Nelson Product Guide: Nelson Heat Trace Self-Regulating Heater Cables for Fire Sprinkler Systems Manuals & Guides

SELF-REGULATING HEATING CABLE FOR FIRE SPRINKLER SYSTEMS – Product Guide

THE COMPLETE FREEZE PROTECTION SYSTEM

Nelson self-regulating electric heat trace cables are now listed and certied for freeze protection from main water lines to

sprinkler heads.

Recent NFPA 13 changes have approved self-regulating cables for use with branch sprinkler systems to ensure reliable re suppression

in unheated commercial and industrial facilities.

Nelson freeze protection is inexpensive to run, with virtually no maintenance needed. It also contributes to improved re safety, since

sprinkler systems can respond immediately without the need for antifreeze chemicals.

SELF-REGULATING CABLES

Nelson CLT and LT Series heating cables are available for both 120
and 208-277 Vac applications, with a choice of power densities
to provide freeze protection in ambient temperatures as low as
–40°C (–40°F). These cut-to-length cables can be used in wet or dry
environments. The LT Series is also approved for hazardous locations
when used with appropriate connection kits.

CONNECTION KITS Self-Regulating Cables

A complete selection of connection kits and accessories are available
for spicing cables under pipe insulation or in a rugged NEMA 4X
enclosure for exceptional weather and corrosion resistance.

MONITORING AND CONTROL

Choose from a range of industrial thermostats, cable monitoring
systems and circuit management systems for simple, reliable

operation of any heating cable conguration. Nelson offers ordinary
and hazardous location controls with approvals and certications for

practically any application.

Connection Kits Monitoring and Control

A SIMPLER AND SAFER FREEZE PROTECTION SOLUTION

Nelson freeze protection overcomes the safety shortcomings of other methods.

Nelson’s re protection system is ideally suited for garages,

warehouses, porticos and other unheated commercial or industrial

locations where branch sprinkler systems are used for re protection.

Because the system is always charged with water, there is less risk of
corrosion due to trapped moisture and air.

Electricity costs are minimal because Nelson’s self-regulating cables
and temperature controls apply heat only where and when it is
needed.

APPROVALS

The NFPA 13, 2010 Edition, Standard for the Installation of Sprinkler
Systems allows listed electrical heat tracing to be utilized for freeze
protection of supply lines, standpipes, and branch lines containing
sprinklers.

Nelson CLT and LT Series self-regulating cable systems are approved
to the following standards:

• cCSAus Certied to the IEEE standard . 515.1-2012 in the United

States for supply lines, standpipes, branch lines and sprinkler
heads.

• CAN/CSA C22.2 No. 130-03 in Canada for supply lines,
standpipes, branch lines and sprinkler heads.

• UL Listed for supply lines, standpipes and branch lines not

containing sprinklers.

With dry systems, valves control water ow. As a result, water takes longer
to reach the sprinklers from the source. Nelson products ensure that water
is immediately available at each sprinkler head in the event of a re.

No antifreeze is needed, eliminating the possibility of chemicals leaking into
drains and ground water. If a re does occur, no chemicals are sprayed in
the facility or equipment.

STEP 1: CALCULATING HEAT LOSS REQUIREMENTS

To determine the heat loss that must be replaced by the heating cable,
the following should be determined:

• Tf: Fluid Temperature to be maintained

• Ta: Minimum ambient temperature

• Size of pipe to be heated

• Thermal insulation – type and thickness

TABLE 1: PIPE HEAT LOSS ( WATTS/FT )

Insulation Thickness

mm (in)

25 (1.0)

38 (1.5)

50 (2.0)

63 (2.5)

75 (3.0)

Insulation Thickness

mm (in)

25 (1.0)

38 (1.5)

50 (2.0)

63 (2.5)

75 (3.0)

Note: Multiply heat loss values by 3.28 for Watts/m.

