In article ,
ARW wrote:
And the reason I posted is because I found a LN reversal on a socket
during a EICR.

The tenant was adamant a rectifier would not work.

I was convinced it would (even after a bottle wine of when I posted).

So I asked the collective wisdom of you fine posters.

I'm trying to think of *any* domestic equipment that wouldn't work if the
line and neutral are reversed?

--
*Ah, I see the f**k-up fairy has visited us again

Dave Plowman London SW
To e-mail, change noise into sound.

On 9 Apr 2021 at 11:08:18 BST, ""Dave Plowman" News)"
wrote:

In article ,
ARW wrote:
And the reason I posted is because I found a LN reversal on a socket
during a EICR.

The tenant was adamant a rectifier would not work.

I was convinced it would (even after a bottle wine of when I posted).

So I asked the collective wisdom of you fine posters.

I'm trying to think of *any* domestic equipment that wouldn't work if the
line and neutral are reversed?

The exception would be a half-wave rectifier when the 'cold' side of the
rectified supply was earthed. This would be illegal, I think, but it would
definitely not work if live and neutral reversed. And if, in normal use, the
neutral was connected to the earthed chassis then bad things would happen if
the mains was reversed. Of course, in that scenario any RCD on the supply
might well be tripped in normal use, and the normal use would be even more
illegal.

--
Roger Hayter

On 09/04/2021 12:38, Roger Hayter wrote:
On 9 Apr 2021 at 11:08:18 BST, ""Dave Plowman" News)"
wrote:

In article ,
ARW wrote:
And the reason I posted is because I found a LN reversal on a socket
during a EICR.

The tenant was adamant a rectifier would not work.

I was convinced it would (even after a bottle wine of when I posted).

So I asked the collective wisdom of you fine posters.

I'm trying to think of *any* domestic equipment that wouldn't work if the
line and neutral are reversed?

The exception would be a half-wave rectifier when the 'cold' side of the
rectified supply was earthed.


Such as? I also cannot think of any domestic equipment that wouldn't work.

That doesn't mean that domestic equipment doesn't reverse what seems
common-sense by design. My gas boiler has all of its electronics
referenced to the LINE potential.

Guess how I found that out !

PA

On 09/04/2021 13:33, Peter Able wrote:
On 09/04/2021 12:38, Roger Hayter wrote:
On 9 Apr 2021 at 11:08:18 BST, ""Dave Plowman" News)"

wrote:

In article ,
Â*Â*Â* ARW wrote:
Â* And the reason I posted is because I found a LN reversal on a socket
Â* during a EICR.

Â* The tenant was adamant a rectifier would not work.

Â* I was convinced it would (even after a bottle wine of when I posted).

Â* So I asked the collective wisdom of you fine posters.

I'm trying to think of *any* domestic equipment that wouldn't work if
the
line and neutral are reversed?

The exception would be a half-wave rectifier when the 'cold' side of the
rectified supply was earthed.


Such as?Â* I also cannot think of any domestic equipment that wouldn't work.

That doesn't mean that domestic equipment doesn't reverse what seems
common-sense by design.Â* My gas boiler has all of its electronics
referenced to the LINE potential.

Guess how I found that out !

It would not spark?



--
Adam

On 09/04/2021 13:33, Peter Able wrote:
On 09/04/2021 12:38, Roger Hayter wrote:
On 9 Apr 2021 at 11:08:18 BST, ""Dave Plowman" News)"

wrote:

In article ,
Â*Â*Â* ARW wrote:
Â* And the reason I posted is because I found a LN reversal on a socket
Â* during a EICR.

Â* The tenant was adamant a rectifier would not work.

Â* I was convinced it would (even after a bottle wine of when I posted).

Â* So I asked the collective wisdom of you fine posters.

I'm trying to think of *any* domestic equipment that wouldn't work if
the
line and neutral are reversed?

The exception would be a half-wave rectifier when the 'cold' side of the
rectified supply was earthed.


Such as?Â* I also cannot think of any domestic equipment that wouldn't work.

That doesn't mean that domestic equipment doesn't reverse what seems
common-sense by design.Â* My gas boiler has all of its electronics
referenced to the LINE potential.

Guess how I found that out !

On many boilers the flame detection is achieved by flame rectification
between the ignition electrode and earth - I can see that failing if the
wrong end of it is effectively at earth potential.


--
Cheers,

John.

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

On 08/04/2021 21:58, Max Demian wrote:
On 08/04/2021 17:55, ARW wrote:
On 08/04/2021 01:04, Fredxx wrote:
On 07/04/2021 22:12, Robin wrote:
On 07/04/2021 21:46, Fredxx wrote:
On 07/04/2021 21:42, ARW wrote:
Am I correct in saying that it does not matter if there is a LN
reversal on the input?

It will always have a correct +/- DC voltage.

The DC voltage across the capacitor will be the same, the
difference: one way it will be referenced to neutral, ie close to
ground, and the other will have 230V superimposed on the capacitor
terminals.

I'd assumed Adam meant a bridge rectifier as in

https://www.electronics-tutorials.ws...?fit=331%2C191


but I am prone to be wrong

I saw "full wave rectifier" and thought "single diode". My bad, I
should try reading a little harder.

In which case L-N reversal will make no difference.

Your link is spot on.

And the reason I posted is because I found a LN reversal on a socket
during a EICR.

The tenant was adamant a rectifier would not work.

I was convinced it would (even after a bottle wine of when I posted).

