Gas removed for New Electric all over flat

[sl1210]

Hi guys,

Could do with some advice on a job I've got on this week.

A lady from holland who has a flat in a block of flats in London has had her gas supply totally removed from her flat, as she is dead against it. Now the problem is she only has a 60a fuse at the rifle board supplying her flat. A guy from EON came today to supposedly upgrade the main fuse to 100a and tails etc. But due to some miscommunication he thought he was only coming to remove the 60a fuse to kill power to the flat. Now when he came he said it wouldn't be easy to upgrade the rifle board fuse, as the service head only had 3x100a. And that to upgrade these would mean cutting off power to the whole block, and upgrading the mains from the road.

This is the new load

1 x 3kw? water heater
2 x 2kw heaters
1 x 1.5kw heater
1 x 1kw heater
1 x 1.9kw steamer
1 x 3.6kw cooker
1 x 3.2kw hob
1 x 2.2kw dishwasher

+ washing machine, dryer, towel rail

Now all this at full load would definitely use over 60a. Anyway the lady was advised by someone to order a wylex fuseboard with an inbuilt Wylex MESB-63NO 63a Contactor. She also had a dutch kitchen fitter bring over all the new items from holland.
I've never fitted one of these contactor's before and was wandering what would be the best way to arrange the circuits and how to wire in this contractor??? And would it be possible without upgrading the main fuse??

Cheers

 

[Outspoken]

Please explain why she needs a contactor in her DB? Is this some kind of snake oil someone has been filling her head with because that part # you gave is a standard 3 module 4 pole contactor that would be used to switch loads on and off en masse so to speak. The isolator on a domestic DB will achieve the same, if you or her are that worried about overloading the supply then feed the out going ways via a 63A DP MCB after the Isolator, or get a board with no isolator and just use a 63A DP MCB...

However i would suggest you look at reducing the load on the supply and this can be achieved simply, for heating, you could cut the load down by having a conventional wet heating system installed with radiators etc, but instead of a boiler you have an immersion heater in a tank. The circulation is then done via a standard heating pump. Primary hot water would be done at the same time if you use an indirect tank.

 

[sl1210]

the board came pre-loaded with mcb's and does include a 63a mcb (i'm guessing to supply the contractor??)

she has removed all gas supply in the flat and that includes all the previous water radiators, she doesn't want gas in the property.

plus she has these electric heaters already on site

 

[Outspoken]

Are you actually an Electrician?

 

[Guest55]

she doesnt need a bigger supply or contactor.
if her flat uses more than 50A continuous then im the emperor of china.
;-)

 

[Outspoken]

Biff, can I order a take out then please...

 

[sl1210]

yes i am an electrician, just never had a job like this before.

i'm confused though. i know the chances of everything being on at the same time are very rare but if she was to use all the above items i listd then without any diversity i calculate that at 88amps

 

[Outspoken]

​diversity

 

[sl1210]

so at the moment i have a 32a ring which will supply on 13a fcu's the steamer, washing machine, dryer, dishwasher, fridge and freezer.
the 3.2kw hob has its own 16a radial supply
the 3.6 hob will have its own 16a radial supply
the 3kw water heater will have its own 20a radial supply

just not sure how to feed the 4 x heaters and towel rail. as that ring is very loaded. was thinking of running a dedicated supply for the 2x 2kw ones, and just spur off the ring for the 1.5kw and 1kw.

what do you think???

 

[KAS1]

This is only a flat isn't it, now what's the problem again ?

 

[snowhead]

so at the moment i have a 32a ring which will supply on 13a fcu's the steamer, washing machine, dryer, dishwasher, fridge and freezer.

You seem to have applied diversitiy to that lot, any 2 of those could take out a 32amp MCB.

Now what's the problem again ?

 

[Guest55]

if it was me ........

4mm radial / 32a for kitchen appliances
2.5mm ring / 32a for sockets

the other fixed loads the same as your discription ,

then for the heaters 3 x 2.5mm radials , one for each of the 2kw , one for both the 1kw + 1.5kw.
spur off ring for towel rail , there only a few amps.

 

[Knobhead]

I'd just add a pinch of salt to the lot!

 

[GLENNSPARK]

​diversity

the instantanious water heater: no diversity....
as for the rest...

 

[Outspoken]

the instantanious water heater: no diversity....
as for the rest...

Clearly...but he was taking into account at all when it needed to be accounted for..

 

[SPARTYKUS]

Sl1210

the only reason I can think you may need a contactor ( not contractor!) would be if you wished to switch all heaters on or off together, from one point, with one switch.

this switch, marked "heating" would engage the contactor that would in turn supply the heaters ( various mcbs and circuits as per Biffs comment).

 

[sl1210]

i'm not re-wiring the place just modifying a few things. its a pain because most of the flat is on 1 ring. i have used one of the existing radiala to feed the 2 plate hob. and run another radial to supply the cooker. i'm going to use the old 6mm cooker circuit to feed the boiler. the rest is pretty much on the ring.

i have a feeling the heaters may be switch on together as she showed me a thermostat and some sort of controller as i was leaving, so more then likely that is what the contactor is for.

 

[sl1210]

turns out the board that was supplied with the contactor and mcb's was solely just for the four heaters so they can all be turned on via a digital programmer and a thermostat so each heater will need a radial run to it via a switch spur from the 16a mcb's at the board.