Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it up?

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or does
this only become a problem in higher voltage/load applications?

Thanks

Phil

In article ,
"TheScullster" writes:
Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it up?

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or does
this only become a problem in higher voltage/load applications?

No problem provided the load is very much less than the cable's
current carrying capacity.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 06/07/2012 15:04, Andrew Gabriel wrote:
In article ,
"TheScullster" writes:
Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it up?

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or does
this only become a problem in higher voltage/load applications?

No problem provided the load is very much less than the cable's
current carrying capacity.


I would say as long as the hottest part of the cable is not too hot to
touch then all should be ok.

Fredxx spake thus:

On 06/07/2012 15:04, Andrew Gabriel wrote:
In article ,
"TheScullster" writes:
Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it
up?

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or
does this only become a problem in higher voltage/load applications?

No problem provided the load is very much less than the cable's current
carrying capacity.


I would say as long as the hottest part of the cable is not too hot to
touch then all should be ok.

And if it does get hot point the fan at it :-P

I keep meaning to post this - 'the proper way to coil a cable'

http://www.youtube.com/watch?v=lLwwB29uQRg

slightly OT, but useful nevertheless.

I first learned this at around age eleven; magicians coil their ropes
in this way so they don't get tangled.

Cheers
J^n

The load is the key really. If its a minimal load I'd not expect much
problems, indeed it might be a bit of a suppressor!

Brian

--
--
From the sofa of Brian Gaff -

Blind user, so no pictures please!
"TheScullster" wrote in message
...
Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it up?

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or does
this only become a problem in higher voltage/load applications?

Thanks

Phil

On Jul 6, 3:03*pm, "TheScullster" wrote:
Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it up?

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or does
this only become a problem in higher voltage/load applications?

Thanks

Phil


Flexible cables are rated much higher current capacity than say T&E.
This is because they are assumed to be in cool situations.
But you must always uncoil them before running near to capacity or
they can melt. Only takes a few minutes too.

Fredxx wrote:

On 06/07/2012 15:04, Andrew Gabriel wrote:
In article ,
"TheScullster" writes:
Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it
up?

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or does
this only become a problem in higher voltage/load applications?

No problem provided the load is very much less than the cable's
current carrying capacity.


I would say as long as the hottest part of the cable is not too hot to
touch then all should be ok.

Overheating in coiled flex is nearly all down to resistive heating and the
ability of the heat to escape. The times I have seen major overheating were
half of a large extension lead left on the reel which means:

a) Centre turns cannot convect due to being against the reel sides and
buried turns are protected from cooling by convection by neighbouring turns
of flex.

b) There are thus several layers of buried turns all unable to lose heat
efficiently and all contributing a small amount of heat, the sum of which is
significant.


The fundamental criterion is that normal PVC cable needs to run at 70C or
less. Try the proposed configuration, leave for an hour and feel - if it's
virtually stone cold, or only slightly warm it will be fine - but you would
want loosen the tie wraps and feel the inner layers.

Hanging such a coil off a hook would be better than leaving it lying on the
floor especially if it could get buried under papers/clothing etc.




--
Tim Watts

On 06/07/2012 15:03, TheScullster wrote:
Hi all

Is there a problem with coiling in-use flex/cable and tie wrapping it up?

Sometimes....

I am talking about 5A fan feed not high load stuff.
Does this induce eddie currents or magnetic fields or something, or does

It does...

this only become a problem in higher voltage/load applications?

Generally ;-)

Leads wound up will find it harder to cool, so running them at higher
currents can cause them to overheat. Small loads ought to be fine,
however it is worth noting that if you really mean a 5A fan, that is not
a particularly small load (1.2kW fan!). Also is that 5A total, or just
5A real current? (Some big blowers will use induction motors with
relatively poor power factors - so the actual current in the wire (i.e.
real + reactive) may be significant, even if only half of it is actually
doing real work.

If you mean a desktop fan protected with a 5A fuse, then it will be fine...

--
Cheers,

John.

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

jkn wrote:
I keep meaning to post this - 'the proper way to coil a cable'

http://www.youtube.com/watch?v=lLwwB29uQRg

slightly OT, but useful nevertheless.

I first learned this at around age eleven; magicians coil their ropes
in this way so they don't get tangled.

Cheers
J^n
Much simpler is to coil it over your elbow and hand but reverse the
direction every three turns. I learnt that at age 11.

Bill

On Jul 7, 4:39*am, Bill Wright wrote:
jkn wrote:
I keep meaning to post this - 'the proper way to coil a cable'

* *http://www.youtube.com/watch?v=lLwwB29uQRg

slightly OT, but useful nevertheless.

I first learned this at around age eleven; magicians coil their ropes
in this way so they don't get tangled.

* * Cheers
* * J^n

Much simpler is to coil it over your elbow and hand but reverse the
direction every three turns. I learnt that at age 11.

Bill


Or "coil" it in a figure of eight prevents twisting.

"Bill Wright" wrote in message
...
jkn wrote:
I keep meaning to post this - 'the proper way to coil a cable'

http://www.youtube.com/watch?v=lLwwB29uQRg

slightly OT, but useful nevertheless.

I first learned this at around age eleven; magicians coil their ropes
in this way so they don't get tangled.

Cheers
J^n
Much simpler is to coil it over your elbow and hand but reverse the
direction every three turns. I learnt that at age 11.

Ah, this needs a clip on youtube, Bill.
Elbow and hand yes but reverse every 3? Pffffffff, sounds complicated.
Anything like coiling a bandsaw blade?

On Jul 7, 9:18*am, "brass monkey" wrote:
"Bill Wright" wrote in message

...

jkn wrote:
I keep meaning to post this - 'the proper way to coil a cable'

* *http://www.youtube.com/watch?v=lLwwB29uQRg

slightly OT, but useful nevertheless.

I first learned this at around age eleven; magicians coil their ropes
in this way so they don't get tangled.

* * Cheers
* * J^n
Much simpler is to coil it over your elbow and hand but reverse the
direction every three turns. I learnt that at age 11.

Ah, this needs a clip on youtube, Bill.
Elbow and hand yes but reverse every 3? Pffffffff, sounds complicated.
Anything like coiling a bandsaw blade?


I'd forgotten, but yes, you can also do it over your hand and elbow.
If you reverse each turn it's the same as the method shown. I tend not
to to it that way because the resulting loop is not always the
diameter I want.

If you 'grok' the method shown on YT then it's easy to understand how
to do the elbow-hand version.

J^n

On Sat, 07 Jul 2012 04:39:14 +0100, Bill Wright
wrote:

jkn wrote:
I keep meaning to post this - 'the proper way to coil a cable'

http://www.youtube.com/watch?v=lLwwB29uQRg

slightly OT, but useful nevertheless.

I first learned this at around age eleven; magicians coil their ropes
in this way so they don't get tangled.

Cheers
J^n
Much simpler is to coil it over your elbow and hand but reverse the
direction every three turns. I learnt that at age 11.

Bill

I always change hands after 99

--
Graham.
%Profound_observation%