So I asked the collective wisdom of you fine posters.

He clearly doesn't understand what AC stands for, and/or what a
rectifier does.


He was an A level physics teacher which probably made me think he might
have had some understanding of the subject.

--
Adam

On 09/04/2021 18:41, ARW wrote:
On 09/04/2021 13:33, Peter Able wrote:
On 09/04/2021 12:38, Roger Hayter wrote:
On 9 Apr 2021 at 11:08:18 BST, ""Dave Plowman" News)"

wrote:

In article ,
Â*Â*Â* ARW wrote:
Â* And the reason I posted is because I found a LN reversal on a socket
Â* during a EICR.

Â* The tenant was adamant a rectifier would not work.

Â* I was convinced it would (even after a bottle wine of when I
posted).

Â* So I asked the collective wisdom of you fine posters.

I'm trying to think of *any* domestic equipment that wouldn't work
if the
line and neutral are reversed?

The exception would be a half-wave rectifier when the 'cold' side of the
rectified supply was earthed.


Such as?Â* I also cannot think of any domestic equipment that wouldn't
work.

That doesn't mean that domestic equipment doesn't reverse what seems
common-sense by design.Â* My gas boiler has all of its electronics
referenced to the LINE potential.

Guess how I found that out !

It would not spark?



No, it was me that sparked when first diagnosing the controller PCB! A
crazy system. From the neutral a 0u68 capacitor then two zeners in
serial-opposition to the LINE. Two diodes picking off the clamped AC to
offer +/- supplies for the electronics.

Needless to say, the capacitor (right on top of the heat-exchanger -
natch) has dropped in value, twice, making the boiler dance a fandango
once the regulator on the electronics plus supply runs out of input voltage.

Cowboys !

PA

On 09/04/2021 18:41, John Rumm wrote:
On 09/04/2021 13:33, Peter Able wrote:
On 09/04/2021 12:38, Roger Hayter wrote:
On 9 Apr 2021 at 11:08:18 BST, ""Dave Plowman" News)"

wrote:

In article ,
Â*Â*Â* ARW wrote:
Â* And the reason I posted is because I found a LN reversal on a socket
Â* during a EICR.

Â* The tenant was adamant a rectifier would not work.

Â* I was convinced it would (even after a bottle wine of when I
posted).

Â* So I asked the collective wisdom of you fine posters.

I'm trying to think of *any* domestic equipment that wouldn't work
if the
line and neutral are reversed?

The exception would be a half-wave rectifier when the 'cold' side of the
rectified supply was earthed.


Such as?Â* I also cannot think of any domestic equipment that wouldn't
work.

That doesn't mean that domestic equipment doesn't reverse what seems
common-sense by design.Â* My gas boiler has all of its electronics
referenced to the LINE potential.

Guess how I found that out !

On many boilers the flame detection is achieved by flame rectification
between the ignition electrode and earth - I can see that failing if the
wrong end of it is effectively at earth potential.



And this boiler uses that sort of flame detection - but I was shocked,
in both senses, when I first had to diagnose the control PCB. (See my
other comment to Max).

"Pancho" wrote in message
...
On 08/04/2021 15:49, Peter Able wrote:


The OP mentions "LN reversal" so this thread is about mains. He also
mentions a "smoothing capacitor" - so it is AC Mains he is asking about.


Why does that mean AC Mains, as opposed to any AC rectification?

Because you dont call the output of a transformer LN.

ARW wrote:
On 08/04/2021 21:58, Max Demian wrote:
On 08/04/2021 17:55, ARW wrote:
On 08/04/2021 01:04, Fredxx wrote:
On 07/04/2021 22:12, Robin wrote:
On 07/04/2021 21:46, Fredxx wrote:
On 07/04/2021 21:42, ARW wrote:
Am I correct in saying that it does not matter if there is a LN
reversal on the input?

It will always have a correct +/- DC voltage.

The DC voltage across the capacitor will be the same, the
difference: one way it will be referenced to neutral, ie close to
ground, and the other will have 230V superimposed on the capacitor
terminals.

I'd assumed Adam meant a bridge rectifier as in

https://www.electronics-tutorials.ws...?fit=331%2C191


but I am prone to be wrong

I saw "full wave rectifier" and thought "single diode". My bad, I
should try reading a little harder.

In which case L-N reversal will make no difference.

Your link is spot on.

And the reason I posted is because I found a LN reversal on a socket
during a EICR.

The tenant was adamant a rectifier would not work.

I was convinced it would (even after a bottle wine of when I posted).

So I asked the collective wisdom of you fine posters.

He clearly doesn't understand what AC stands for, and/or what a
rectifier does.


He was an A level physics teacher which probably made me think he might
have had some understanding of the subject.


If you want to understand something, you have the option of
lashing something together in LTSpice. It's a kind of
physics teacher too. LTSpice was offered by Linear Technology
(makers of op amps and the like).

https://electronics.stackexchange.co...ter-short-time

Getting proper models of things, is a challenge. "Ideal"
models can be used for the deck in the example, but they might
not reproduce every behavior you might want. But if, as in
that example, you wanted to see ripple versus load, you can
get some idea what it would look like.

Paul

In article ,
ARW wrote:
He was an A level physics teacher which probably made me think he might
have had some understanding of the subject.

My brother has a physics degree. Although he taught maths as a career.
Electrics, house or car, are not his thing.

--
*Beware - animal lover - brakes for pussy*

Dave Plowman London SW
To e-mail, change noise into sound.