Working out Diversity?

LukeScotty · Jan 8, 2008

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

TonyM58 · Jan 9, 2008

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 · Jan 9, 2008

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

TonyM58 · Jan 10, 2008

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