The document discusses the three types (A, B, C) of LED tubes used for retrofitting fluorescent fixtures. Type A operates off the existing ballast but is inefficient and dependent on ballast lifespan. Type B bypasses the ballast but requires rewiring which exposes installers to electrical shock. Type C uses an external driver but still has heat issues and high costs. The document recommends for retrofitting, it is best to use LED strips or plates as used in new LED fixtures, not LED tubes, to avoid the problems with all three types.

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November 2015
The Three Types of LED Tubes or TLEDs or T8 LED Tubes
There have been more lighting recalls since January 2015, than in the previous 65
years combined. The vast, vast majority of those recalls have been TLEDs, LED Tubes or
T8 LED Tubes and the recalls have been from some of the largest lighting companies in
the world including but not limited to CREE and Oshram/Sylvania. These major
companies have done the right thing in the face of major financial consequences from
the recalls. What about all the smaller companies and off-shore companies that are
not recalling their Led Tubes (because they can’t afford those financial consequences)
that should. How much liability is being left in the marketplace?
Comment recently (fall of 2015) from a top executive for one of the three largest
lighting companies in the world; “TLEDs are a blight on the lighting industry”.
Type A or (Class A) operates off the existing ballast in the existing fixture and has an internal driver. This
is extremely inefficient and comes with various limitations. Type A is not only dependent on the design
life of the tube (which vary significantly) but is also dependent on the linear fluorescent ballast life in the
existing fixture which not only results in additional maintenance cost but also sacrifices efficiency due to
the additional power loss from the existing ballast and is limited in dimming and controllability.
Additionally all LED Tubes do not work with all existing ballast and may require that they are re-ballasted
with a compatible ballast.
Comments:
Type A or (Class A):
 This class has been dropped by a lot of major Utility Companies because of their poor
performance from operating off the existing ballast. It is difficult to predict how the tube will
perform based on the type of existing ballast and requires the ballast often to be replaced
initially. Also requires that the ballast continue to be replaced through maintenance.
 TLED manufacturers descried in their own installation documents: “Risk of fire and electrical
shock”.
 This class CAN NOT be used with “insta-start ballast” and/or “shunted bi-pin lampholders”
(tombstones). And requires the ballast and lampholders be replaced.

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 Not grounded or potted. No way to discharge power surges. Offers no suppression.
 Poor or non-functional with dimming and controls
 The heat snyc on the top of the tube distributes the heat being created from the internal
components of the tube, across the top of the tube but that heat is then captured inside the
fixture, as the heat sync is not in contact with the housing itself. That heat is then re-directed
back toward the tube and basically cooks the electronics within the tube.
Type B or (Class B) also operates with an internal driver but is designed to be powered directly from the
main voltage supplied to the existing fixture bypassing the existing ballast. This requires an electrical
modification of the existing fixture in order to connect the tube to the power supply. This requires that
the sockets are replaced and a connection is required from the fixture input wires directly to the
sockets. Again as with Type A, Type B is similarly limited in dimming and control capabilities. It is also
important to note that with Type B the fixture’s incoming power wires are connected directly to the
sockets meaning installers and maintenance personal are potentially exposed to the main voltage (120v
or 277v) during installation and maintenance.
Comments:
Type B or (Class B):
 TLED Manufactures describe in their own installation documents: “Risk of fire and electrical
shock”.
 Recently described by GE in a “white paper” as “NOT RECOMMENDED”.
 This class requires that the existing ballast is bypassed (eliminated) and the power hotwired to
the lampholders (tombstones).
 Per UL and most major manufactures: Installation of Type (Class) B TLEDs should not be done by
maintenance but by a licensed electrician due to the possibility of shock and injury.
 This Type (Class) runs 120v or 277v directly to the lampholders (tombstones) and they are
constant hot:
a) Though the lampholders are rated by UL 2x rule for 600 volts, they are designed for
spikes but not for constant/continuous power. The lampholder industry has
petitioned UL on this issues as they state, the lampholders were not designed for
that purpose.
b) Older or brittle lampholders are at risk to melting and/or catching fire due to the
constant power
c) One of the biggest issues is: with the lampholders charged constantly with 120v or
277v, is when a maintenance person replaces the tube or mistakenly replaces the
LED Tube with a T8 tube, they are exposed to electrical shock and injury.
Additionally that person is usually on a ladder and is exposed to injury from falling
off the ladder due to shock. There are several lawsuits in the country now from
exactly that.
 Legally: integrators, electricians, facilities and Utility Companies are being sued for damage and
or injury occurring from those injuries. It is unclear currently who carries the liability.
 Not grounded or potted. No way to discharge power surges. Offers no suppression.
 The heat snyc on the top of the tube distributes the heat being created from the internal
components of the tube, across the top of the tube but that heat is then captured inside the

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fixture, as the heat sync is not in contact with the housing itself. That heat is then re-directed
back toward the tube and basically cooks the electronics within the tube.
Type C or (Class C) operates off an external driver but like Type A and Type B, Type C involves electrical
modification to the existing fixture and the low voltage outputs of the driver are connected to the
sockets instead of line voltage. Installation of Type C tubes involves removing the existing tubes and
ballast and should involve replacement of the existing sockets. The fixture input wires must be
connected to the LED driver and the driver’s low voltage output wires must then be connected to the
sockets before installing the new LED Tubes.
Comments:
Type C or (Class C):
 There are several different styles of Type C LED Tubes. Some integrate with the existing
tombstones and some are mounted by magnets, while some others require screwing the tubes
into the housings.
 The external ballast overcomes most of the issues that occur with Type A and Type B but there
are still issues of heat snyc with Type C based on the method of installation.
 Traditionally Type C are going to be much more expensive that Types A or Types B.
 There are challenges with lumen production with some of the Type Cs based on the fact that
most are a single driver attached to only two tubes and those two tubes are usually not enough
lumens to match requirements.
At the end of the day, if you are going to retrofit a fixture to LED, why use any technology other than the
exact same technology that comes in a new LED Fixture. No major Lighting Company manufactures a
“New LED Fixture” with a LED tube installed. Most if not all “New LED Fixtures” come with LED strips (or
plates) attached inside to the housing. If you are going to retrofit…use the exact same technology!