Water heater wiring?
Mark
I've got hot water tank that has an economy 7 (night time) heater. But it
keeps burning the insulation on the live (blue) wire. When I rewire it'll
work fine before the insulation burns again and disconnects the wire.
Have I faulty wiring or a faulty heater?
Harry Bloomfield
It sounds most likely to be a poor and high resistance connection, the
connection to which the blue is connected. Blue is (or should be)
nuetral not live BTW.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org
Greg
>nuetral not live BTW.
>
Depends on which side of the Atlantic you are on.
phil-new...@ipal.net
That depends on where the heat causing the burning is coming from. If it
is coming from the heater's heating elements, the heater is at fault for
not protecting the wiring. If it is coming from the wire itself, then it
could be either the wire (such as it has been damaged and has a hot spot)
or the heater (it's drawing too much current and overheating the wire).
In the latter case, your breaker should be tripping, too, which means it
is either faulty or incorrectly sized. If you are putting in all new wire
each time, that sounds like an overcurrent situation, unless you are using
the wrong wire size.
Tell us more. What is your supply voltage, heater current, breaker rating,
and wire gauge?
--
-----------------------------------------------------------------------------
| Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
| (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
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phil-new...@ipal.net
So I see you have a UK callsign. So what are the wiring color standards
over there? You say neutral is blue? What are the hot colors (up to 3
for 3 phase power)?
Fads
Fads
"Greg" <gfre...@aol.com> wrote in message
news:20040223115702...@mb-m29.aol.com...
Harry Bloomfield
Economy 7 indicates UK :-)
Michael Moroney
>So I see you have a UK callsign. So what are the wiring color standards
>over there? You say neutral is blue? What are the hot colors (up to 3
>for 3 phase power)?
Neutral is blue over there, hot (single phase) is brown. I believe 3
phase hots are brown, black & grey.
--
-Mike
phil-new...@ipal.net
And what about (safety) ground?
Do you know if the rest of Europe is the same?
phil-new...@ipal.net
OK, now that I know what colors the wires should be over there, tell me
what colors are actually present on the wiring. The other wire is brown?
I'm assuming 1 phase power. If both wire gauges are the same, then what
is most interesting here is that the other wire is not burning up. Since
blue is supposed to be neutral, but you are saying "live", I'm wondering
if it's wired backwards, and is drawing extra current because it has the
terminal for the blue wire connected to the water piping or other ground,
and is losing current to that. If this were the case your breaker should
still be tripping off if it is connected on the blue side, but that would
not normally be the case.
Another possibility is that some other power source is energizing the water
piping and it's coming back into the water heater which has connected it to
the blue wire. If the wiring is connected but the heater is shut off, do
you still get the blue wire burning up?
There are other tests that are more dangerous, so I'll just say you need to
get a professional electrician to look into it if some simple problem is
not found.
Michael Moroney
>On Mon, 23 Feb 2004 19:44:22 +0000 (UTC) Michael Moroney <mor...@world.std.spaamtrap.com> wrote:
>| phil-new...@ipal.net writes:
>|
>|>So I see you have a UK callsign. So what are the wiring color standards
>|>over there? You say neutral is blue? What are the hot colors (up to 3
>|>for 3 phase power)?
>|
>| Neutral is blue over there, hot (single phase) is brown. I believe 3
>| phase hots are brown, black & grey.
>And what about (safety) ground?
It's either green or green with a yellow stripe.
>Do you know if the rest of Europe is the same?
This is a newish standard, at least for some countries. I believe all of
Europe uses this for new stuff but old stuff in some countries is
different.
England may have used blue for a hot for the old standard, leading to a
lot of confusion! (One European country did, anyway) So the original post
may be talking about a hot, not a neutral.
--
-Mike
Harry Bloomfield
> Neutral is blue over there, hot (single phase) is brown. I believe 3
> phase hots are brown, black & grey.
On flexible cables....
Blue = Nuetral
Brown = Live
Green/yellow = Earth or ground
On non-flexible cable...
Black = Nuetral
Red = Live (single phase)
On three phase.. Red, Yellow, Blue
Mark
my haste to fix the problem I typed it and didn't check afterwards.
The wiring and the element has been fine for 15 years.
I've just reconnected it again and will check in a few days to what it's
like. It never blows the fuse.
Mark
pablito
"Mark" <we...@hotmail.com> wrote in message
news:c1f0kh$1gqdco$1...@ID-27793.news.uni-berlin.de...
Good Morning Mark,
You may have a short between the heater element
and Ground on the neutral side, which may be providing a
ground path for some other device on your overall wiring
layout, or, possibly the heater is not grounded, and
there is return to ground path for something else back
through the water heater circuit.
I have seen this in the past when the ground on the main
panel was bad, but the ground through the water pipes
was good, and all the neutral currents went through the
path of least resistance back to ground, the hot water
heater wiring.
Sneak ground paths, and overloaded neutrals are hard
to find, and a very common problem, especially on older wiring systems.
Check this with an Ohmeter, ( with the heater element
disconnected, ) read between the neutral side, ( Blue )
wire and Ground. If you find a short, ( unless the Neutral
is grounded deliberatly at this point ) This is your problem.
But you have another problem that you are not seeing,
and that the Neutral return to ground either at your
main sevice panel, or at your meter is open.
This must be a very small hot water heater, as all
heaters I am used to are 240vac, not 120vac..
Have a great day .
phil-new...@ipal.net
If current is flowing only on the neutral (from somewhere else), then of
course the fuse on the hot won't blow.
The "somewhere else" could be something else that has a broken neutral but
is well grounded to the water than the heater is grounded do, where the
water ground doesn't have a good path back to the transformer ground.
There could be other causes, but the dangerous ones come to me first.
phil-new...@ipal.net
| This must be a very small hot water heater, as all
| heaters I am used to are 240vac, not 120vac..
He's in UK. Single phase, single pole, 220-240 some volts. They won't
get the problem of phases out of balance with an open neutral like we
would in the US (and can thus see something is wrong sooner), but it can
still happen in various forms, which seems very plausible for this.
daestrom
"Harry Bloomfield" <harry.m1...@tiscali.co.uk> wrote in message
news:mesnews.bc3c7d42....@tiscali.co.uk...
> On 23/02/2004 Greg a wrote :
> >> Blue is (or should be)
> >> nuetral not live BTW.
> >>
> >
> > Depends on which side of the Atlantic you are on.
>
> Economy 7 indicates UK :-)
Perhaps, but the capital 'UK' on the first line certainly does :-)
daestrom
Peter O
relatively poor cable connection (which with a little oxidation due to heat
causes higher than normal resistance & further heat ) & ppssibly also a high
power thermal heating element,
Remedies include better connection, tinned bigger cable witrh higher thermal
rating of insulation, & lower wattage element.
I have had similar problems with everything apparently "within spec", my
burnouts developed about six month intervals.
Pete
"Mark" <we...@hotmail.com> wrote in message
news:c1cqks$1gpcg3$1...@ID-27793.news.uni-berlin.de...