LukeScotty

hiya, since being taught diversity on the course I went on, i've lost all memory of finding out diversity, so I was wondering if someone could give me the fomula to work it out and where to look in the regs, maybe a few examples. I needed to use it today on a job, but had no chance, I have to learn it! its essentially for the 2391 exam isnt it + all the jobs ya do?? cheers tonym58 in advanced if you get time to answer this for us and anyone else who gets in before him

regards Luke

If You Build It, They Will Come n If it aint broken don't fix it!

TonyM58

Luke

easiest is go to OSG Appendix 1 P84 (off the top of my head-i been doing this job too long!)

Table 1A and 1B are good.

There is no set formulae, it depends which circuit you are on

i always use a cooker as a good practice.

Calculate by:

first 10A of rated current
Plus 30% of remainder
Plus 5A if socket outlet incorporated in cooker control unit

So take a 10Kw cooker with s/o in CCU (purely for example)

current I = P/V = 10000/230 = 43.4A

Take first 10A leaves 33.4A

30% of 33.4 = 10.02

Plus 5A for s/o

So: first 10A, plus 10.02A plus 5A = 25A

This would then be used as your Ib for your IbInIz calculations

Each circuit is different:

Instantaneous water heaters (showers)

100% fl of largest
+100% fl of second largest
+ 25% fl of remaining

What do you mean you havent got three showers!!

Ok, hope this has helped
give me a shout if you want any more, no problems

LukeScotty

Righty, gonna have a go with a heater and x 3 (4.5kW Outdoor Heater)


Calculate by:
100% of total current demand up to 10 amperes +50% of any current demand in excess of 10 amperes

1 x 4.5kw = 4500

current i = p / v = 4500/230 = 19.56A

10amps + (50% 9.56) = 14.78A
------------------------------------------------------------------------------------------

Calculate by:
100% of total current demand up to 10 amperes +50% of any current demand in excess of 10 amperes

3 x 4500 = 13500

current i = p / v = 13500/230 = 58.69A

because its over 10A i find 50% on the remaining 58.69A - 10A = 48.69A

50% of 48.69 = 24.34A

10A + 24.34A = 34.34A


am I on the right lines??????


regards Luke

If You Build It, They Will Come n If it aint broken don't fix it!

TonyM58

Luke,

assuming its domestic then yes, damn right dude!

once you done a few they become second nature

and tommorrows lesson will be......?!

regards

Tony

LukeScotty

hehe, i'll think about that when i'm driving to a job tomorrow, or maybe something I come across when am there cheers tony

If You Build It, They Will Come n If it aint broken don't fix it!