Discussion:
RCBO v. mini-RCBO
(too old to reply)
PeterC
2020-11-15 08:20:23 UTC
Permalink
I've just bought some miniature RCBOs to replace MCBs in my CU - the
lighting circuits are on a 100mA RCD as is a spur to a socket in the
loft(!).

In a c. 1990 CU there isn't space for full-size RCBOs whereas the minis will
fit.
What I can't find out is if there's any disadvantage to a mini over a
full-sized one. So far as I can see there are some advantages:
tend to be cheaper
fit in the CU
effectively double pole
don't need to be disconnected when running tests

What am I missing on this? What's the point of big RCBOs?
--
Peter.
The gods will stay away
whilst religions hold sway
Andy Burns
2020-11-15 08:56:57 UTC
Permalink
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second generation, so I don't think there's
any 'point' as such to the tall ones.
ARW
2020-11-15 12:35:18 UTC
Permalink
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second  generation, so I don't think there's
any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
--
Adam
PeterC
2020-11-15 13:06:25 UTC
Permalink
Post by ARW
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second  generation, so I don't think there's
any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
Looking at the manufacturer's site for Wylex and Crabtree, neither do the
big ones.
The full-size ones mention disconnection before testing the circuit; the
miniature ones don't.
--
Peter.
The gods will stay away
whilst religions hold sway
The Natural Philosopher
2020-11-15 14:12:14 UTC
Permalink
Post by ARW
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second  generation, so I don't think
there's any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
No RCD/RCBO has a 'functional earth fly lead'.
--
I would rather have questions that cannot be answered...
...than to have answers that cannot be questioned

Richard Feynman
Andy Burns
2020-11-15 14:15:50 UTC
Permalink
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...

<https://www.circpro.co.uk/mk-sentry-rcbo>
The Natural Philosopher
2020-11-15 14:55:07 UTC
Permalink
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
--
The biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.
ARW
2020-11-15 15:14:39 UTC
Permalink
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.

RCD's do not have these fly leads.

And wankers oversleeve the flyleads with green/yellow. But then some
RCBO manufactures have a flylead with a green/yellow cable.
--
Adam
PeterC
2020-11-15 22:10:36 UTC
Permalink
Post by ARW
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.
RCD's do not have these fly leads.
And wankers oversleeve the flyleads with green/yellow. But then some
RCBO manufactures have a flylead with a green/yellow cable.
Can that fly lead have a DIY equivalent wired into a mini-RCBO? I can't see
from the image that Andy posted what it's connected to on the RCBO.
--
Peter.
The gods will stay away
whilst religions hold sway
Mathew Newton
2020-11-15 22:19:40 UTC
Permalink
Post by PeterC
Can that fly lead have a DIY equivalent wired into a mini-RCBO? I can't see
from the image that Andy posted what it's connected to on the RCBO.
No. (It'd have to be connected internally to the imbalance detection circuit).
PeterC
2020-11-16 08:53:59 UTC
Permalink
Post by Mathew Newton
Post by PeterC
Can that fly lead have a DIY equivalent wired into a mini-RCBO? I can't see
from the image that Andy posted what it's connected to on the RCBO.
No. (It'd have to be connected internally to the imbalance detection circuit).
I see - thanks.
--
Peter.
The gods will stay away
whilst religions hold sway
williamwright
2020-11-16 03:54:44 UTC
Permalink
Post by ARW
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.
RCD's do not have these fly leads.
And wankers oversleeve the flyleads with green/yellow. But then some
RCBO manufactures have a flylead with a green/yellow cable.
Glad you came along Adam!

Bill
The Natural Philosopher
2020-11-16 08:41:23 UTC
Permalink
Post by ARW
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.
You haven't looked at the circuit diagram have you?
Or thought about what you just said.

How is the current - the massive current - that should flow down the
neutral going to get back to base if there is no neutral?

