62 ELECTRICALCONTRACTOR | JUL. 16 | WWW.ECMAG.COM
> FOCUS THE CHALLENGES OF LED UPKEEP
installed lamps and luminaires. For best results, manufacturer
operating guidelines should be followed. If color stability is a
concern, the specifier may attempt to negotiate a product warranty that addresses color shift if one is not available.
Another aspect of product design is whether the product is
easily field-serviceable, which allows component replacement
and possibly upgrades. This makes the product more durable
and brings us to a challenging area of LED lighting maintenance, which is product replacement.
After LED products are installed, infancy failures may occur
and would be covered by warranty. Should a product fail after
the warranty expires, replacement products must be purchased
unless spares are available in attic stock. The look and shape of
LED luminaires are not standardized, and product cycles are
compressing to as little as one to two years, resulting in new
generations. This presents the risk that the manufacturer may
no longer be in business or that the product may no longer be
available or have a different light output or form factor.
Therefore, when purchasing LED luminaires, the specifier
might ask the manufacturer about future availability of inventory and how it is servicing products today that were sold
several years ago.
There is also the question of what the owner will do when
the lighting has failed, which in turn raises the question of what
that even means. When matching a product to an application,
the specifier should not confuse the L value with an exact
replacement point. This value expresses lumen maintenance,
which serves as a guide but not an absolute. The Next Generation Industry Alliance recommends a broader approach based
on the application, defining life as when light output falls by X
percent, color shift rises above Y, Z percentage of LEDs fail, or
some combination of these. The replacement point is, therefore, generally based on light levels (lumen depreciation, some
LEDs failing) or aesthetics (color shift, some LEDs failing when
the light source is visible in the luminaire).
While there have been some industry attempts to provide a
clear end-of-life signal, a majority of products do not. The owner
might benefit from incorporating periodic scheduled inspections as part of its maintenance program. This could include
spot-checking light levels and, for applications with sensitive
aesthetics, visual inspection for outages and color shift. Intelligent lighting control is becoming more popular because it is
inherently compatible with LED lighting. Should the control
system offer monitoring capability, this allows remote monitoring of lighting status, notably whether a given lighting point is
operational. The system may allow remote alarm notifications.
A failing driver may either cause its LEDs to stop producing
light or, less likely, become dim. Should failures occur due to the
driver, being able to replace it in the field could be beneficial
if the light source still has considerable useful life. Again, the
luminaire should be easily field-serviceable for this purpose,
with quick disconnects, though product replacement can be
problematic as there are no current industry standards for
drivers. Therefore, the driver must be replaced with the same
product or one approved by the manufacturer for the given
luminaire. If an unusual number of driver failures are encoun-
tered, it could be manufacturer defect, high driver operating
temperatures or some other cause. Consult the manufacturer.
Some products also allow the field replacement of the
light engine, which can experience similar issues as complete
products and drivers. A light engine would normally need to
be replaced due to catastrophic failure, lumen depreciation or
color shift. In the future, replaceable phosphors may be available. If products are exhibiting premature lumen depreciation,
this may be caused by high operating temperatures, miswiring
that results in the lighting being dimmed by a dimming control,
or some other cause. Again, consult the manufacturer.
Other maintenance practices
LED lighting installations may benefit from other sensible
maintenance practices such as luminaire cleaning and re-aiming. Traditionally, cleaning occurs when the luminaire is
relamped, if at all. As LED luminaires generally do not require
spot relamping, maintenance personnel must make an effort
to ensure cleaning occurs, particularly in environments such
as outdoor applications where dirt accumulation can reduce
light output. Additionally, as displays move, directional lighting
must be re-aimed.
A growing maintenance area in LED lighting is controls,
which are becoming increasingly automatic and sophisticated.
Changes to the space, how the space is used, etc., may result in
the controls falling out of sync. Periodic inspections, including
functional testing of a sampling of control points, will reveal
deficiencies that can be corrected by reorienting or moving sensors and recalibration. Maintenance ensures lighting systems
perform as intended over the long term.
As lighting technology changes, maintenance is changing
with it, though the fundamentals remain the same: relamping, cleaning and troubleshooting. LED lighting significantly
reduces maintenance, while advanced lighting controls are providing new tools that facilitate it. The key to maintaining LED
lighting and control installations is to understand the technology and proactively monitor the systems.
For more information, consult LED and control manufacturers or review IES-RP- 36, Recommended Practice for
Lighting Maintenance, published by the Illuminating Engineering Society in 2015. This publication, which I authored in
conjunction with the IES Lighting Maintenance Committee,
describes recommended maintenance practices for all popular
light sources, including extensive material on LED lighting.
DI LO UIE, L.C., a lighting industry journalist, analyst and marketing
consultant, is principal of ZING Communications. He can be reached
at www.zinginc.com. F L