phase to neutral /phase to phase fault as the cable could slowly cook under a lowish load without tripping the breaker. Is this a valid concern? Amtech isn’t throwing up any faults, but just wanted your thoughts.

 

thanks in advance

  • 0

    LPG is arguably cleaner and safer than petrol for small portable generators. At present however LPG is in very short supply. And a lot more expensive than price capped domestic electricity.

    Portable LPG cylinders are only available to existing customers that have empties to return, in most cases.

  • 0

    Click on the above.

     

    Z.

  • 0

    The trouble here is the regulatory environment. Many jobs now need Euro 6 Generators that are expensive and less efficient, and now they want to change to petrol or LPG, both of which are less efficient and more expensive, and much more dangerous, and getting a 500 kVA supply from LPG needs a big tanker on-site, it doesn't run from a normal dip cylinder at all. Probably about 300 litres per hour of LPG. The cost is only partly the fuel, it is the huge capital cost each time it changes. Charlie boy is so far from “Green” except in the head, that all this goes away with a wave of the hand, along with Doris and co.

    Please note my comment about oil refineries, changing the output fuel mix is incredibly expensive (billions) and guess who is going to pay, again!

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