My impression about the UL standard and mark (or other north american stand=
ards =

for electrical industrial or domestic equipment) is that it is more centere=
d =

around fire hazard than electric shock hazard (compared to european =

counterparts). A 24V device that is not designed correctly could very well =

burst into flames but it still might be perfectly safe concernig electrical =

shock.

This would imply that also 24V devices needs a UL mark. Is this correct? Wh=
ere =

is the lower limits for exemption? I guess it would be an energy or power l=
imit =

rather than just a voltage in this case.

/Ruben

> On Fri, Oct 31, 2008 at 6:44 AM, alan smith <micro_eng2@yahoo.com> wrote:
> > Low voltage...lower than 48V?? So my device that runs on 24VDC
> > wouldnt have to be UL certified..based on the fact my external supply
> > IS certified.
> =

> Not true. It depends on the device type and your external power supply.
> It also depends on the customer.
> =

> Again, I am using UL508 as an example, it examines not only
> the electrical part, but also the enclosure/construction. If your device
> is falling under UL508 and is using an external Class 2 power supply
> (Class 2 is the keyword here), the electrical examination will be quite
> simple. But still there will be examinations/tests involved if the custom=
er
> wants UL listed mark.
> =

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
Ruben J=F6nsson
AB Liros Electronic
Box 9124, 200 39 Malm=F6, Sweden
TEL INT +46 40142078
FAX INT +46 40947388
ruben@pp.sbbs.se
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

-- =

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