Down that poxy little wire to *earth*? What????
Earth is simply safety, it never passes significant current except under
fault conditions. You cant operate *at all* without a neutral.
--
“Progress is precisely that which rules and regulations did not foresee,”

– Ludwig von Mises
John Rumm
2020-11-17 08:35:44 UTC
Permalink
Post by The Natural Philosopher
Post by ARW
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.
You haven't looked at the circuit diagram have you?
Or thought about what you just said.
How is the current  - the massive current - that should flow down the
neutral going to get back to base if there is no neutral?
Its not.
Post by The Natural Philosopher
Down that poxy little wire to *earth*? What????
No, and it does not need to either.
Post by The Natural Philosopher
Earth is simply safety,
Not true of a functional earth - you are thinking of a protective earth.

When you make the earth connection between your turntable and amp, is
that for safety?
Post by The Natural Philosopher
it never passes significant current except under
fault conditions.
Its not a protective earth, so won't ever pass a significant current
even under fault conditions.
Post by The Natural Philosopher
You cant operate *at all* without a neutral.
You can if you have a functional earth, that is one of the reasons for
having it[1].

Even in even in the event of a PEN conductor disconnection on a TN-C-S
supply, that functional earth should still have *some* fortuitous
earthing via the main equipotential bonds etc. That will allow adequate
current to be drawn by the electronics in the RCBO to detect the fault,
and trip.

[1] One might argue the benefits, since the loss of neutral is rare, and
adding an extra connection makes the job of wiring more time consuming
and also makes testing more complicated since the FE will likely need to
be disconnected for IR and earth loop testing. However others would cite
that reports of loss of neutral still occur about once a day somewhere
in the UK.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
John Rumm
2020-11-17 02:42:29 UTC
Permalink
Post by ARW
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.
RCD's do not have these fly leads.
And wankers oversleeve the flyleads with green/yellow. But then some
RCBO manufactures have a flylead with a green/yellow cable.
Probably worth highlighting the reason for Adam's indignation regarding
over sleeving. While the correct colour sleeving for a protective
conductor is the normal green/yellow, the correct colour for a
functional earth is actually cream.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Andy Burns
2020-11-17 06:51:00 UTC
Permalink
Post by John Rumm
Probably worth highlighting the reason for Adam's indignation regarding
over sleeving. While the correct colour sleeving for a protective
conductor is the normal green/yellow, the correct colour for a
functional earth is actually cream.
Although the printing on that RCBO actually says 'PE' instead of 'FE'
for the white flylead.

and the text within the little box connected to the current transformer
and the earth flylead says "1Δ" instead of the expected "IΔ"

Original image URL (will be zoomable unless you have a portrait monitor).

<https://images.squarespace-cdn.com/content/v1/5ec649c17e93ee14ea6f1a9b/1594219056973-3YJBH0HJX2Y5AZISSGW8/ke17ZwdGBToddI8pDm48kPlAdDxmOe2wO-VlVH21GUIUqsxRUqqbr1mOJYKfIPR7LoDQ9mXPOjoJoqy81S2I8PaoYXhp6HxIwZIk7-Mi3Tsic-L2IOPH3Dwrhl-Ne3Z2KbNUfoO6AOkUKHX6DcHzYjCBx_xjkpU-kAGxUEirxz46liCGkj4dr9PBmyqqYlee/6310S.jpg>

Note that MK Sentry range is now licenced for CircPro to
manufacture/sell rather than being a Honeywell brand.
ARW
2020-11-17 18:48:18 UTC
Permalink
Post by Andy Burns
Post by John Rumm
Probably worth highlighting the reason for Adam's indignation
regarding over sleeving. While the correct colour sleeving for a
protective conductor is the normal green/yellow, the correct colour
for a functional earth is actually cream.
Although the printing on that RCBO actually says 'PE' instead of 'FE'
for the white flylead.
and the text within the little box connected to the current transformer
and the earth flylead says "1Δ" instead of the expected "IΔ"
Original image URL (will be zoomable unless you have a portrait monitor).
<https://images.squarespace-cdn.com/content/v1/5ec649c17e93ee14ea6f1a9b/1594219056973-3YJBH0HJX2Y5AZISSGW8/ke17ZwdGBToddI8pDm48kPlAdDxmOe2wO-VlVH21GUIUqsxRUqqbr1mOJYKfIPR7LoDQ9mXPOjoJoqy81S2I8PaoYXhp6HxIwZIk7-Mi3Tsic-L2IOPH3Dwrhl-Ne3Z2KbNUfoO6AOkUKHX6DcHzYjCBx_xjkpU-kAGxUEirxz46liCGkj4dr9PBmyqqYlee/6310S.jpg>
Note that MK Sentry range is now licenced for CircPro to
manufacture/sell rather than being a Honeywell brand.
MK pulled out of the CU market last year. It was posted on here.
Probably just before we went to the Elex show.
--
Adam
Andy Burns
2020-11-17 18:59:38 UTC
Permalink
Post by ARW
MK pulled out of the CU market last year. It was posted on here.
Probably just before we went to the Elex show.
But the MK sentry brand is now back ... licenced by Honeywell to
CircPro, who apparently are the people who were making the sentry range
all along!

