Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.

On 18/11/16 12:02, Jack Lawson wrote:


Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.

check for earth neutral sorts.

In whatever its plugged into

Staring current on electric motors can be very high, and if some of that
isn't going back down the neutral...

--
"The great thing about Glasgow is that if there's a nuclear attack it'll
look exactly the same afterwards."

Billy Connolly

The Natural Philosopher wrote:
On 18/11/16 12:02, Jack Lawson wrote:


Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395


I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it
tripped
my RCD on the supply. Tested it further - sometimes it tripped -
sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will
trip.
The saw seems perfect for my needs - very accurate mitres and 90
degree cuts
are spot on - I think I will live with what for me is a minor problem
- but
thought I'd just share.

check for earth neutral sorts.

In whatever its plugged into

Staring current on electric motors can be very high, and if some of that
isn't going back down the neutral...

Test it with the earth disconnected and the saw on an insulating mat.

If is still trips then your RCD is a bit suspect.

DO NOT Run it like this. It is only a test method.

Jack Lawson wrote:


Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.


Is it definitely a RCD tripping and not just a MCB?

Tim

--
Please don't feed the trolls

In message , Tim+
writes
Jack Lawson wrote:


Earlier this week I bought from Homebase a mitre saw:

http://www.homebase.co.uk/en/homebas...-sliding-mitre
-saw-scms-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.


Is it definitely a RCD tripping and not just a MCB?

I have a 9" angle grinder which consistently trips a 20 amp MCB......

--
Tim Lamb

You could try it on a different circuit to see if it does the same, if it doesn't then there is a mains circuit fault.
I had an RCD trip only on heavy loads due to a neutral to earth fault elsewhere on the ring main. Hindsight and correct diagnosis would have saved me an afternoon f&%^ing about!

On 18/11/2016 16:17, Tim Lamb wrote:

I have a 9" angle grinder which consistently trips a 20 amp MCB......

You mean it trips a B type 20A MCB?

--
Adam

In message , ARW
writes
On 18/11/2016 16:17, Tim Lamb wrote:

I have a 9" angle grinder which consistently trips a 20 amp MCB......

You mean it trips a B type 20A MCB?

Yes. Fine elsewhere on re-wireables. Makita.

My workshop socket outlets are end fed so limited to 20 amps.


--
Tim Lamb

On 18/11/2016 20:43, Tim Lamb wrote:
In message , ARW
writes
On 18/11/2016 16:17, Tim Lamb wrote:

I have a 9" angle grinder which consistently trips a 20 amp MCB......

You mean it trips a B type 20A MCB?

Yes. Fine elsewhere on re-wireables. Makita.

My workshop socket outlets are end fed so limited to 20 amps.

My previous workshop initially had a 20A MCB protected socket circuit,
and things like my 3kVA site transformer would trip that on switch on
about one time in five. Its fine on a B32 or C20 though.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 18/11/2016 12:02, Jack Lawson wrote:


Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.

Is it even earthed, or is it double insulated?

The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.

This sounds more like a "sensitised RCD" nuisance trip as a result of
transients caused by the large inrush current. It probably only happens
when you manage to time the power on to coincide with the peak of the
mains waveform.

See http://wiki.diyfaq.org.uk/index.php/...nsitising_RCDs


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Some rcds seem to be a bit sensitive. I have a plug in one on the lawn mower
and its fine but the strimmer trips it for no obvious reason.
Not being sure quite how they detect things when you can get double
insulated, no earth and earthed things to plug in and its still supposed to
work.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Jack Lawson" wrote in message
...


Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it
tripped
my RCD on the supply. Tested it further - sometimes it tripped -
sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will
trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree
cuts
are spot on - I think I will live with what for me is a minor problem -
but
thought I'd just share.

On Fri, 18 Nov 2016 12:57:48 -0000 (UTC), Tim+ wrote:

Jack Lawson wrote:


Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.


Is it definitely a RCD tripping and not just a MCB?


Excellent - it is in fact a MK (ELECTRIC) 5916S Thermal Magnetic Circuit
Breaker, SENTRY Series, 240 VAC, 16 A, 1 Pole, DIN Rail

I now realise that there is just one RCD in the box - and it was in fact not
that which was tripping - I should have looked properly. It was the fact that
it tripped sometimes - not others - which confused me. The start-up current of
the motor must be round about the tripping current of the device - and nothing
to do with RCD nuisance tripping!!! (Since I made my post I had been reading
up about RCDs and have seen that they *can* trip when there is no earth-leakage
- known as nuisance tripping.)


Many thanks - problem solved.

Jack Lawson wrote:

Tim+ wrote:

Is it definitely a RCD tripping and not just a MCB?

it is in fact a MK (ELECTRIC) 5916S Thermal Magnetic Circuit
Breaker, SENTRY Series, 240 VAC, 16 A, 1 Pole, DIN Rail

Many thanks - problem solved.

