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From: Don Y <blockedofcourse@foo.invalid>
Newsgroups: sci.electronics.design
Subject: Re: British (european?) kitchen counter electric outlets
Date: Sun, 9 Jun 2024 18:19:45 -0700
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On 6/9/2024 3:38 PM, TTman wrote:
> On 08/06/2024 23:53, Don Y wrote:
>> In the US, we are required (new construction) to have two dedicated 20A
>> (2400W) circuits to service countertop "small appliances".  In addition,
>> there is also a requirement for a relatively tight spacing between
>> (duplex) receptacles -- the intent to keep cords short (IIRC, < 4ft...
>> we settled on 3').
>>
>> SWMBO was watching a britcom and commented at how few receptacles/outlets
>> were in evidence to serve the countertop.  Granted, each outlet is rated a
>> fair bit higher than US (each US outlet being 2400W -- the full load rating
>> of the branch circuit supporting it).  But, still, how do you address
>> NUMBERS of appliances in use, concurrently -- where each appliance will
>> likely draw only a fraction of the rated branch circuit's current so
>> total load isn't an issue?
>>
>> E.g., we (presently) have a ~1KW microwave oven and a ~1KW toaster as
>> ever-present loads.  To that, it is not uncommon to add an electric
>> wok, hand or stand mixer, pizzelle iron, etc.  The abundance of
>> outlets makes it easy to add appliances as well as providing flexibility
>> over where they can be put into use.
>
> We mostly fit double outlet sockets 20-30 cm above worktops on the wall. Each 

Jboxes tend to be about a foot above the counter -- /where a wall exists behind
the counter/.  (Outlets are required even in the absence of such a wall)

Here, we have 9 individual Jboxes to service the countertops:
- 5 1G boxes with 20A duplex receptacles
- 2 1G boxes with "communications" wiring
- 1 4G box to support a 20A duplex plus switches for garbage disposal, oversink
   lighting and overhead lighting
- 1 2G box to support 20A duplex plus a dual (half-height) switch to power
   the under cabinet lighting circuits

*Below* the level of the counter are the outlets for the stove/oven, garbage
disposal, dishwasher and refrigerator -- with the microwave oven off on
it's own.  These aren't intended to require normal access.

> socket ( there can be several spread around the kitchen area) can supply ( in 
> theory) 30 Amps @ 230V. Back at the main fusebox, there will be a 30 Amp MCB( 
> miniature contact breaker).

Here, a 20A circuit provides 2400W to the total load on that branch circuit
(though each receptacle can individually support a 20A load; loads exceeding
15A have a different plug configuration making them physically incompatible
with the normal 15A receptacles found in other rooms).

The branch circuit is protected in the load center with a 20A circuit
breaker (GFCIs in our case to eliminate the need to install GFCI receptacles
in the kitchen)

> All the sockets are wired in a 'ring main' format 
> to prevent excessive volt drops at any outlet.

Presumably, this means there is no "start" or "end" of the branch circuit?
So, no way to retrofit a GFCI receptacle to the "start" of the string and
provide that protection to the remainder of the string?

> A kettle will have a typical 
> power rating of 3kW so ~13 Amps draw. Other main appliances - dish 

The electric kettles I've looked at tend to be in the 1500W range
(I want to stop relying on the 3600W burner in the stovetop to
boil water; I'm willing to settle for longer boil times or
smaller boil volumes to do so)

> washer/washing machine/oven etc mostly have thier own separate supplies. Ovens 

Washer and dryer would typically be in some other "laundry" area
(with its own requirements).  Likewise for domestic water heater.
Big heat loads here are often powered with natural gas.  An
"all electric" house is seen as a bit of a curse though I've
a friend who has made such a switch.  (We rely on gas for heat
and domestic hot water, prefering electric for cooking)

[Two neighbors have such homes -- the gas supply was deliberately not
brought to their residences as part of some "development plan" (?).
Their electric bills tend to be ~$300/month, even in the low demand
(winter) months.  Adding gas to their homes would require excavating the
street and their front yards (actually, this could be done with a
drill but still costly!)]

> will be wired using 6mm cable.Microwave/toaster coffe maker will be plugged 
> itto a wall socket in the kitchen. Plugs will be fitted with either 3A/5A or 
> 13A fuses depending.

A problem with US wiring is that it relies heavily on protection devices
at the load center.  E.g., my pizzelle iron (750W?) is just a plug,
power cord and some nichrome wire.  The "power indicator" is actually
the glow of the nichrome wire as seen through a glass window!  :<

But, the adoption of AFCIs is intended to help address "failing" products
on the assumption that they will piss and spit AS they are failing.