Moulded mains plug failure

B

bruce varley

Guest
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA
 
bruce varley wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA
Click to expand...
The wires have broken, a fairly common problem on moulded plugs.
 
"bruce varley"


( snip whole pile of putrid, whining,ridiculous shite )


** Replace the DAMN plug !!!

Wanker.





........ Phil
 
Phil Allison wrote:

"bruce varley"

( snip whole pile of putrid, whining,ridiculous shite )

** Replace the DAMN plug !!!

Wanker.

....... Phil
Click to expand...
That time of the month again already Phyllis ?
 
bruce varley wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA
If you are really interested perform surgery and cut the rubber off with
Click to expand...
a stout knife and investigate if there is something strange tell us
 
"David L. Jones" <altzone@gmail.com> wrote in message
news:6f921c42-9c05-4de1-ae1d-01184e0f3547@r36g2000prf.googlegroups.com...
On Dec 29, 11:23 pm, bruce varley <bxvar...@weastnet.com.au> wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA

That's a common problem, the wires have simply broken through fatigue,
there is almost certainly no protection device in the plug. Just
replace the plug.
But personally I wouldn't bother, bin it and get a proper temperature
controlled station.

Dave.
Click to expand...
....and AFAIK, you should NEVER, under any conditions, have less than close
to zero ohms continuity between an earth pin and the frame of an
appliance...
 
On Dec 29, 11:23 pm, bruce varley <bxvar...@weastnet.com.au> wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA
Click to expand...
That's a common problem, the wires have simply broken through fatigue,
there is almost certainly no protection device in the plug. Just
replace the plug.
But personally I wouldn't bother, bin it and get a proper temperature
controlled station.

Dave.
 
MoiInAust wrote:
"David L. Jones" <altzone@gmail.com> wrote in message
news:6f921c42-9c05-4de1-ae1d-01184e0f3547@r36g2000prf.googlegroups.com...
On Dec 29, 11:23 pm, bruce varley <bxvar...@weastnet.com.au> wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA
That's a common problem, the wires have simply broken through fatigue,
there is almost certainly no protection device in the plug. Just
replace the plug.
But personally I wouldn't bother, bin it and get a proper temperature
controlled station.

Dave.

...and AFAIK, you should NEVER, under any conditions, have less than close
to zero ohms continuity between an earth pin and the frame of an
appliance...
Click to expand...
But you should get less than one ohm if you measure between the earth
and neutral in a GPO socket.
 
On Dec 29, 11:23 pm, bruce varley <bxvar...@weastnet.com.au> wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA
Click to expand...

In the early days, it was common to cut off ANY moulded plug (from
new) and replace it with a standard
aftermarket plug, there were that many failures. One I remember was a
70's vintage Hanimex fluorescent desk lamp where moving the cord
around near the plug caused the light to go on and off.

Other problems with moulded plugs from that era is the cord outer
sheath coming free from where its attatched to the entrance to the
plug, exposing the coloured wires inside. While the plug will still
work, its not very safe.

The few moulded plugs I managed to hack apart years ago typically used
spot welding or direct crimping to the pin to make the electrical
connection. Obviously it isn't good enough in some cases.
 
On Mon, 29 Dec 2008 07:23:48 -0600, bruce varley
<bxvarley@weastnet.com.au> put finger to keyboard and composed:

Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA
Click to expand...
AFAIK British mains plugs (not the moulded type) protect the active
wire with a user replaceable fuse. I doubt that your plug is anything
out of the ordinary.

I've had to replace the mains cable on my old Micron temperature
controlled soldering station twice, but then I'm in the habit of
packing my iron away after each use. Both times the break was at the
iron end. BTW, I've since dropped the hand-piece and fractured the
ceramic element inside, so if anyone needs the unit (cat # T2441, 60W)
for spares, they are welcome to it.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
"David L. Jones" wrote:

On Dec 29, 11:23 pm, bruce varley <bxvar...@weastnet.com.au> wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA

That's a common problem, the wires have simply broken through fatigue,
there is almost certainly no protection device in the plug. Just
replace the plug.
But personally I wouldn't bother, bin it and get a proper temperature
controlled station.
Click to expand...
I think the point he was getting at was the the earth could fail first, and
you'd be blissfully unaware of it until the fatal shock.

Hence ELCBs / RCCDs should be mandatory in ALL installations.

Graham
 
Davo wrote:

But you should get less than one ohm if you measure between the earth
and neutral in a GPO socket.
Click to expand...
Eh ? What has that got to do with the price of fish ?