<https://www.circpro.co.uk>
ARW
2020-11-17 19:53:50 UTC
Permalink
Post by Andy Burns
Post by ARW
MK pulled out of the CU market last year. It was posted on here.
Probably just before we went to the Elex show.
But the MK sentry brand is now back ... licenced by Honeywell to
CircPro, who apparently are the people who were making the sentry range
all along!
<https://www.circpro.co.uk>
I wonder who is making the SPDs?
--
Adam
Andy Burns
2020-11-17 20:11:45 UTC
Permalink
Post by ARW
I wonder who is making the SPDs?
strangely they seem to be black rather than pale grey.

<Loading Image...>

these look quite similar, not identical though

<Loading Image...>
Adam Funk
2020-11-24 17:01:25 UTC
Permalink
Post by John Rumm
Post by ARW
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.
RCD's do not have these fly leads.
And wankers oversleeve the flyleads with green/yellow. But then some
RCBO manufactures have a flylead with a green/yellow cable.
Probably worth highlighting the reason for Adam's indignation regarding
over sleeving. While the correct colour sleeving for a protective
conductor is the normal green/yellow, the correct colour for a
functional earth is actually cream.
Is this "functional earth" in the sense of reducing interference (like
AV interference)?
John Rumm
2020-11-25 01:56:02 UTC
Permalink
Post by Adam Funk
Post by John Rumm
Post by ARW
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
It allows the RCBO to continue working and detect a LE fault in the
unlikely event of a missing/lost neutral.
RCD's do not have these fly leads.
And wankers oversleeve the flyleads with green/yellow. But then some
RCBO manufactures have a flylead with a green/yellow cable.
Probably worth highlighting the reason for Adam's indignation regarding
over sleeving. While the correct colour sleeving for a protective
conductor is the normal green/yellow, the correct colour for a
functional earth is actually cream.
Is this "functional earth" in the sense of reducing interference (like
AV interference)?
Yes, basically any earth that is not just there to carry a fault current.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Andy Burns
2020-11-15 15:40:32 UTC
Permalink
Post by The Natural Philosopher
Post by Andy Burns
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function.
Zoom in ... it's shown as part of the circuitry measuring current
differences

<Loading Image...>
Post by The Natural Philosopher
No idea what its for, perhaps to
earth something in the switch...
The Natural Philosopher
2020-11-16 08:43:07 UTC
Permalink
Post by Andy Burns
Post by The Natural Philosopher
Post by Andy Burns
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function.
Zoom in ... it's shown as part of the circuitry measuring current
differences
I did and its clearly there to earth a bit of metal in there.