Well, mystery solved but problem remains. What else is on the MCB that
trips? Is the circuit wired with 2.5mm^2 cable? It may be possible to
replace it with a 20A one, or a "type C" 16A one.

On Sat, 19 Nov 2016 02:49:57 +0000, John Rumm
wrote:

On 18/11/2016 12:02, Jack Lawson wrote:


Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.

Is it even earthed, or is it double insulated?

The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.

This sounds more like a "sensitised RCD" nuisance trip as a result of
transients caused by the large inrush current. It probably only happens
when you manage to time the power on to coincide with the peak of the
mains waveform.

See http://wiki.diyfaq.org.uk/index.php/...nsitising_RCDs


Yes - thanks - that is just what I had come to think it was as I read up after
making my post - and found about nuisance tripping.

However - as Tim+ questioned - was it the RCD? - and of course it wasn't.

I assume that I can put a larger MCB in - the cabling is a single spur from the
distribution box to the double socket in the garage - not on a ring.

What MCB would you suggest please?

Jack Lawson wrote:

What MCB would you suggest please?

If it's 2.5mm^2 cable you should be fine with a 20A type B (you already
have type B) but it's possible the saw might still trip it.

What's the total length of cable from CU to garage? Someone might do
the calcs to make sure a type C would be safe ...

On Sat, 19 Nov 2016 12:32:29 +0000, Andy Burns wrote:

Jack Lawson wrote:

Tim+ wrote:

Is it definitely a RCD tripping and not just a MCB?

it is in fact a MK (ELECTRIC) 5916S Thermal Magnetic Circuit
Breaker, SENTRY Series, 240 VAC, 16 A, 1 Pole, DIN Rail

Many thanks - problem solved.

Well, mystery solved but problem remains. What else is on the MCB that
trips? Is the circuit wired with 2.5mm^2 cable? It may be possible to
replace it with a 20A one, or a "type C" 16A one.

It is a radial with a double 13A socket on it with 2.5mm^2

I will try a type B 20A unless anyone suggests otherwise.

On Sat, 19 Nov 2016 13:09:02 +0000, Andy Burns wrote:

Jack Lawson wrote:

What MCB would you suggest please?

If it's 2.5mm^2 cable you should be fine with a 20A type B (you already
have type B) but it's possible the saw might still trip it.

What's the total length of cable from CU to garage? Someone might do
the calcs to make sure a type C would be safe ...




6ft radial

On 19/11/16 12:56, Jack Lawson wrote:
I assume that I can put a larger MCB in - the cabling is a single spur from the
distribution box to the double socket in the garage - not on a ring.

What MCB would you suggest please?

Others are more expert, but I'd stay with the 16A, but try and get a
type that is 'slow blow' that can take a second of overload.



--
"Women actually are capable of being far more than the feminists will
let them."

Jack Lawson wrote:

6ft radial

For a 20A type C MCB, the maximum Zs is 1.15 ohms to ensure 0.4s trip
time, I think it's fair to say 6' of 2.5mm^s cable meets that
comfortably, 60 metres would be getting marginal!

The Natural Philosopher wrote:

Jack Lawson wrote:

What MCB would you suggest please?

I'd stay with the 16A

a 20A radial is a "standard circuit"

https://www.tlc-direct.co.uk/Book/6.3.3.htm

but try and get a
type that is 'slow blow' that can take a second of overload.

a type C MCB is just that, and with only 6' of cable there's no problem
using either a 16A or 20A.

On Sat, 19 Nov 2016 14:10:54 +0000, Andy Burns wrote:

Jack Lawson wrote:

6ft radial

For a 20A type C MCB, the maximum Zs is 1.15 ohms to ensure 0.4s trip
time, I think it's fair to say 6' of 2.5mm^s cable meets that
comfortably, 60 metres would be getting marginal!


cheers

On 19/11/16 14:25, Andy Burns wrote:
The Natural Philosopher wrote:

Jack Lawson wrote:

What MCB would you suggest please?

I'd stay with the 16A

a 20A radial is a "standard circuit"

https://www.tlc-direct.co.uk/Book/6.3.3.htm

but try and get a
type that is 'slow blow' that can take a second of overload.

a type C MCB is just that, and with only 6' of cable there's no problem
using either a 16A or 20A.

I knew someone would know the correct terminology.



--
Gun Control: The law that ensures that only criminals have guns.

On 19/11/2016 13:50, Jack Lawson wrote:
On Sat, 19 Nov 2016 12:32:29 +0000, Andy Burns wrote:

Jack Lawson wrote:

Tim+ wrote:

Is it definitely a RCD tripping and not just a MCB?

it is in fact a MK (ELECTRIC) 5916S Thermal Magnetic Circuit
Breaker, SENTRY Series, 240 VAC, 16 A, 1 Pole, DIN Rail

Many thanks - problem solved.

