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 Topic Title: Maxmum demand Topic Summary: Calculating Created On: 19 January 2013 11:30 AM Status: Read Only Linear : Threading : Single : Branch
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 19 January 2013 11:30 AM Nedd Posts: 9 Joined: 18 February 2012 Hi all I was told by a lecturer an acceptable method of calculating maximum demand as required on EIC. I think it was, add all fuses or mcbs at the db together then divide the total by 40 the remainder is the demand is this right or not. If not which is the best way to calculate the load Thank you . 19 January 2013 12:35 PM rocknroll Posts: 9550 Joined: 03 October 2005 Not quite, the demand factor is less than 1, the diversity factor is greater than 1, the most common method used by the DNO's for estimating the demand was multiply by the factor 0.4. regards ------------------------- "Take nothing but a picture,leave nothing but footprints!"-------------------------"Oh! The drama of it all."-------------------------"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"------------------------- 19 January 2013 02:22 PM kj scott Posts: 2144 Joined: 02 April 2006 Maximum demand will vary for different types of installation, and should be based on experience. A factor of 0.4 is not suitable for the consumers installations, even if it was appropriate for the distributor. There is some guidance in the IET publications, GN1 and the On site guide, but prior knowledge is the key to economic assessment. 19 January 2013 03:28 PM rocknroll Posts: 9550 Joined: 03 October 2005 You will find the estimation method for maximum demand of an installation in your IET Electrical Installation Design Guide with the appropriate IEC curve, fairly basic stuff really and perhaps show it to your lecturer. regards ------------------------- "Take nothing but a picture,leave nothing but footprints!"-------------------------"Oh! The drama of it all."-------------------------"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"------------------------- 19 January 2013 05:57 PM ebee Posts: 6347 Joined: 02 December 2004 I disagree about adding all the fuses together for a start. Just for example. Two exactly equal installations with exactly equal usage at all times. One has 10 circuits total. The other has 20 circuits total (half as many points on each circuit). The Max demand should be the same. OK potentially the one with twice as many circuits might be capable of becoming twice as overloaded at any time but the maximum demands should be similar. ------------------------- Regards, Ebee (M I S P N)Knotted cables cause Lumpy Lektrik 19 January 2013 06:37 PM Nedd Posts: 9 Joined: 18 February 2012 Originally posted by: rocknroll You will find the estimation method for maximum demand of an installation in your IET Electrical Installation Design Guide with the appropriate IEC curve, fairly basic stuff really and perhaps show it to your lecturer. regards Just found an earlier post of yours back in 2010 on the same subject A good in-depth post, told me all I wanted to know and more. Thanks 20 January 2013 10:41 PM Westonelectrical Posts: 85 Joined: 26 November 2012 VxI divide by 1000 done..
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