THINK. How COULD it be part of it. If it passes any current at all it is
CREATING an earth fault.
Post by Andy Burns
<https://images.squarespace-cdn.com/content/v1/5ec649c17e93ee14ea6f1a9b/1594219056973-3YJBH0HJX2Y5AZISSGW8/ke17ZwdGBToddI8pDm48kPlAdDxmOe2wO-VlVH21GUIUqsxRUqqbr1mOJYKfIPR7LoDQ9mXPOjoJoqy81S2I8PaoYXhp6HxIwZIk7-Mi3Tsic-L2IOPH3Dwrhl-Ne3Z2KbNUfoO6AOkUKHX6DcHzYjCBx_xjkpU-kAGxUEirxz46liCGkj4dr9PBmyqqYlee/6310S.jpg>
Post by The Natural Philosopher
No idea what its for, perhaps to earth something in the switch...
--
Truth welcomes investigation because truth knows investigation will lead
to converts. It is deception that uses all the other techniques.
Roger Hayter
2020-11-16 09:43:11 UTC
Permalink
On 16 Nov 2020 at 08:43:07 GMT, "The Natural Philosopher"
Post by The Natural Philosopher
Post by Andy Burns
Post by The Natural Philosopher
Post by Andy Burns
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function.
Zoom in ... it's shown as part of the circuitry measuring current
differences
I did and its clearly there to earth a bit of metal in there.
THINK. How COULD it be part of it. If it passes any current at all it is
CREATING an earth fault.
All they have to do is draw the current for the electronics *before* the
imbalance detector.
--
Roger Hayter
The Natural Philosopher
2020-11-16 11:07:10 UTC
Permalink
Post by Roger Hayter
On 16 Nov 2020 at 08:43:07 GMT, "The Natural Philosopher"
Post by The Natural Philosopher
Post by Andy Burns
Post by The Natural Philosopher
Post by Andy Burns
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function.
Zoom in ... it's shown as part of the circuitry measuring current
differences
I did and its clearly there to earth a bit of metal in there.
THINK. How COULD it be part of it. If it passes any current at all it is
CREATING an earth fault.
All they have to do is draw the current for the electronics *before* the
imbalance detector.
WHAT electronics?
--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."

Lucas Bergkamp
Andy Burns
2020-11-16 11:12:26 UTC
Permalink
Post by The Natural Philosopher
Post by Roger Hayter
Post by The Natural Philosopher
THINK. How COULD it be part of it. If it passes any current at all it is
CREATING an earth fault.
All they have to do is draw the current for the electronics *before* the
imbalance detector.
WHAT electronics?
THESE electronics ... the white earth flylead seems to connect to a pin
on the balance transformer (whatever the correct term might be)


Andy Burns
2020-11-16 11:18:22 UTC
Permalink
Post by Andy Burns
he white earth flylead seems to connect to a pin
on the balance transformer (whatever the correct term might be)
no, it might only go to the other circuitry on the PCB, not to the
windings ...
ARW
2020-11-16 17:10:37 UTC
Permalink
Post by Andy Burns
he white earth flylead seems to connect to a pin on the balance
transformer (whatever the correct term might be)
no, it might only go to the other circuitry on the PCB, not to the
windings ...

--
Adam
Andy Burns
2020-11-16 17:29:37 UTC
Permalink
Post by ARW
Post by Andy Burns
he white earth flylead seems to connect to a pin on the balance
transformer (whatever the correct term might be)
no, it might only go to the other circuitry on the PCB, not to the
windings ...
http://youtu.be/gOUSDDLKICk
makes sense, and the IC uses a SCR to "crowbar" live to neutral if it
detects an imbalance fault, it won't draw current for very long over the
thin white wire ...
The Natural Philosopher
2020-11-16 12:11:33 UTC
Permalink
Post by Andy Burns
Post by The Natural Philosopher
Post by Roger Hayter
Post by The Natural Philosopher
THINK. How COULD it be part of it. If it passes any current at all it is
CREATING an earth fault.
All they have to do is draw the current for the electronics *before* the
imbalance detector.
WHAT electronics?
THESE electronics ... the white earth flylead seems to connect to a pin
on the balance transformer (whatever the correct term might be)
http://youtu.be/8kWIITspYvk
Blimey. I'll concede that. They have devloped since my time...BUT if
you look at the circuit diagram later in that video, you will see than
no earth is involved. The only possible thing it *might* do is nothing
to do with RCD detection per se, but it MIGHT detect voltage on the
neutral with respect to earth.