Well, mystery solved but problem remains. What else is on the MCB that
trips? Is the circuit wired with 2.5mm^2 cable? It may be possible to
replace it with a 20A one, or a "type C" 16A one.

It is a radial with a double 13A socket on it with 2.5mm^2

I will try a type B 20A unless anyone suggests otherwise.

A B20 (which would ok with 2.5mm^2 T&E in most cases), will allow 100A
of inrush current. A C16 will allow 160A of inrush.

(your current B16 allows 80A)

What kind of motor is in the saw - is it a loud universal brushed motor,
or a quite induction motor?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Fri, 18 Nov 2016 12:02:49 -0000, Jack Lawson wrote:



Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.

Remove the RCD, they're a bloody nuisance as you've found out.

--
I was doing some remolishments to my house the other day and accidentally defurbished it.

On Sat, 19 Nov 2016 02:46:04 -0000, John Rumm wrote:

On 18/11/2016 20:43, Tim Lamb wrote:
In message , ARW
writes
On 18/11/2016 16:17, Tim Lamb wrote:

I have a 9" angle grinder which consistently trips a 20 amp MCB......

You mean it trips a B type 20A MCB?

Yes. Fine elsewhere on re-wireables. Makita.

My workshop socket outlets are end fed so limited to 20 amps.

My previous workshop initially had a 20A MCB protected socket circuit,
and things like my 3kVA site transformer would trip that on switch on
about one time in five. Its fine on a B32 or C20 though.

Fuses don't nuisance trip. Get rid of the newfangled ****.

--
I think car alarms should be set to explode after two minutes.
That way, we either take out a car thief, or deprive a noise-polluting jerk of his wheels.

On Sat, 19 Nov 2016 10:14:30 -0000, "Brian Gaff"
wrote:

Some rcds seem to be a bit sensitive. I have a plug in one on the lawn mower
and its fine but the strimmer trips it for no obvious reason.
Not being sure quite how they detect things when you can get double
insulated, no earth and earthed things to plug in and its still supposed to
work.
Brian

I think the whole point is that they are not supposed to work!

Chopping through the cable with the sharp end of a tool tends to make
the presence of an RCD desirable.

Whether it's a 30mA RCD or 300mA RCD that is required can be
determined using DNA profiling.

Quite a few users of uk.d-i-y would be fine with a 300mA unit :-)


AB


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On 19/11/2016 14:10, Andy Burns wrote:
Jack Lawson wrote:

6ft radial

For a 20A type C MCB, the maximum Zs is 1.15 ohms to ensure 0.4s trip
time, I think it's fair to say 6' of 2.5mm^s cable meets that
comfortably, 60 metres would be getting marginal!


A 16A or 20A C type type will be OK with that sort of run. No
calculations are needed.

A 32A B type will also be OK and will have the added advantage that it
will annoy dennis.



--
Adam

ARW wrote:

Jack Lawson wrote:

6ft radial

A 16A or 20A C type type will be OK with that sort of run. No
calculations are needed.

I thought you might like to break out the adiabatic equation, until Jack
mentioned it was all within reach of the CU!

On 19/11/2016 19:23, Andy Burns wrote:
ARW wrote:

Jack Lawson wrote:

6ft radial

A 16A or 20A C type type will be OK with that sort of run. No
calculations are needed.

I thought you might like to break out the adiabatic equation, until Jack
mentioned it was all within reach of the CU!


No need for all that ********.

However there is a chance that if the OP lives close to a substation
then a short circuit may destroy the MCB. That applies to all circuits
at the house.

--
Adam

On Sat, 19 Nov 2016 18:48:10 +0000, John Rumm
wrote:

snip

I will try a type B 20A unless anyone suggests otherwise.

A B20 (which would ok with 2.5mm^2 T&E in most cases), will allow 100A
of inrush current. A C16 will allow 160A of inrush.

(your current B16 allows 80A)

What kind of motor is in the saw - is it a loud universal brushed motor,
or a quite induction motor?


It is quite noisy 1600 Watt - so guess a universal brushed motor

On 19/11/2016 18:51, James Wilkinson Sword wrote:
On Sat, 19 Nov 2016 02:46:04 -0000, John Rumm
wrote:

On 18/11/2016 20:43, Tim Lamb wrote:
In message , ARW
writes
On 18/11/2016 16:17, Tim Lamb wrote:

I have a 9" angle grinder which consistently trips a 20 amp MCB......

You mean it trips a B type 20A MCB?

Yes. Fine elsewhere on re-wireables. Makita.

My workshop socket outlets are end fed so limited to 20 amps.

