Hi,

I'm looking at purchasing a homebrew boiler. It's basically a
stainless vessel with two integral 3kW heating elements.
The elements are capable of being switched independently
but there are times where I'd require both of them on. I intend
to use the boiler in my garage which has sockets served via
a RCD fusebox (don't know exact term for it) which is run as
a spur off the downstairs ring main. The downstairs ringmain
is connected to a 32A MCB, the house was constructed in
1990.

My question is, am I OK to operate the boiler with both 3kW
elements on given the above configuration ? I'd obviously
ensure that any additional load on the ringmain was minimised
by switching off TV, PC, washing machines etc. 6kW would
draw 25A - would my ringmain be OK with this ?

Cheers!

Andy.

Presumably your garage is on a 16A spur from the ring main?

The answer is no. Your peak power demand is around 25A and requires a
dedicated radial as well the appliance being wired in.

Can we ask what you're cooking up with a 6KW boiler?

wrote:
Presumably your garage is on a 16A spur from the ring main?

Not sure, will check at home this evening.....


The answer is no. Your peak power demand is around 25A and requires a
dedicated radial as well the appliance being wired in.

Darn.



Can we ask what you're cooking up with a 6KW boiler?

Beer!

My question is, am I OK to operate the boiler with both 3kW
elements on given the above configuration ?

Absolutely not. The load is completely unsuitable for your electrical
installation.

It isn't clear if your spur is fused or unfused. A fused spur can supply 13A
and an unfused spur is rated for 20A.

However, even if you ran only one of the elements, it still isn't allowed,
as immersion heaters are not allowed on socket circuits, as they are
inappropriate to the diversity calculations used to justify them.

Christian.

On Tue, 22 Aug 2006 14:18:48 +0100 someone who may be Owain
wrote this:-

In fact, you probably
have an RCD fused connection unit, so the spur will be restricted to 13A
max. (having the fused connection unit is the only way you'd be allowed
to have more than one single or twin socket on the spur).

Fuse of up to 13A or a circuit breaker of up to 20A.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 22 Aug 2006 05:54:53 -0700 someone who may be "Andy"
wrote this:-

I'm looking at purchasing a homebrew boiler. It's basically a
stainless vessel with two integral 3kW heating elements.
The elements are capable of being switched independently
but there are times where I'd require both of them on.

Quite a big boiler by the sound of it. Sounds like it is not
portable equipment and thus should be connected permanently to the
supply.

You will need a proper sub-main from your consumer unit to say a
four way board in the garage. From there you can run circuits to the
boiler, sockets, lights and so on.

The boiler should have a switch nearby. If it is vaguely portable
you might consider fitting a 32A BS4343 plug to the lead, which can
be plugged into a suitable socket.

Of you are in England or Wales beware of Mr Prescott.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On 22 Aug 2006 05:54:53 -0700 someone who may be "Andy"
wrote this:-

I'm looking at purchasing a homebrew boiler. It's basically a
stainless vessel with two integral 3kW heating elements.
The elements are capable of being switched independently
but there are times where I'd require both of them on.

Quite a big boiler by the sound of it. Sounds like it is not
portable equipment and thus should be connected permanently to the
supply.


No, it's very portable.

You will need a proper sub-main from your consumer unit to say a
four way board in the garage. From there you can run circuits to the
boiler, sockets, lights and so on.

The boiler should have a switch nearby. If it is vaguely portable
you might consider fitting a 32A BS4343 plug to the lead, which can
be plugged into a suitable socket.

Sounds like waaay too much hassle so I won't bother with the purchase.

Thanks for all the advice chaps.

Owain wrote:
Plugging the appliance into 2 sockets simultaneously (even though
presumably the heaters are entirely electrically separate) also means
you do not have a single point of isolation for the appliance.

There are carpet cleaning machines that are plugged into two sockets. One
cable runs the 3kw water heater, the other runs the 2 x 1200 watt vac motors
and the 100watt solution pump.

I have been told these could be dangerous, because in commercial buildings
the single phase sockets could be taken from different phases of the 3 phase
supply, so plugging in two cables from one machine could lead to a potential
415v shock.

Is that right?


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

"The Medway Handyman" wrote in
message k...
Owain wrote:
Plugging the appliance into 2 sockets simultaneously (even though
presumably the heaters are entirely electrically separate) also
means
you do not have a single point of isolation for the appliance.

There are carpet cleaning machines that are plugged into two
sockets. One
cable runs the 3kw water heater, the other runs the 2 x 1200 watt
vac motors
and the 100watt solution pump.

I have been told these could be dangerous, because in commercial
buildings
the single phase sockets could be taken from different phases of the
3 phase
supply, so plugging in two cables from one machine could lead to a
potential
415v shock.

Is that right?


