Nelson Heat Trace LT Application Information

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
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.
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.
+ 2 hidden pages