( ΔT ) Pipe Diameter in Inches ( IPS )

°C °F 1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4

18 10 0.3 0.4 0.4 0.5 0.6 0.7 0.8 0.9 1.1
28 50 1.7 1.9 2.2 2.5 2.8 3.3 3.8 4.4 5.4
56 100 3.5 3.9 4.5 5.3 5.8 6.8 7.9 9.2 11.3
83 150 5.4 6.2 7.1 8.3 9.1 10.7 12.4 14.4 17.6
18 10 0.3 0.3 0.4 0.4 0.4 0.5 0.6 0.7 0.8
28 50 1.3 1.5 1.7 1.9 2.1 2.5 2.8 3.2 3.9
56 100 2.8 3.1 3.5 4.1 4.4 5.1 5.9 6.8 8.2
83 150 4.4 4.9 5.5 6.4 6.9 8.1 9.2 10.6 12.8
18 10 0.2 0.3 0.3 0.4 0.4 0.4 0.5 0.5 0.6
28 50 1.2 1.3 1.4 1.6 1.8 2.0 2.3 2.6 3.1
56 100 2.4 2.7 3.0 3.4 3.7 4.3 4.8 5.5 6.6
83 150 3.8 4.2 4.7 5.4 5.8 6.7 7.6 8.6 10.3
18 10 0.2 0.2 0.3 0.3 0.3 0.4 0.4 0.5 0.5
28 50 1.0 1.2 1.3 1.4 1.6 1.8 2.0 2.3 2.7
56 100 2.2 2.4 2.7 3.0 3.3 3.7 4.2 4.7 5.6
83 150 3.4 3.8 4.2 4.8 5.1 5.8 6.6 7.4 8.8
18 10 0.2 0.2 0.3 0.3 0.3 0.3 0.4 0.4 0.5
28 50 1.0 1.1 1.2 1.3 1.4 1.6 1.8 2.0 2.4
56 100 2.0 2.2 2.5 2.8 3.0 3.4 3.7 4.2 5.0
83 150 3.2 3.5 3.9 4.3 4.6 5.3 5.9 6.6 7.8

( ΔT ) Pipe Diameter in Inches ( IPS )

°C °F 6 8 10 12 14 16 18 20 24

18 10 1.5 1.9 2.4 2.7 3.0 3.4 3.8 4.2 5.0
28 50 7.5 9.5 11.5 13.5 14.7 16.7 18.6 20.5 24.4
56 100 15.7 19.8 24.2 28.2 30.8 34.9 38.9 43.0 51.1
83 150 24.6 31.0 37.8 44.2 48.3 54.6 61.0 67.3 80.0
18 10 1.1 1.4 1.6 1.9 2.1 2.4 2.6 2.9 3.4
28 50 5.3 6.7 8.1 9.4 10.2 11.5 12.8 14.2 16.8
56 100 11.2 14.0 16.9 19.7 21.4 24.2 26.9 29.6 35.1
83 150 17.6 21.9 26.5 30.8 33.6 37.9 42.2 46.5 55.0
18 10 0.9 1.1 1.3 1.5 1.6 1.8 2.0 2.2 2.6
28 50 4.2 5.2 6.3 7.3 7.9 9.0 9.9 10.9 12.9
56 100 8.9 11.0 13.2 15.3 16.6 18.7 20.8 22.8 27.0
83 150 13.9 17.2 20.7 24.0 26.1 29.3 32.6 35.8 42.3
18 10 0.7 0.9 1.1 1.2 1.3 1.5 1.7 1.8 2.1
28 50 3.6 4.4 5.2 6.0 6.6 7.3 8.1 8.9 10.5
56 100 7.5 9.2 11.0 12.7 13.7 15.4 17.1 18.7 22.1
83 150 11.7 14.4 17.2 19.9 21.5 24.1 26.8 29.4 34.6
18 10 0.6 0.8 0.9 1.1 1.1 1.3 1.4 1.6 1.8
28 50 3.1 3.8 4.5 5.2 5.6 6.3 7.0 7.6 8.9
56 100 6.5 8.0 9.5 10.9 11.8 13.2 14.6 16.0 18.8
83 150 10.3 12.5 14.9 17.1 18.5 20.7 22.9 25.0 29.4

TEMPERATURE DIFFERENTIAL

Determine the temperature differential to be maintained by subtracting

the ambient temperature from the uid temperature to be maintained.

(Tf – Ta )

HEAT LOSS

Use Table 1 to look up the heat loss for the proper pipe diameter and

thickness of insulation. If a rigid insulation such as calcium silicate is used,
the insulation should be oversized to the next available size. All insulations
should be sized to provide adequate space for the heating cable and allow
the joints to properly seal. The heat loss values in Table 1 include a 10%
safety factor.