My previous workshop initially had a 20A MCB protected socket circuit,
and things like my 3kVA site transformer would trip that on switch on
about one time in five. Its fine on a B32 or C20 though.

Fuses don't nuisance trip.

That is incorrect.

A C16 MCB will have a similar fault trip threshold to a BS3036 15A fuse.

Get rid of the newfangled ****.

Off you go then...

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sat, 19 Nov 2016 23:30:11 -0000, John Rumm wrote:

On 19/11/2016 18:51, James Wilkinson Sword wrote:
On Sat, 19 Nov 2016 02:46:04 -0000, John Rumm
wrote:

On 18/11/2016 20:43, Tim Lamb wrote:
In message , ARW
writes
On 18/11/2016 16:17, Tim Lamb wrote:

I have a 9" angle grinder which consistently trips a 20 amp MCB......

You mean it trips a B type 20A MCB?

Yes. Fine elsewhere on re-wireables. Makita.

My workshop socket outlets are end fed so limited to 20 amps.

My previous workshop initially had a 20A MCB protected socket circuit,
and things like my 3kVA site transformer would trip that on switch on
about one time in five. Its fine on a B32 or C20 though.

Fuses don't nuisance trip.

That is incorrect.

A C16 MCB will have a similar fault trip threshold to a BS3036 15A fuse.

Never seen a fuse blow with anything other than a short.

Get rid of the newfangled ****.

Off you go then...

I've never had an MCB or other crap in my house.

--
"I have left orders to be awakened at any time in case of national emergency, even if I'm in a cabinet meeting." - Ronald Reagan

On Fri, 18 Nov 2016 12:02:49 +0000, Jack Lawson wrote:



Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.

MCB swapped for Type C 32 Amps - job's a good 'un
Thanks to all for advice.

Jack Lawson wrote:

MCB swapped for Type C 32 Amps

32A? Properly you should use 4mm^2 with that.

Could you not get a 16A or 20A type C?

Andy Burns wrote:

Jack Lawson wrote:

MCB swapped for Type C 32 Amps

32A? Properly you should use 4mm^2 with that.

Or make it a very short ring with 2.5mm^2

On 22/11/2016 16:02, Jack Lawson wrote:
On Fri, 18 Nov 2016 12:02:49 +0000, Jack Lawson wrote:



Earlier this week I bought from Homebase a mitre saw:
http://www.homebase.co.uk/en/homebas...s-2125u-389395

I had read reviews and seemed to fit my needs perfectly.
Got it home - and tested it. I found that when I started the saw, it tripped
my RCD on the supply. Tested it further - sometimes it tripped - sometimes
not. This was on initial start-up with no load.
Took it back - got a replacement.
The new one is just the same. About 1 in 10 of start-ups the RCD will trip.
The saw seems perfect for my needs - very accurate mitres and 90 degree cuts
are spot on - I think I will live with what for me is a minor problem - but
thought I'd just share.

MCB swapped for Type C 32 Amps - job's a good 'un


Thanks to all for advice.



No-one suggested that you should fit a C type 32A MCB.



--
Adam

Andy Burns wrote:

Andy Burns wrote:

Jack Lawson wrote:

MCB swapped for Type C 32 Amps

32A? Properly you should use 4mm^2 with that.

Or make it a very short ring with 2.5mm^2

We've established upthread that the 2.5^2 is short enough.

--

Roger Hayter

On 22/11/2016 20:23, Roger Hayter wrote:
Andy Burns wrote:

Andy Burns wrote:

Jack Lawson wrote:

MCB swapped for Type C 32 Amps

32A? Properly you should use 4mm^2 with that.

Or make it a very short ring with 2.5mm^2

We've established upthread that the 2.5^2 is short enough.


Not short enough for a C type 32A MCB on a TN-S supply that is at the
upper limits of it's maximum allowed Zs.

--
Adam

On 22/11/2016 17:13, Andy Burns wrote:
Andy Burns wrote:

Jack Lawson wrote:

MCB swapped for Type C 32 Amps

32A? Properly you should use 4mm^2 with that.

Or make it a very short ring with 2.5mm^2

If its a short radial with only one double socket on it, then the MCB is
only required for fault protection anyway.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In message , ARW
writes
On 19/11/2016 19:23, Andy Burns wrote:
ARW wrote:

Jack Lawson wrote:

6ft radial

A 16A or 20A C type type will be OK with that sort of run. No
calculations are needed.

I thought you might like to break out the adiabatic equation, until Jack
mentioned it was all within reach of the CU!


No need for all that ********.

However there is a chance that if the OP lives close to a substation
then a short circuit may destroy the MCB. That applies to all circuits
at the house.

As I was in the workshop this evening I thought I should check my claim
about my 9" angle grinder tripping the supply. Er... the MCB is in fact
a 16amp B type....


--
Tim Lamb