maxium demand

[philipbbop]

can some one tell me how to work out maxium demand
i have 13 lighting points
2 ring circuits
8 sockets on kitchen ring and 13 sockets on the other ring
1 cooker
1 hob
1 immersion heater
1 heater

many thanks if some one can help also how do i work out maxium demand for a shower

 

[kevindgas]

sorry my crystal ball is at the cleaners

maximum demand depends on what you have and how you use each item
start with lights and add up all the bulbs 100w, 80w etc then take the total and divide the answer by the incoming voltage this will give you the Amp draw
do the same for each item you wish to plug in.
then add the cooker, shower, heating

add everything togther (and i bet it will be over a 100 amps!! )

 

[RMS]

add everything togther (and i bet it will be over a 100 amps!! )

Hence, the reason we apply diversity.

Calculating maximum demand for fixed load circuits is straight forward, however, ring final circuits can be problematic unless you have a good idea what will be used.

Diversity is then applied and is an allowance / estimation of the maximum demand as it is unlikely that all appliances / loads will be used at the same time.

If you provide us with the total load for each circuit then we can help.

 

[PrenticeBoyofDerry]

Very rarey are all circuits on full load for a period of time, so allowances for diversty are calculated

can some one tell me how to work out maxium demand
i have 13 lighting points 66% of load
2 ring circuits 1@ full load the rest @ 40%
8 sockets on kitchen ring and 13 sockets on the other ring all the other socket circuits @ 40%
1 cooker 10A +30% of full load of appliance in excess of 10A plus 5A for socket outlet if incorporated to isolator
1 hob as above
1 immersion heater full load
1 heater full load

many thanks if some one can help also how do i work out maxium demand for a shower

 

[ban-all-sheds]

can some one tell me how to work out maxium demand

Why do you need to know?

 

[ponyagent]

Very rarey are all circuits on full load for a period of time, so allowances for diversty are calculated

can some one tell me how to work out maxium demand
i have 13 lighting points 66% of load
2 ring circuits 1@ full load the rest @ 40%
8 sockets on kitchen ring and 13 sockets on the other ring all the other socket circuits @ 40%
1 cooker 10A +30% of full load of appliance in excess of 10A plus 5A for socket outlet if incorporated to isolator
1 hob as above
1 immersion heater full load
1 heater full load

many thanks if some one can help also how do i work out maxium demand for a shower

this is more for circuit design than actual max demand in terms of pull

 

[PrenticeBoyofDerry]

this is more for circuit design than actual max demand in terms of pull

You still make appropriate allowances for diversity.
If we wanted to calculate the maximum maximum demand, the simple method would be to add up all the current ratings of the load.

 

[vv2806]

Why do you need to know?

Suspicious as always

 

[ban-all-sheds]

Just taking care to establish the full context so that we can give properly informed advice.

 

[kevindgas]

add everything togther (and i bet it will be over a 100 amps!! )

Hence, the reason we apply diversity.

the question was how to work out maximum, whilst diversity can be applied that isn't the maximum load (which of course will be impossible to work out as we all change things constantly)
i have on the odd occassion needed to find out the cuase of MCB/RCD trips and it can be quite frightening what some people have on their ring mains

just in my own lounge i have a maximum draw of 55amps of which best part of 30amp is constant

kitchen has 2 microwaves, toaster, kettle, washing machine, tumble dryer, freezer, fridge and a sandwich toaster so thats 9 x 13A if everything is on at once (unlikely)

 

[ban-all-sheds]

just in my own lounge i have a maximum draw of 55amps of which best part of 30amp is constant

7kW of Class A amplification?

Or did you have RF do the lighting?

kitchen has 2 microwaves, toaster, kettle, washing machine, tumble dryer, freezer, fridge and a sandwich toaster so thats 9 x 13A if everything is on at once (unlikely)

It doesn't work like that.

 

[plugwash]

There are some diversity guidelines in the regs but they tend to overestimate by quite a bit. The fact is most houses are on 60-100A fuses and they almost never pop despite the "max demand according to diversity guidelines in the regs" being well over 100A.

Honestly on a domestic install it's not something to really worry about too much. Most high loads are pretty short duration so the chances of more than a couple being on at the same time for long enough to matter is pretty low.