STEP 1: CALCULATING HEAT LOSS REQUIREMENTS

ADJUSTMENTS TO HEAT LOSS VALUES

The heat loss values in Table 1 are based on glass ber insulation. If
other insulations are used, multiply the heat loss value by the correction

factor shown in Table 2 for your specic insulation. Heat losses are based

on outdoor applications with 20 mph wind. If piping is located indoors,
multiply the heat loss value by 0.9.

TABLE 2: INSULATION FACTORS

Preformed Pipe Insulation Correction Factor

Glass Fiber 1.00 0.250

Cellular Glass 1.84 0.400

Rigid Urethane 0.76 0.165

Mineral Fiber 1.20 0.300

Mineral Wool 1.04 0.260

Flexible Elastomer 1.16 0.290

EXAMPLE

Maintain = +4°C (+40°F)
Minimum ambient = -23 °C (-10°F)
Sprinkler piping = 3/4" diameter
Insulation = 1.0” Flexible Elastomer

Location = Unheated indoor storage facility

ADJUSTMENTS FOR HEAT SINKS

Any thermally conductive item that protrudes through the thermal
insulation will require additional heat to be applied to the pipe. The
footage shown in Table 3 and Table 4 should be added to the required
heater cable length to compensate for these extra heat loss areas. When
multiple traces are required, increase the cable adders proportionally.

Based on K factor @ 50°F ( 10°C )

mean temperature ( BTU/hr-°F-ft²/inch )

Calculate Temperature Differential Adjustments to Heat Loss (QM)

ΔT = Tf – Ta
ΔT = +4 – (-23)°C
ΔT = +27°C

Heat Loss (Q)

Use Table 1 to nd heat loss. Where desired temperature falls
between two values, use interpolation. From Table 1:

@ +27°C ΔT

Q = 6.2 Watts/m

ΔT = Tf – Ta
ΔT = +40 – (-10)°F
ΔT = +50°F

@ +50°F ΔT

Q = 1.9 Watts/ft

Adjust the heat loss for exible elastomer. From Table 2, the correction

factor is 1.16.

QM = Q x 1.16
QM = 6.2 Watts/m x 1.16
QM = 7.2 Watts/m

Since the piping is indoors, an adjustment is necessary for the absence of
wind. If piping is located indoors, multiply the heat loss value by 0.9.

QM = 7.2 Watts/m x 0.9

QM = 6.5 Watts/m

QM = Q x 1.16
QM = 1.9 Watts/ft x 1.16
QM = 2.2 Watts/ft

QM = 2.2 Watts/ft x 0.9
QM = 2.0 Watts/ft

STEP 2: SELECT THE PROPER HEATING CABLE

30

0

Nelson Type CLT self-regulating heater cable is a parallel circuit electric
heater strip. An irradiation cross-linked conductive polymer core material is
extruded over the multi-stranded, tin-plated, 18-gauge copper bus wires.

The conductive core material increases or decreases its heat output in
response to temperature changes. A thermoplastic elastomer dielectric
jacket is then extruded over the conductive core. A copper braid is

installed over this jacket providing a continuous ground path. A UV

stabilized thermoplastic elastomer overjacket is provided to cover the
braid for wet applications and exposure to the sun.

Nelson Type LT self-regulating heater cable is a parallel circuit electric
heater strip. An irradiation cross-linked conductive polymer core material is
extruded over the multi-stranded, tin plated, 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 heaters. An optional overjacket (uoropolymer or modied polyolen)
can be specied when the heater cable is to be installed in wet or corrosive

environments.

FIGURE 1: POWER OUTPUT ON METAL PIPE

CLT SELF-REGULATING HEATER CABLE

33 (10)

30 (9)

26 (8)

23 (7)

20 (6)

16 (5)

13 (4)

10 (3)

7 (2)

3 (1)

WATTS PER METER (WATTS PER FOOT)

0

C

B

A

-1

(30)5 (40)

10

15

40 50 60 70 80 90 100110 120130 140150

(50)

(5)

(10) (15)

(60)

21

(70)

(21)

27

(80)

(27)

32

(90)

(32) (38)

Temperature °C (°F)

When selecting the proper heater cable, you should verify the following
conditions:

• Maintain Temperature

• Supply Voltage

• Piping Material

CABLE SELECTION

When selecting the heating cable with the desired power output, match a
cable from Figure 1 greater than or equal to the heat loss value in Step 1.
For designs requiring more than a single run of cable, use multiple runs of
the same wattage cable to meet the heat loss requirements.