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257



Potentially G

AWEM

Andy wrote:
David Hansen wrote:
On 22 Aug 2006 05:54:53 -0700 someone who may be "Andy"
wrote this:-

I'm looking at purchasing a homebrew boiler. I

Sounds like waaay too much hassle so I won't bother with the purchase.

Thanks for all the advice chaps.

What a bunch of spoil-sports -- there was a great chance for us all
to get free beer, and you all blow it out of the water !!

Rob

Andy wrote:
David Hansen wrote:
On 22 Aug 2006 05:54:53 -0700 someone who may be "Andy"
wrote this:-

I'm looking at purchasing a homebrew boiler. It's basically a
stainless vessel with two integral 3kW heating elements.
The elements are capable of being switched independently
but there are times where I'd require both of them on.

Quite a big boiler by the sound of it. Sounds like it is not
portable equipment and thus should be connected permanently to the
supply.


No, it's very portable.

You will need a proper sub-main from your consumer unit to say a
four way board in the garage. From there you can run circuits to the
boiler, sockets, lights and so on.

The boiler should have a switch nearby. If it is vaguely portable
you might consider fitting a 32A BS4343 plug to the lead, which can
be plugged into a suitable socket.

Sounds like waaay too much hassle so I won't bother with the purchase.

Thanks for all the advice chaps.

there are ways it can be run in the house off 2 sockets, each one on a
separate ring, but... the house just isnt set up for this kind of load.


NT

In article ,
"The Medway Handyman" writes:
There are carpet cleaning machines that are plugged into two sockets. One
cable runs the 3kw water heater, the other runs the 2 x 1200 watt vac motors
and the 100watt solution pump.

I have been told these could be dangerous, because in commercial buildings
the single phase sockets could be taken from different phases of the 3 phase
supply, so plugging in two cables from one machine could lead to a potential
415v shock.

Is that right?

One would presume such an appliance is designed with this in mind.
Shocks are usually to earth anyway, so it's very difficult to
imagine how such an appliance could give you a 415v shock in any
kind of even remotely possible scenario.

--
Andrew Gabriel

The message
from "The Medway Handyman" contains
these words:

I have been told these could be dangerous, because in commercial buildings
the single phase sockets could be taken from different phases of the 3
phase
supply, so plugging in two cables from one machine could lead to a
potential
415v shock.

Is that right?

As far as I know you shouldn't have nearby areas of the same building
running off different phases.

--
Skipweasel
Pay no attention to that man behind the curtain.

On 22 Aug 2006 21:02:06 GMT, (Andrew
Gabriel) wrote:

In article ,
"The Medway Handyman" writes:
There are carpet cleaning machines that are plugged into two sockets. One
cable runs the 3kw water heater, the other runs the 2 x 1200 watt vac motors
and the 100watt solution pump.

I have been told these could be dangerous, because in commercial buildings
the single phase sockets could be taken from different phases of the 3 phase
supply, so plugging in two cables from one machine could lead to a potential
415v shock.

Is that right?

One would presume such an appliance is designed with this in mind.
Shocks are usually to earth anyway, so it's very difficult to
imagine how such an appliance could give you a 415v shock in any
kind of even remotely possible scenario.

I remember an electric water still in one of the chemistry labs at
school. It was made by a firm called Manesty and it had two mains
plugs. I don't know whether or not the two sockets were on different
phases; I assumed that the arrangement was merely to accomodate a
current draw in excess of 13A. I'd have thought that since the sockets
were clearly provided for the still that they'd be on separate radial
circuits.
No doubt it'll have been removed by now - distilled water is probably
banned now under COSHH regulations ;-)
I know that pupils used to be rebuked by "Jakey" for squirting
distilled water at one another - "It costs a shilling a pint, boy!"

--
Frank Erskine
Sunderland

There are carpet cleaning machines that are plugged into two sockets.

Do you know any brand names?

Is it possible this was a "modification"?

I'd expect such a specialised machine to plug into an industrial 3
phase connector.

In article om,
" writes:
There are carpet cleaning machines that are plugged into two sockets.

Do you know any brand names?

Is it possible this was a "modification"?

I'd expect such a specialised machine to plug into an industrial 3
phase connector.

.... which would make it useless nearly everywhere.

--
Andrew Gabriel

wrote:
There are carpet cleaning machines that are plugged into two sockets.

Do you know any brand names?

Hydromist, now Truevox. And a few others.

Is it possible this was a "modification"?

No, off the shelf jobby

I'd expect such a specialised machine to plug into an industrial 3
phase connector.

Virtually all cleaning machines are designed to plug into a 13 amp socket.
At least 99%.


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

The message om
from " contains these words:

There are carpet cleaning machines that are plugged into two sockets.

Do you know any brand names?

Is it possible this was a "modification"?

I have a friend who has a welder with two 13A plugs on it 'cos it keeps
blowing the fuse if he only uses one.

--
Skipweasel
Pay no attention to that man behind the curtain.