diversity

[dochisholm]

hi i have done a board change on a property for my assesment working out max demand with diversity is giving me a result of 152 amps due to there being 3 rings and 2 single sockets on seperate circuits really boosting the demand i know it will never pull this can someone suggest what to put in the maximum demand box and di i need to write anything in the comments box on the eic any help would be great thanks

 

[bugsy]

How have you calculated your M/D

 

[dochisholm]

apllied diversity from osg

 

[telectrix]

i add up the breaker ratings and divide by 2.

 

[dochisholm]

is that ok

 

[s_d]

surely the maximum demand is the rating of the main fuse?

 

[gpz900jim]

or take the value of the highest circuit and add it to the total of the rest of them after you have multiplied them by 0.4

 

[SimpleSimon]

Whats the one that Malcolm says, add up all the breakers and x 0.4 (Rule of thumb).

Dochisholm give use your calcualtions and break downs.

 

[dochisholm]

ok
cooker on 40 amp 10kw cooker
kitch skts 32
garagge 32
conservatory skts 32
wc skt 16
total lights 25 fittings advergage 100 watts each
down sockets 32
up skts 32
loft skt 20
immersion 2.8 kw 16 amp
boiler 16amp

p.s lights are on 4 circuits all 6 amps
cutout fuse is 60 thanks

 

[SimpleSimon]

Add all the breakers up = 292x 0.4= 117A. and remember not all will be on at the same time that will never amount to that figure quick enough to blow the fuse, check the time curve tables for a BS1361 Type II fuse in the regs and that'll take over a 1000 seconds to blow im guessing. By which time things would be started to switch off.

Your going to get alot of different answers on this one from different Sparky views, but personally I'd change that fuse to a 100A to be safe.

 

[i=p/u]

here here at least

 

[dochisholm]

hi am i allowed to change the fuse also its for assesment tommorow what would you suggest i document and say to look the bomb ha

 

[SimpleSimon]

No you can't as it's sealed and not your property. You will have to contact the DNO to upgrade.
What I would do is show your workings and your reasonings. Before the assessment if possible contact DNO, maybe they will give u a date to come and upgrade. Than at least you've got something to show them.
Good luck and let us know.

 

[dochisholm]

thanks simon

 

[tony mc]

If you have a clamp meter take a reading with everything switched on and you will be surprised.

Good luck with the assessement