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NELSON™ TYPE LT
SELF-REGULATING HEATER CABLE
LT10-CB
LT210-CB
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
Catalog
Service
Maximum
Maximum
Temperature
Maximum
Exposure
T-Rating*
LT3
120
325
150°F (65°C)
185°F (85°C)
T6
LT25
240
540
150°F (65°C)
185°F (85°C)
T6
LT8
120
210
150°F (65°C)
185°F (85°C)
T5
LT210
240
360
150°F (65°C)
185°F (85°C)
T5
Max. Length (Feet) Vs. Circuit Breaker Siz e
Start-Up
120 Volt
240 Volt
Watts/Ft.
Temp.
15A
20A
30A
40A
15A
20A
30A
40A
3
50°F
(10°C)
325 650
0°F
(-18°C)
230
305
325 460
620
650
-20°F
(-29°C)
205
275
325 410
550
650
5
50°F
(10°C)
225
270
460
540
0°F
(-18°C)
155
205
270 310
415
540
-20°F
(-29°C)
135
180
270 275
370
540
8
50°F
(10°C)
145
195
210 295
390
420
0°F
(-18°C)
100
130
195
210
200
265
395
420
-20°F
(-29°C)
90
115
175
210
175
235
350
420
10
50°F
(10°C)
115
150
180 230
305
360
0°F
(-18°C)
85
110
155
180
165
220
325
360 -20°F
(-29°C)
75
100
145
180
150
195
290
360
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.
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NELSON™ TYPE LT
TEMPERATURE DEGREES F (C)
LT23 LT25 LT28 LT210
PIPE TEMPERATURE °F CONVERSION TO °C = 5/9 (°F - 32)
SELF-REGULATING HEATER CABLE
Power Output Rating:
SPECIFICATION/APPLICATION
INFORMATION
(-1) (10) (21) (32) (43) (54) (65)
A LT3 B LT5 C LT8 D LT10
WATTS PER FOOT x 3.28 = WATTS PER METER
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Catalog Numbers:
Standard Feature Suffix:
Voltage Adjustment:
Nelson Heat Tracing Systems products are supplied with a lim it ed warranty. Compl ete Terms and Conditi ons may be found on Nelson's website at
NELSON HEAT TRACING SYSTEMS • P.O. BOX 726 • TULSA, OK 74101 • 918-627-5530 • FAX 918-641-7336 • www.nelsonheaters.com 316-SA-001
Approvals:
ADJUSTMENT MULTIPLIER
208 VAC
220 VAC
277 VAC
Absolute
Product
Power
Length
Power
Length
Power
Length
Max Length
LT23
.76
.93
.85
.96
1.27
1.07
650 ft.
LT25
.79
.93
.87
.96
1.24
1.07
540 ft.
LT28
.84
.93
.90
.96
1.19
1.08
420 ft.
LT210
.86
.93
.92
.96
1.16
1.09
360 ft.
BASIC CATALOG NUMBERS
Voltage
Watts Per Foot
3 5 8
10
120 VAC
LT3
LT5
LT8
LT10
240 VAC
NELSON™ TYPE LT
SELF-REGULATING HEATER CABLE
-CB Tinned Copper Braid
Optional Features Suff ix:
LT23 LT25 LT28 LT210
Use of Self-Regulating heater produc ts at other than rat ed voltages require minor adjustments in power and maximum circuit lengths.
-J Tinned Copper Braid and Fluoropolymer Overjacket
-JT Tinned Copper Braid and Modified Polyolefin Overjacket
D1- Division 1 approved
SPECIFICATION/APPLICATION
INFORMATION
FM CSA UL
Ordinary Locations - Ordinary Locations - Ordinary Locations -
(-CB, -J or -JT options) (-CB, -J or -JT options) (-CB, -J or -JT options)
Hazardous (Classifi ed ) Hazardous (Classified) Hazardous (Classified)
Locations Locations Locations
(-CB, -J or -JT options) (-CB, -J or -JT options) (-CB, -J or -JT options)
Class I, Division 2; Class I, Division 2 Class I, Division 2;
Groups B, C, D Groups B, C, D Groups A, B, C, D
Class II, Division 2 Class II, Division 2 Class II, Division 2
Groups G Groups E, F, G Groups F, G
Class III, Division 2 Cl a ss III, Division 2 Class III, Division 2
(-J option) (-J opti on) (-J opti on)
Class I, Zone 1 Class 1, Division 1 Class I, Zone 1 and 2
Group IIC Groups B, C, D Group IIC
Class II, Division 1 (D1 option)
Groups E, F, G Class I, Division 1
Class I, Zone 1 Groups B, C, D
Group IIB + H2 Class II, Division 1
Zone 1, Ex e II T6 (T5) Groups E, F, G
Cl a ss III
Accessories:
• Connection Kits for Power Connection, Tee Splice, Splices and End Seals (Nelson PLT and ALT Series)
• Thermostatic Controls (Nelson TA, TH, TE and HC Series)
• Junction Boxes, Tapes and Warning Signs
• Custom Control, Monitoring and Power Panels
• Division 1 Connection Kits for Power Connection, Tee Splice, Splice and End Connection (Nelson HASK Series)
• Zone 1 Connection Kits for Power Connection, Tee Splice, Splice and End Connection (Nelson Z1-PLT and Z1-ALT Series)
www.nelsonheaters.com.
© 2011 Nelson Heat Tracing Systems February 2011
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