IET
Decrease font size
Increase font size
Topic Title: 415v 3 phase supply or 400v 3 phase supply in private premises
Topic Summary:
Created On: 15 May 2012 08:21 AM
Status: Read Only
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 15 May 2012 08:21 AM
User is offline View Users Profile Print this message



martinj78

Posts: 38
Joined: 19 May 2011

If I use 415v three phase LV distribution within my premises i can reduce the current and save from main feeders. Power incoming is MV and premises will have dedicated step down transformer.
 15 May 2012 09:25 AM
User is offline View Users Profile Print this message



broadgage

Posts: 3170
Joined: 07 August 2007

Although the nominal UK voltage was reduced some years ago from 240/415 down to 230/400, the actual voltage supplied from either DNO or private transformers tended to remain at about 240/415 average at the load, and often 250/433 at the transformer.

In the case of a privately owned transformer you can of course select a lower voltage such as 230/400.
This is unlikely to save energy* in most cases, and may result in an unduly low voltage at farthest point of use if the premises are extensive with long submains and subcircuits.

In the case of extensive premises or estates of detached buildings with long cable runs then I would select the highest reasonable voltage at the transformer, probably 250/433 so as to allow an ample margin for voltage drop.

In the case of more compact premises I would be inclined to select 240/415 at the transformer thereby giving a more modest allowance for voltage drop within the premises.

I would not go as low as 230/400 at the transformer unless in the exceptional case of a transformer very close to the load.

*A search of these forums will reveal many threads on alleged energy saving by voltage reduction. The consenus view, and my personal view is that no saving results in most cases.
 15 May 2012 03:35 PM
User is offline View Users Profile Print this message



ToniSM

Posts: 465
Joined: 21 November 2006

You say the transformer is dedicated to your works. Is it yours or the DNO's? does it have an off load tap changer? Most DNO transformers don't.

If it does then you can lower the voltage. BUT the supply must be OFF so the DNO will have to be involved.

As has been said it could cause more problems than it's worth.

Tap Based on 11000V incoming
V 440 433 415 400 380
%
-5 418 411.35 394.25 380 361
-2.5 429 422.175 404.625 390 370.5
0 440 433 415 400 380
2.5 451 443.825 425.375 410 389.5
5 462 454.65 435.75 420 399

-------------------------
The reports of my death are greatly exaggerated.
 15 May 2012 03:36 PM
User is offline View Users Profile Print this message



ToniSM

Posts: 465
Joined: 21 November 2006

OK how do you insert a table?

-------------------------
The reports of my death are greatly exaggerated.
 15 May 2012 03:59 PM
User is offline View Users Profile Print this message



AJJewsbury

Posts: 17795
Joined: 13 August 2003

OK how do you insert a table?

...with difficulty!

One option is to draw it in a document, post it one one of the file/photo sharing sites and then post a link to that here (once you've become established enough to be allowed to post links).

The forum software looks like it's capable of allowing "WYSIWYG Editing" ( http://forums.fusetalk.com/att...attachid=253&forumid=1 (page 11) ) but that doesn't seem to have been enabled for us

- Andy.
Statistics

New here?

  • To participate in discussions, please log in and introduce yourself.

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2022 FuseTalk Inc. All rights reserved.

 
..