# maximum demand and diversity

Discuss maximum demand and diversity in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

H

#### hossamozi

Welcome to ElectriciansForums.net - The American Electrical Advice Forum

I Have a question?
I want understand How can i apply the diversity factors and calculate the maximum demand on
1-one flat to get the feeder
2-set of flats to get riser
3-set of building to get transformer

(if there is an example please attach it )

for lighting 66% but on the MCB rating or on the actual current
and the microwave ,washing machine,and dishwasher we put it on normal socket or on power socket and what the diveristy applied in normal socket ,normal socket circuit

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G

#### Guest123

Hey.

Ok, diversity is as follows:

Lighting - 66% of total current demand for each circuit
Power - 100% of the first ring circuit + 40% of all other circuits
Cooker - 10A + 30% of remaing rated current + 5% if the CCU has a socket outlet
Shower - No diversity allowable
Instantaneous water heater - 100% of largest heater + 100% of second largest + 25% of of any others
Thermostatically controlled water heater - No diversity allowable
Underfloor heating - No diversity allowable

I think thats about it. Obviously you would do this for each flat and this will give you a rough building total to work out feeder sizes/protective device ratings etc.

Hope this helps.

H

#### hossamozi

thank you very match

Hey.

Ok, diversity is as follows:

Lighting - 66% of total current demand for each circuit
Power - 100% of the first ring circuit + 40% of all other circuits
Cooker - 10A + 30% of remaing rated current + 5% if the CCU has a socket outlet
Shower - No diversity allowable
Instantaneous water heater - 100% of largest heater + 100% of second largest + 25% of of any others
Thermostatically controlled water heater - No diversity allowable
Underfloor heating - No diversity allowable

I think thats about it. Obviously you would do this for each flat and this will give you a rough building total to work out feeder sizes/protective device ratings etc.

Hope this helps.
thank you very match

to determine the design current of normal socket circuit we apply diversity( 100%largest socket +40%reminder) &what the number of socket on the circuit ?
for example
assume we use 10 socket\circuit and the rating of the socket 16A
so the design current of socket is 16A and the design current of the circuit 16+9*0.4*16=73.6 if this wrong please tell me the correct answer

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P

#### pushrod

Ignore the number of sockets on the rings.

H

#### hossamozi

Ignore the number of sockets on the rings.
THANKS
BUT i USE RADIAL NOT RING
IN RADIAL CAN I IGNORE THE NUMBER OF SOCKETS ?

P

#### pushrod

In terms of diversity - yes

H

#### hossamozi

in terms of diversity - yes
this mean that maximum demand of normal socket circuit is the circuit breaker rating

P

#### pushrod

this mean that maximum demand of normal socket circuit is the circuit breaker rating
That is what i understand it to be.

H

Thanks

P

#### pushrod

No problem, just hit the "thanks" button

#### DPG

##### -
Arms
Esteemed
Am I being silly here? Where does the 16A socket rating come from?

P

#### pushrod

Am I being silly here? Where does the 16A socket rating come from?
I think he probably meant the MCB rating for the radial circuit - but wasn't sure. Might have been a fixed load at a double socket as it sounded as if he was doing a theory question.

P

#### petegibbons

I am trying to calculate the maximum demand for a domestic property which has got 7 showers in it. Do I ad in each shower being used at 100%??

P

#### pushrod

7 showers wow! I would think that some discussion with the owner is appropriate to ascertain if there will be occasions when they all could be being used or if it will never happen.EG a bed and breakfast and you would have to just add them up.

P

#### petegibbons

7 showers wow! I would think that some discussion with the owner is appropriate to ascertain if there will be occasions when they all could be being used or if it will never happen.EG a bed and breakfast and you would have to just add them up.
It's a supported housing property, they will never be on all the time.

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