VOLTAGE ADJUSTMENT

Use of products at other than nominal voltages requires minor
adjustments in power and maximum circuit lengths. Use Power

Adjustment Multiplier from Table 4 to verify that cable selected still meets
the desired power output conditions.

PIPING MATERIAL

The actual power output of the cable is affected by the installed piping
material. If the piping system is non-metallic, additional adjustments must

be made based on the specic piping material. Please consult a product

representative for technical assistance.

A CLT3-JT
CLT23-JT

B CLT5-JT
CLT25-JT

C CLT8-JT
CLT28-JT

65

60

54

49

43

38

(100)

(110)

(43)

(120)

(49)

(130)

(54)

(140)

(60)

(150)

(65)

LT SELF-REGULATING HEATER CABLE

39 (12)

36 (11)

33 (10)

30 (9)

26 (8)

23 (7)

20 (6)

16 (5)

13 (4)

WATTS PER METER (WATTS PER FOOT)

10 (3)

7 (2)

3 (1)

0

D

A LT3

(150)

LT23

B LT 5
LT25

C LT8
LT28

D LT10
LT210

65

C

B

A

-1

(30)

10

(50)

21

(70)

32

(90)

(110)

43

(130)

54

STEP 2: SELECT THE PROPER HEATING CABLE

TABLE 3: PERFORMANCE AND RATING DATA

Maximum

Catalog Number Nominal Voltage

Segment Length

m (ft)

CLT SELF-REGULATING HEATER CABLE

CLT3-JT 120 67.4 (221) 65 (150) 85 (185)

CLT23-JT 240 162.5 (533) 65 (150) 85 (185)

CLT5-JT 120 54.3 (178) 65 (150) 85 (185)

CLT25-JT 240 139.6 (458) 65 (150) 85 (185)

CLT8-JT 120 43.3 (142) 65 (150) 85 (185)

CLT28-JT 240 105.8 (347) 65 (150) 85 (185)

Catalog Number Nominal Voltage

Maximum

Segment Length

m (ft)

Maximum Maintenance

Temperature

°C (°F)

LT SELF-REGULATING HEATER CABLE

LT3 120 99.1 (325) 65 (150) 85 (185) T6

LT23 240 198.1 (650) 65 (150) 85 (185) T6

LT5 120 82.3 (270) 65 (150) 85 (185) T6

LT25 240 164.6 (540) 65 (150) 85 (185) T6

LT8 120 64.0 (210) 65 (150) 85 (185) T5

LT28 240 128.0 (420) 65 (150) 85 (185) T5

LT10 120 54.9 (180) 65 (150) 85 (185) T5

LT210 240 109.7 (360) 65 (150) 85 (185) T5

 Electrical equipment T rating codes dene the maximum surface temperature that equipment will reach. It is used in hazardous (classied) area applications.

Maximum Maintenance

Temperature

°C (°F)

Maximum Intermittent

Exposure

°C (°F) T-Rating 

Maximum Intermittent

Exposure

°C (°F)

TABLE 4: VOLTAGE ADJUSTMENT MULTIPLIER

Catalog Number

208 Vac 220 Vac 277 Vac

Power Length

m (ft)

Power Length

m (ft)

Power Length

m (ft)

Absolute Max

Length

m (ft)

CLT SELF-REGULATING HEATER CABLE

CLT23-JT 0.71 0.32 (1.04) 0.81 0.31 (1.02) 1.34 0.30 (0.98) 162 (533)

CLT25-JT 0.80 0.31 (1.01) 0.87 0.30 (1.00) 1.22 0.31 (1.02) 140 (458)

CLT28-JT 0.87 0.30 (1.00) 0.92 0.30 (1.00) 1.12 0.31 (1.03) 106 (347)

LT SELF-REGULATING HEATER CABLE

LT23 0.76 0.28 (0.93) 0.85 0.29 (0.96) 1.27 0.33 (1.07) 198.1 (650)

LT25 0.79 0.28 (0.93) 0.87 0.29 (0.96) 1.24 0.33 (1.07) 164.6 (540)

LT28 0.84 0.28 (0.93) 0.90 0.29 (0.96) 1.19 0.33 (1.08) 128.0 (420)

LT210 0.86 0.28 (0.93) 0.92 0.29 (0.96) 1.16 0.33 (1.09) 109.7 (360)

STEP 3: DETERMINE HEATING CABLE LENGTH

The total cable requirements are based on the pipe lengths plus adders.