Not something that bothers me at all.
--
"I guess a rattlesnake ain't risponsible fer bein' a rattlesnake, but ah
puts mah heel on um jess the same if'n I catches him around mah chillun".
Andy Burns
2020-11-16 12:55:10 UTC
Permalink
Post by The Natural Philosopher
Blimey.
Imagine what AFDDs are going to be like, a DSP to discriminate between
harmless sparks and fiery sparks?
Post by The Natural Philosopher
I'll concede  that. They have devloped since my time...BUT if
you look at the circuit diagram later in that video, you will see than
no earth is involved.
Yes, the reference circuit for the chip shows it has a "substrate ground"

<http://eng.fmsh.com/AjaxFile/DownLoadFile.aspx?FilePath=/UpLoadFile/20140904/VG54123_ds_eng.pdf&fileExt=file>

but no PE or FE earth connection, makes you wonder if MK have added
something extra on the PCB for lost-neutral detection?
Post by The Natural Philosopher
The only possible thing it *might* do is nothing
to do with RCD detection per se,  but it MIGHT detect voltage on the
neutral with respect to earth.
Not something that bothers me at all.
John Rumm
2020-11-17 11:07:05 UTC
Permalink
Post by Andy Burns
Post by The Natural Philosopher
Blimey.
Imagine what AFDDs are going to be like, a DSP to discriminate between
harmless sparks and fiery sparks?
Post by The Natural Philosopher
I'll concede  that. They have devloped since my time...BUT if you look
at the circuit diagram later in that video, you will see than no earth
is involved.
Yes, the reference circuit for the chip shows it has a "substrate ground"
<http://eng.fmsh.com/AjaxFile/DownLoadFile.aspx?FilePath=/UpLoadFile/20140904/VG54123_ds_eng.pdf&fileExt=file>
but no PE or FE earth connection, makes you wonder if MK have added
something extra on the PCB for lost-neutral detection?
There is no actual requirement for a RCBO to have a FE connection (and
indeed many brands don't), however if its present, then the standards do
have things to say about how it should work IIUC.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Andy Burns
2020-11-17 11:33:49 UTC
Permalink
Post by John Rumm
There is no actual requirement for a RCBO to have a FE connection (and
indeed many brands don't), however if its present, then the standards do
have things to say about how it should work IIUC.
I couldn't see any mention of PE or FE in BS EN 61009-1, other than in
deleted wording.
John Rumm
2020-11-17 12:32:31 UTC
Permalink
Post by Andy Burns
Post by John Rumm
There is no actual requirement for a RCBO to have a FE connection (and
indeed many brands don't), however if its present, then the standards
do have things to say about how it should work IIUC.
I couldn't see any mention of PE or FE in BS EN 61009-1, other than in
deleted wording.
The 2004 version has a requirement to use label the terminal with the
protective earth icon as per IEC 60417-5019a rather than the functional
earth symbol as previously recommended!

Can't recall where I did see mention of it now.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Andrew
2020-11-17 14:00:00 UTC
Permalink
Post by John Rumm
Post by Andy Burns
Post by John Rumm
There is no actual requirement for a RCBO to have a FE connection
(and indeed many brands don't), however if its present, then the
standards do have things to say about how it should work IIUC.
I couldn't see any mention of PE or FE in BS EN 61009-1, other than in
deleted wording.
The 2004 version has a requirement to use label the terminal with the
protective earth icon as per IEC 60417-5019a rather than the functional
earth symbol as previously recommended!
Can't recall where I did see mention of it now.
Do RCBO's still consume power even when no user devices are
using power ?.
Assuming 6 in the consumer unit of a typical average house,
how much leccy is used per year ?.
Andy Burns
2020-11-17 14:33:35 UTC
Permalink
Post by Andrew
Do RCBO's still consume power even when no user devices are
using power ?.
Yes
Post by Andrew
Assuming 6 in the consumer unit of a typical average house,
how much leccy is used per year ?.
The chip used on the PCB says max 10mA consumption, so that's a couple
of watts per RCBO, I doubt anything else on the PCB consumes much unless
it's in the act of tripping, so one or two quid each per year?
John Rumm
2020-11-17 18:47:30 UTC
Permalink
Post by Andrew
Post by John Rumm
Post by Andy Burns
Post by John Rumm
There is no actual requirement for a RCBO to have a FE connection
(and indeed many brands don't), however if its present, then the
standards do have things to say about how it should work IIUC.
I couldn't see any mention of PE or FE in BS EN 61009-1, other than
in deleted wording.
The 2004 version has a requirement to use label the terminal with the
protective earth icon as per IEC 60417-5019a rather than the
functional earth symbol as previously recommended!
Can't recall where I did see mention of it now.
Do RCBO's still consume power even when no user devices are
using power ?.
Yup that have "always on" electronics - so will consume a very small
amount same as any RCD.

