Sean, if I would take care about that system for the next few years, I will
change the cables cross section without any further discussion.
There is no cable able to run with PVC isolation at 90C for a few years
without creating panic around.
If you have more than 60C measured on the cable isolation, perhaps you
should do the same.

best wishes,
Vasile

On Mon, Mar 23, 2015 at 8:32 PM, Sean Breheny <shb7@cornell.edu> wrote:

> Thanks, but I already looked at that paper. It is decent, but since it
> deals with the PVC insulation from one or two vendors I've never heard of=
,
> I'm not sure how widely-applicable it is.
>
> I was hoping that someone here could help me by either:
>
> a) have an example of a product which they designed years ago using PVC
> wire which was run at 90C or so for years and could tell me whether they
> had problems
>
> or
>
> b) could point me to a app note addressing this from a particular wire
> company or even better, point me to an expert who might know how to
> determine this.
>
> The problem I have is that there are already a large number of units
> installed (they are industrial battery chargers) and we want to increase
> the duty cycle from max current for only 2 minutes per 6 minutes to 3
> minutes per 4 minutes to support a new battery type. Both situations keep
> the wire below its max rated temp but the latter causes the peak and
> average temp to be higher than it is presently. The cable vendor is not
> being very helpful with determining whether this will be a problem.
>
> Sean
>
>
>
> On Mon, Mar 23, 2015 at 2:21 PM, embedded systems <piclist9@gmail.com>
> wrote:
>
> > Sean,
> > This one may help ?
> >
> >
> >
> http://www.google.ro/url?sa=3Dt&rct=3Dj&q=3D&esrc=3Ds&source=3Dweb&cd=3D5=
&ved=3D0CDIQFjAE&url=3Dhttp%3A%2F%2Fwww.researchgate.net%2Fprofile%2FMohame=
d_Morsy4%2Fpublication%2F4049794_Thermal_aging_tests_on_XLPE_and_PVC_cable_=
insulation_materials_of_Saudi_Arabia%2Flinks%2F02bfe51030aaf73f5b000000.pdf=
&ei=3DiVgQVczfL4e7UajBg7gK&usg=3DAFQjCNHqNj41Y5DKS9S0pcbrOPJ4B-3ZUw&sig2=3D=
mwnHotCVoVMTCNNVFp5Kug&bvm=3Dbv.88528373,d.d24
> >
> > On Mon, Mar 23, 2015 at 7:35 PM, Sean Breheny <shb7@cornell.edu> wrote:
> >
> > > Hi all,
> > >
> > > I am looking at an application where 105C rated PVC insulated wire ma=
y
> > > spend several years at 90C. I am trying to find information on whethe=
r
> > this
> > > is feasible (i.e., whether the insulation will still be intact with
> > > reliable mechanical and electrical properties like flexibility). My
> > initial
> > > searches seem to indicate that this is an active research area, which
> is
> > > surprising given that there are surely quite a few power supplies out
> > there
> > > which run hot and have PVC wire so it would seem like it would be
> fairly
> > > easy to gather data from the real world.
> > >
> > > Any pointers?
> > >
> > > Thanks,
> > >
> > > Sean
> > > --
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