PIPING REQUIREMENTS

Multiply the length of each pipe by the number of cable runs required.

PIPING ADDERS

Additional heating cable will be required for heat sinks which increase the

total heat loss of the piping system. Add the footages from Table 5 to the

calculated piping requirements.

SPRINKLER ADDERS

Additional heating cable will be required for sprinklers which increase the
total heat loss of the piping system. Add the footages from Table 6 to the
calculated piping requirements and piping adders.

TABLE 5: HEAT LOSS ADDERS FOR VALVES, PIPE SUPPORTS AND FLANGES

Additional Heater Length in Meters (Feet) for Various Heat Sinks

Pipe Size Valve s

1/2 0.3 (1.0) 0.3 (1.0) 0.3 (1.0) 3x shoe length 0.1 (0.3)

3/4 0.3 (1.0) 0.5 (1.5) 0.5 (1.5) 3x shoe length 0.1 (0.3)

1 0.3 (1.0) 0.5 (1.5) 0.5 (1.5) 3x shoe length 0.1 (0.3)

1-1/2 0.5 (1.5) 0.5 (1.5) 0.5 (1.5) 3x shoe length 0.1 (0.3)

2 0.6 (2.0) 0.6 (2.0) 0.6 (2.0) 3x shoe length 0.1 (0.3)

3 0.8 (2.5) 0.6 (2.0) 0.6 (2.0) 3x shoe length 0.2 (0.5)

4 0.9 (3.0) 0.8 (2.5) 0.8 (2.5) 3x shoe length 0.2 (0.5)

6 1.1 (3.5) 0.8 (2.5) 0.8 (2.5) 3x shoe length 0.2 (0.75)

8 1.2 (4.0) 0.8 (2.5) 0.8 (2.5) 3x shoe length 0.2 (0.75)

10 1.5 (5.0) 0.9 (3.0) 0.9 (3.0) 3x shoe length 0.2 (0.75)

12 1.8 (6.0) 0.9 (3.0) 0.9 (3.0) 3x shoe length 0.2 (0.75)

14 2.1 (7.0) 0.9 (3.0) 0.9 (3.0) 3x shoe length 0.3 (1.0)

16 2.4 (8.0) 1.1 (3.5) 1.1 (3.5) 3x shoe length 0.3 (1.0)

18 2.7 (9.0) 1.1 (3.5) 1.1 (3.5) 3x shoe length 0.3 (1.0)

20 3.0 (10.0) 1.1 (3.5) 1.1 (3.5) 3x shoe length 0.3 (1.0)

24 3.7 (12.0) 1.2 (4.0) 1.2 (4.0) 3x shoe length 0.3 (1.0)

Adders are for various inline pipe ttings to compensate for greater areas of heat loss.
Note: For design conditions requiring more than a single run of heater cable, the values shown are required for each cable run.

Pipe Hanger

(Non-Isolated) U-Bolt Support Pipe Shoe Standard Flange

CABLE LENGTH

Total cable length is determined from the sum of the previous calculations.
Total Length = Piping Requirements + Piping Adders + Sprinkler Adders

Refer to gures in the Installation and Maintenance Information section for
specic installation details for sprinkler heads with sprigs, sprinkler heads

without sprigs, and dry pendant sprinklers in freezer installations. This
information is to be used together with the Installation and Maintenance

Manual for Self-Regulating Heater Cable, document number GA-1765 and

Installation Instructions for Branch Sprinkler Systems, document number

GA-1935.