(The MCB element will also dissipate a certain amount of heat when on
high load since this is a function of how the thermal part of its trip
mechanism works)
Post by Andrew
Assuming 6 in the consumer unit of a typical average house,
how much leccy is used per year ?.
Finding data for the power consumption or the RCD elements themselves is
actually quite tricky. ISTR Wylex publishing a figure of between 1.5 and
2.5W per RCBO depending on load.

So if we said it was 10W total for your 6 circuit CU, that would be 1kWh
every 100h operation, or ~87 kWh - could be £10 or so depending on your
unit price.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
John Rumm
2020-11-15 17:58:57 UTC
Permalink
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
....is not part of the trip function.
It is - but it adds a capability that normal RCDs don't have.
No idea what its for, perhaps to
earth something in the switch...
It will allow it to trip in the unlikely event that you get a neutral
disconnection. (which on a PME supply could leave all earthed metalwork
in the house at mains voltage)
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Andy Burns
2020-12-15 19:43:18 UTC
Permalink
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...

The Natural Philosopher
2020-12-16 02:48:58 UTC
Permalink
Post by Andy Burns
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
http://youtu.be/aCf2alTZkLU
Blimey. so it's there to detect neutral earth current for if the neutral
is disconnected.
--
Religion is regarded by the common people as true, by the wise as
foolish, and by the rulers as useful.

(Seneca the Younger, 65 AD)
Andy Bennet
2020-12-16 07:37:26 UTC
Permalink
Post by The Natural Philosopher
Post by Andy Burns
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
http://youtu.be/aCf2alTZkLU
Blimey. so it's there to detect neutral earth current for if the neutral
is disconnected.
And if the functional earth is not made/drops off/doesn't go to earth
the RCBO 'may not work as normal'. Hmm. I think you have a lower
probability of killing yourself with the non earthed type!
The Natural Philosopher
2020-12-16 08:04:16 UTC
Permalink
Post by Andy Bennet
Post by The Natural Philosopher
Post by Andy Burns
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps
to earth something in the switch...
http://youtu.be/aCf2alTZkLU
Blimey. so it's there to detect neutral earth current for if the
neutral is disconnected.
And if the functional earth is not made/drops off/doesn't go to earth
the RCBO 'may not work as normal'. Hmm. I think you have a lower
probability of killing yourself with the non earthed type!
THAT is just bullshit. Designed to get you to use their crap
--
“The ultimate result of shielding men from the effects of folly is to
fill the world with fools.”

Herbert Spencer
John Rumm
2020-12-16 15:56:48 UTC
Permalink
Post by The Natural Philosopher
Post by Andy Burns
Post by The Natural Philosopher
Post by Andy Burns
Post by ARW
The small ones often do not have the functional earth fly lead.
No RCD/RCBO  has a 'functional earth fly lead'.
The white lead here ...
...is not part of the trip function. No idea what its for, perhaps to
earth something in the switch...
http://youtu.be/aCf2alTZkLU
Blimey. so it's there to detect neutral earth current for if the neutral
is disconnected.
No it's there to detect Live to earth leakage when there is no neutral
connection, something a regular RCD may not be able to do.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Andy Burns
2020-12-17 10:14:05 UTC
Permalink
Post by ARW
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second  generation, so I don't think
there's any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
Apparently Chint can squeeze a 3-ph RCBO into a single-width module ...

<https://screwfix.com/c/c/c/cat7230024#&brand=chint>
Peter Burke
2020-12-17 14:53:17 UTC
Permalink
Post by Andy Burns
Post by ARW
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second  generation, so I don't think
there's any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
Apparently Chint can squeeze a 3-ph RCBO into a single-width module ...
<https://screwfix.com/c/c/c/cat7230024#&brand=chint>
Seems Screwfix is becoming quite the specialist electrical supplier with
33 of their 105 RCBOs now 3ph and a choice of 3 makes on offer.