Graham
 
kreed wrote:

On Dec 29, 11:23 pm, bruce varley <bxvar...@weastnet.com.au> wrote:
Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA

In the early days, it was common to cut off ANY moulded plug (from
new) and replace it with a standard
aftermarket plug, there were that many failures. One I remember was a
70's vintage Hanimex fluorescent desk lamp where moving the cord
around near the plug caused the light to go on and off.

Other problems with moulded plugs from that era is the cord outer
sheath coming free from where its attatched to the entrance to the
plug, exposing the coloured wires inside. While the plug will still
work, its not very safe.

The few moulded plugs I managed to hack apart years ago typically used
spot welding or direct crimping to the pin to make the electrical
connection. Obviously it isn't good enough in some cases.
Click to expand...
I bought an inexpensive but decent looking 4 way extension lead from a local
supermarket some years ago.

It didn't 'feel right'. I examined it and no, it wasn't welded but used
standard screw down connections made by cheap Chinese workers.

The thing that 'didn't feel right' was a single strand of copper wire attached
to the live connection of one of the outlets that had 'missed the hole'. I
corrected it.

Heads you lose, tails you lose.

Graham
 
Franc Zabkar wrote:

On Mon, 29 Dec 2008 07:23:48 -0600, bruce varley
bxvarley@weastnet.com.au> put finger to keyboard and composed:

Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA

AFAIK British mains plugs (not the moulded type) protect the active
wire with a user replaceable fuse. I doubt that your plug is anything
out of the ordinary.
Click to expand...
The moulded type also have fuses inserted from the 'bottom face'.
http://en.wikipedia.org/wiki/File:Bs1363-plug.jpg

However I did once find ONE with no visible fuse. Maybe it was internal and
'one-shot' ?

It's great to have the safest electrical system in the world !

Graham
 
Eeyore wrote:
I bought an inexpensive but decent looking 4 way extension lead from a local
supermarket some years ago.

It didn't 'feel right'. I examined it and no, it wasn't welded but used
standard screw down connections made by cheap Chinese workers.
Click to expand...

As opposed to shoddy British labor?


The thing that 'didn't feel right' was a single strand of copper wire attached
to the live connection of one of the outlets that had 'missed the hole'. I
corrected it.

Heads you lose, tails you lose.

Graham
Click to expand...

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The first sign of insanity is denying that you're crazy.
 
Eeyore wrote:
Franc Zabkar wrote:

On Mon, 29 Dec 2008 07:23:48 -0600, bruce varley
bxvarley@weastnet.com.au> put finger to keyboard and composed:

Hi, I've got a vintage Scope soldering iron, direct 240V connection (no
transformer, the cord goes straight into the iron). It dates from early
80s IIRC, and has given faithful service over all this time. No model
number marked so I can't provide it here, it has a red handle. Recently
it stopped working, to my surprise the problem was at the plug end of the
cord, not the iron end. The element resistance is fine, and the element
to shaft resistance is off the scale (haven't meggered it).

The mains plug is moulded and sealed. For all 3 leads including earth,
the resistance from the plug pin to the associated lead is erratic,
varying from many K to many megs. Might there be some sort of protective
device built into the plug, such as fusing? Strange though that the earth
wire continuity has gone. All in all it sounds like a straight age
failure, just wonder if there's something else there that I should be
aware of. Any suggestions on possibilities? TIA

AFAIK British mains plugs (not the moulded type) protect the active
wire with a user replaceable fuse. I doubt that your plug is anything
out of the ordinary.

The moulded type also have fuses inserted from the 'bottom face'.
http://en.wikipedia.org/wiki/File:Bs1363-plug.jpg

However I did once find ONE with no visible fuse. Maybe it was internal and
'one-shot' ?

It's great to have the safest electrical system in the world !
Click to expand...

The safest system is the one that was never built.



--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
"Michael A. Terrell" wrote:

As opposed to shoddy British labor?
Click to expand...
Learn to spell shoddy USA labour right (as used in Detroit).

http://www.avolites.org.uk/jokes/queen.htm

You guys just fucked your own country ! Bwahahahahahahahaaaa !


Graham
 
"Michael A. Terrell" wrote:

The safest system is the one that was never built.
Click to expand...
I'm sure you could contribute very positively to that.

Graham
 
Eeyore wrote:
"Michael A. Terrell" wrote:

The safest system is the one that was never built.

I'm sure you could contribute very positively to that.
Click to expand...

Certainly. Anyone could. by following any of your rejected designs.


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http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
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