TABLE 6: HEAT LOSS ADDERS FOR SPRINKLERS

Sprinkler without sprig Sprinkler with sprig Dry sprinkler for freezer installations

(Refer to Figure 3) (Refer to Figure 4) (Refer to Figure 5)

4x pipe diameter 2x sprig length 2x drop length

Additional Heater Length in Feet for Sprinklers

STEP 4: DETERMINE ELECTRICAL LOAD REQUIREMENTS

To determine the electrical requirements for your project, you must
determine the number of circuits and calculate the transformer loading.

To calculate your electrical requirements, you will need the following:

• Total cable length

• Supply voltage

• Minimum ambient/start-up temperature

NUMBER OF CIRCUITS

Use Table 4 and Table 7, if necessary, to determine your maximum circuit

length allowed. Divide your total cable length by the maximum length
to determine the number of electrical circuits required. To reduce
distribution costs, select the smallest branch circuit breaker rating as
possible.

CALCULATE TRANSFORMER LOADING

Using your selected supply voltage, use Table 8 to calculate your Amp/

VOLTAGE ADJUSTMENT

Use of products at other than nominal voltages requires minor
adjustments in power and maximum circuit lengths. Use Length

Adjustment Multiplier from Table 4 or Table 6 to verify adjusted maximum
circuit lengths.

Ft value at your selected minimum ambient/start-up temperature. To
calculate your transformer load, use the following formula:

Amps/Ft x total cable length x supply voltage / 1000 =
Transformer Load (kVA or kW)

TABLE 7: CIRCUIT BREAKER SELECTION

Max. Length in Meters (Feet) Vs. Circuit Breaker Size

Watts/M

(Watts/Ft)

Start-up

°C (°F)

15A 20A 30A 15A 20A 30A

120 Volt 240 Volt

CLT SELF-REGULATING HEATER CABLE

10 (50) 67.4 (221) 67.4 (221) 67.4 (221) 162.5 (533) 162.5 (533) 162.5 (533)

32.3 (3)

-18 (0) 63.4 (208) 67.4 (221) 67.4 (221) 126.8 (416) 162.5 (533) 162.5 (533)

-29 (-20) 57.0 (187) 67.4 (221) 67.4 (221) 114.0 (374) 152.1 (499) 162.5 (533)

10 (50) 54.3 (178) 54.3 (178) 54.3 (178) 125.9 (413) 139.6 (458) 139.6 (458)

53.8 (5)

-18 (0) 45.7 (150) 54.3 (178) 54.3 (178) 91.1 (299) 121.6 (399) 139.6 (458)

-29 (-20) 41.1 (135) 54.3 (178) 54.3 (178) 82 (269) 109.4 (359) 139.6 (458)

10 (50) 43.3 (142) 43.3 (142) 43.3 (142) 88.1 (289) 105.8 (347) 105.8 (347)

86.1 (8)

-18 (0) 32.0 (105) 42.7 (140) 43.3 (142) 64.0 (210) 85.3 (280) 105.8 (347)

-29 (-20) 29.0 (95) 38.7 (127) 43.3 (142) 57.9 (190) 77.1 (253) 105.8 (347)

Max. Length in Meters (Feet) Vs. Circuit Breaker Size

Watts/M

(Watts/Ft)

Start-up

°C (°F)

15A 20A 30A 40A 15A 20A 30A 40A

120 Volt 240 Volt

LT SELF-REGULATING HEATER CABLE

10 (50) 99.1 (325) 198.1 (650)

32.3 (3)

-18 (0) 70.1 (230) 93.0 (305) 99.1 (325) 140.2 (460) 189.0 (620) 198.1 (650)

-29 (-20) 62.5 (205) 83.8 (275) 99.1 (325) 125.0 (410) 167.6 (550) 198.1 (650)

10 (50) 68.6 (225) 82.3 (270) 140.2 (460) 164.6 (540)

53.8 (5)

-18 (0) 47.2 (155) 62.5 (205) 82.3 (270) 94.5 (310) 126.5 (415) 164.6 (540)

-29 (-20) 41.1 (135) 54.9 (180) 82.3 (270) 83.8 (275) 112.8 (370) 164.6 (540)

10 (50) 44.2 (145) 59.4 (195) 64.0 (210) 89.9 (295) 118.9 (390) 128.0 (420)

86.1 (8)

-18 (0) 30.5 (100) 39.6 (130) 59.4 (195) 64.0 (210) 61.0 (200) 80.8 (265) 120.4 (395) 128.0 (420)