The Chint is both 3ph & 1 pole, neat space saving trick.

They're doing pre-stripped (as opposed to striped) earth wire too, that
will save some work.

More seriously, it's good to see that 3ph RCBOs are becoming available
(Hager etc), a pal had a holiday cottages setup with swimming pool and he
had a hell of a job tracking down some nuisance trips through all of the
water based elements running off single RCDs. I wanted to suggest
converting his board to 3ph RCBOs but I couldn't find any (this was a
while ago).
Andy Burns
2020-12-17 15:34:53 UTC
Permalink
it's good to see that 3ph RCBOs are becoming available (Hager etc)
The schneider 3P+N RCD/MCB combo is 7 modules wide though.
Peter Burke
2020-12-17 16:34:44 UTC
Permalink
Post by Andy Burns
it's good to see that 3ph RCBOs are becoming available (Hager etc)
The schneider 3P+N RCD/MCB combo is 7 modules wide though.
Ouch! Sounds like a bit of a bodge.

Hager & Eaton look to be 4 modules wide so more sensible.

Haven't bothered to look at the specs in detail as no 3ph here and have
rather lost touch with Mr Pool.
Andy Burns
2020-12-17 16:44:21 UTC
Permalink
Post by Peter Burke
Post by Andy Burns
The schneider 3P+N RCD/MCB combo is 7 modules wide though.
Ouch! Sounds like a bit of a bodge.

Peter Burke
2020-12-17 18:26:22 UTC
Permalink
Post by Andy Burns
Post by Peter Burke
Post by Andy Burns
The schneider 3P+N RCD/MCB combo is 7 modules wide though.
Ouch! Sounds like a bit of a bodge.
http://youtu.be/e54ud_CIvEU
That looks horrible. The distribution boards will be twice the size.
ARW
2020-12-17 18:40:54 UTC
Permalink
Post by Andy Burns
Post by Peter Burke
Post by Andy Burns
The schneider 3P+N RCD/MCB combo is 7 modules wide though.
Ouch! Sounds like a bit of a bodge.
http://youtu.be/e54ud_CIvEU
It's the Chuckle Brothers
--
Adam
ARW
2020-12-17 18:39:11 UTC
Permalink
Post by Andy Burns
Post by ARW
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second  generation, so I don't think
there's any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
Apparently Chint can squeeze a 3-ph RCBO into a single-width module ...
<https://screwfix.com/c/c/c/cat7230024#&brand=chint>
:-)))))))))))))))))
--
Adam
charles
2020-12-17 18:47:11 UTC
Permalink
Post by ARW
Post by Andy Burns
Post by ARW
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second generation, so I don't think
there's any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
Apparently Chint can squeeze a 3-ph RCBO into a single-width module ...
<https://screwfix.com/c/c/c/cat7230024#&brand=chint>
:-)))))))))))))))))
When you click on the picture for detailed description, it says "single
pole".
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
Fredxx
2020-12-18 00:43:56 UTC
Permalink
Post by charles
Post by ARW
Post by Andy Burns
Post by ARW
Post by Andy Burns
Post by PeterC
What's the point of big RCBOs?
I think the first generation RCBOs were taller, then they managed to
shrink them to MCB size in second generation, so I don't think
there's any 'point' as such to the tall ones.
The small ones often do not have the functional earth fly lead.
Apparently Chint can squeeze a 3-ph RCBO into a single-width module ...
<https://screwfix.com/c/c/c/cat7230024#&brand=chint>
:-)))))))))))))))))
When you click on the picture for detailed description, it says "single
pole".
It says
No. of Phases 3-Phase
Number of Poles Single Pole

One might be forgiven, if they didn't see the photo, that it was for a
3-phase supply, where you might expect 3 single pole contacts.

It's a term not confined to Screwfix:

https://www.electricaldirect.co.uk/product/eaton-mem-63a-single-pole-3-phase-mcb-type-c-862054
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