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Description / Abstract:
This outline of investigation covers LED (light emitting diode)
kits intended for field installation to retrofit signs already
installed in the field and LED kits intended for installation in
new signs.
Retrofit kits
These LED kits are intended to replace all of the electrical
components related to a type of illumination in a sign. For neon
signs these components include neon tubes, tube supports, neon
supplies, and all secondary wiring from the neon supply. For
fluorescent signs these components include fluorescent tubes,
lampholders, ballast, and ballast secondary wiring. All types of
illumination within a sign must be replaced, unless there are
different compartments of a sign for different light sources and
they only share the same circuitry at the branch circuit connection
point.
Retrofit kits include the power supply or transformer, power
supply or transformer enclosure, the LEDs and the LED mounting
means.
New Sign Construction
Component power units may be incomplete with respect to
electrical enclosure, mounting, supply connections, etc.
LEDs, secondary wiring, and LED transformers or supplies may be
provided separately.
Glossary
CLASS 2 CIRCUIT – The wiring, conductors and components
connected only to a Class 2 supply source. See Class 2 Supply
Source, 1.4.2.
CLASS 2 SUPPLY SOURCE – An electrical source, such as a
transformer, power supply, or battery, having an open-circuit
voltage that is less than 30 V rms (42.4 V peak) or 60 V DC and
having limited energy available in the circuit under load
conditions, including short-circuit and extremely low resistance. A
Class 2 supply source can be either inherently limited or
non-inherently limited.
a) INHERENTLY LIMITED SUPPLY SOURCE – A transformer, power
supply or battery having no discrete protective device that is
relied upon to limit the output energy available from the supply. A
power supply or battery with internal current and energy limiting
circuitry shown to be reliable is eligible to be identified as
inherently limited. Transformers, power supplies and batteries may
be provided with protective devices as long as they are not relied
upon to limit the output.
b) NON-INHERENTLY LIMITED SUPPLY SOURCE – A transformer, power
supply or battery having a discrete protective device that
automatically interrupts the output when the current and energy
output reaches a prescribed limit.
CONDITIONS OF USE – Parameters and specifications that identify
the proper use of a component according to the requirements to
which it has been determined to comply, and limitations of the use
of the component in a sign or outline lighting.
DAMP LOCATION – The designation for a component that has been
evaluated generally for use in exterior locations where protected
overhead from rain and snow, or interior locations where subject to
moderate degrees of moisture, primarily by humidity and
condensation. Protected overhead is generally considered to be
within an area formed by an imaginary line drawn from the outer
edge of the eave, overhang, or signbody inward at a 45 degree angle
from vertical. Additionally, the interior of a sign body provided
with a sign face and installed in an outdoor exposed location is a
damp location. Examples include partially protected areas such as
under a canopy, under a roofed porch, or indoors in a car wash away
from a direct water spray.
DRY LOCATION – The designation for a component that has been
evaluated for use in an environment where the component is not
normally subject to dampness or wetness. Examples include inside an
indoor shopping mall, inside a retail store, in an attic or
scuttle, and other similar places.
ELV CIRCUIT – A secondary circuit with limited voltage and
energy that reduces the risk of fire and shock in accordance with
the requirements in the Standard for Information Technology
Equipment, UL 60950.
HAZARDOUS ENERGY LEVEL – A stored energy level of 20 J or more,
or an available continuous power level of 240 VA or more, at a
potential of 2 V or more.
LPS-LIMITED POWER SOURCE – Power supplies identified as
"LPS" or where the output is considered limited
power, are considered equivalent to power supplies with Class 2
outputs.
POLLUTION DEGREES:
a) POLLUTION DEGREE 2 – Normally only non-conductive pollution.
However, temporary conductivity is capable of being caused by
condensation.
b) POLLUTION DEGREE 3 – Conductive pollution, or dry,
non-conductive pollution that becomes conductive due to
condensation.
SAFETY EXTRA-LOW VOLTAGE (SELV) CIRCUIT – A secondary circuit
with limited voltage and energy that reduces the risk of fire and
shock in accordance with the requirements in the Standard for
Information Technology Equipment, UL 60950.
WEATHERPROOF – See Wet Location, 1.4.10.
WET LOCATION – The designation of a component that has been
evaluated for use in a location that is subject to a direct spray
or splashing of water or other liquids. Examples include locations
used for outdoor channel letters and outline lighting or indoors in
a car washing area in a direct water spray.