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NELSON™ TYPE LT
SELF-REGULATING HEATER CABLE
Options: (Delete -CB and add)
SPECIFICATION/APPLICATION
INFORMATION
• Optional Overjacket
• Standard Metal Braid
• Stranded Plated Copper Conductors
• Self-Regulating Conductive
• Bonded Inner Thermoplastic Jacket
• Outer Thermoplastic Elastomer Jacket
LT3-CB
LT5-CB
LT8-CB
LT23-CB
LT25-CB
LT28-CB
Description:
Nelson Type LT self-regulating heater
cable is a parallel circuit electric heater strip. An
irradiation cross-linked conductive polymer core
materia l is extrud ed over the mu lti-stranded, tinplated, 16-gauge copper bus wires. The
conductive core material increases or
decreases its heat output in response
to temperature changes. Two jackets provide
extra dielectric strength, moisture resistance, and
protection from impact and abrasion damage.
The inner thermoplastic jacket is extruded over
and bonded to the core material. A thermoplastic
elastomer outer jacket is then extruded over the
inner jacket.
A stranded tinned copper metal braid is
supplied on all heat ers. An optional overj acket
(fluoropolymer or modified polyolefin) can be
specified when the heater cable is to be inst alled
in wet or corrosive environments.
Principle of Operation:
The parallel bus wires apply voltage
along the entire length of the heater cable. The
conductive core provides an infinite number of
parallel conductive paths permitting the cable
to be cut to any length in the field with no dead
or cold zones developing. The heater cable
derives its self-regulating characteristic from
the inherent properties of the conductive core
materia l. As the core
Application:
Nelson's Type LT self-regulating heater
cable is ideal for use in maintaining fluid flow
under low ambient conditions. Freeze protection
and low watt density process temperature
systems s uch as produc t pipelines, fire protection,
process water, dust suppression systems, lube
oil, condensate return, hot water and structure
anti-icing are typical applications for this product.
The base product is supplied with a tinned
copper metal braid that may be used in both
general applications and in dry, non-corrosive
hazardous (classified) areas. It is also used to
provide a conductive ground path when cable is
installed on non-conductive surfaces, such as
plastic or painted pipe.
material temperature increases, the number of
conductive paths i n the core material decrease,
automatically decreasing the heat output. As the
temperature decreases, the number of
conductive paths i ncrease, causing the heat
output to increase. This occurs at every point
along the length of the cable, adjusting the power
output to the varying conditions along the pipe.
-JT A tinned copper metal braid with a
modified polyolefin overjacket is
available for use when the heater cable
is exposed to aqueous solutions of
inorga nic chemicals (phosph ate, dilut e
acids, chlorides, bases and carbonites).
It is also recommended where
mechanical abuse is a problem.
-J A tinned copper metal braid with a
fluoropolymer overjacket is available for
use when the heater is availabl e for
use when the heater cable is exposed
to excessive moisture, organic
chemicals, solvents, etc. in hazardous
(classified) areas and ordinary areas.
The self-regulating effect allows the cable
to be overlapped without creating hot spots or
burnout. As the cable self-regulates its heat
output, it provides for the efficient use of
electric power, producing heat only when and
where it is needed, and also limiting the
maximum sheath temperature.
D1- Approved for use in Cl ass I, Divis ion 1,
Groups B, C, and D, Class I I , D ivision 1,
Groups E, F and G, Class III hazardous
areas. D1 heating cable requires the use
of HASK series connection kits.
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NELSON™ TYPE LT
Max. Length (Feet) Vs. Circuit Breaker Siz e
NOTES: 1. Circuit breakers are sized per national electrical codes.
SELF-REGULATING HEATER CABLE
SPECIFICATION/APPLICATION
INFORMATION
Performance and Rating Data:
Number
LT23 240 650 150°F (65°C) 185°F (85°C) T6
LT5 120 270 150°F (65°C) 185°F (85°C) T6
LT28 240 420 150°F (65°C) 185°F (85°C) T5
LT10 120 180 150°F (65°C) 185°F (85°C) T5
*Electrical equipment T-rating codes define the maximum surfa ce temperature that equipment will reach. It is used in ha zardous
(classified) area applications.
Voltage
Length
Maintenance
Intermittent
Circuit Breaker Selection:
2. When using 240 volt product at 208, 220 or 277 volts, use the circuit adjustment factors shown in the Voltage
Adjustment Table.
3. When using 2 or more heater cables of different wattage ratings in parallel on a single circuit breaker, use the 15A
column amperage of 15 amps, divide it by the maximum footage to arrive at an amps/foot figure for each cable.
You can then calculate circuit breaker sizes for these combination loads. These amps/foot factors include the
125% sizing factor.
4. National electrical codes require ground-fault equipment protection for each branch circuit supplying electric
heating equipment. Exceptions to this requirement can be found in the 2002 N.E.C.
5. Heater cables with D1 optional construction require the use of ground fault interrupter/ground leakage device with
a trip setting no greater than 30mA.