-29 (-20) 27.4 (90) 35.1 (115) 53.3 (175) 64.0 (210) 53.3 (175) 71.6 (235) 106.7 (350) 128.0 (420)

10 (50) 35.1 (115) 45.7 (150) 54.9 (180) 70.1 (230) 93.0 (305) 109.7 (360)

107.6 (10)

-18 (0) 25.9 (85) 33.5 (110) 47.2 (155) 54.9 (180) 50.3 (165) 67.1 (220) 99.1 (325) 109.7 (360)

-29 (-20) 22.9 (75) 30.5 (100) 44.2 (145) 54.9 (180) 45.7 (150) 59.4 (195) 88.4 (290) 109.7 (360)

1. Circuit breakers are sized per national electrical codes.

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 gure 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.

STEP 4: DETERMINE ELECTRICAL LOAD REQUIREMENTS

TABLE 8: TRANSFORMER SIZING (AMPS/FT)

Start-up

Temperature

CLT SELF-REGULATING HEATER CABLE

10 (50) 0.037 0.055 0.080 0.013 0.019 0.025 0.023 0.028 0.034 0.035 0.040 0.045

-18 (0) 0.055 0.078 0.111 0.020 0.028 0.038 0.031 0.039 0.047 0.048 0.056 0.062

-29 (-20) 0.061 0.086 0.123 0.022 0.031 0.042 0.034 0.043 0.052 0.054 0.062 0.069

CLT3 CLT5 CLT8 CLT23 CLT25 CLT28

120 120 120 208 240 277 208 240 277 208 240 277

Start-up

Temperature

LT SELF-REGULATING HEATER CABLE

10 (50) 0.035 0.054 0.082 0.104 0.013 0.018 0.022 0.021 0.027 0.033 0.034 0.041 0.049 0.045 0.052 0.060

-18 (0) 0.052 0.078 0.120 0.140 0.020 0.026 0.033 0.031 0.039 0.048 0.050 0.060 0.071 0.060 0.070 0.081

-29 (-20) 0.058 0.089 0.134 0.160 0.022 0.029 0.037 0.035 0.045 0.055 0.056 0.067 0.080 0.069 0.080 0.093

Multiply transformer sizing by 3.28 for Amps/m.
Note: For start-up temperatures other than those shown above, interpolation may be used for sizing accuracy.

LT3 LT5 LT8 LT10 LT23 LT25 LT28 LT210

120V 120V 120V 120V 208V 240V 277V 208V 240V 277V 208V 240V 277V 208V 240V 277V

STEP 5: CONNECTION KITS AND ACCESSORIES

Nelson’s PLT Series non-metallic connection kits are UL (Underwriter's

Laboratory) and CSA (Canadian Standards Association) approved for use
in freeze protection application for wet sprinkler piping systems when
used with approved Nelson heating cables. PLT Series connection kits are

approved for use with all Nelson CLT and LT Series eld-fabricated heating

cables.

FIGURE 3: TYPICAL FREEZE PROTECTION SYSTEM FOR SPRINKLER LINES

LT-ST Tee Splice

Connecon Kit

PLT-BC Power

Connecon Kit

CM-2201 Electronic

Controller

Enclosures supplied in PLT Series connection kits are rated NEMA 4X. In
addition to power connection kits and end seals, Nelson also provides
splice connections, tee splice connections and associated accessories as
required to complete your entire heat tracing installation.

Thermal

Insulaon

LT-ME End Seal or PLT-L

Heang Cable

Oponal Lighted End Seal

Sprinkler Head
on Sprig Piping

TABLE 9: CONNECTION KITS AND GENERAL ACCESSORIES

Catalog Number Units Each Description

PLT-BC-J-3 1 Power Connection Kit for 1/2" to 3” diameter pipe

PLT-BC-J-12 1 Power Connection Kit for 3 1/2" to 12” diameter pipe

PLT-BC-J-20 1 Power Connection Kit for 12 1/2" to 20” diameter pipe

PLT-BS-U-3 1 Splice Connection Kit for 1/2" to 3” diameter pipe

PLT-BS-U-12 1 Splice Connection Kit for 3 1/2" to 12” diameter pipe

PLT-BS-U-20 1 Splice Connection Kit for 12 1/2" to 20” diameter pipe

PLT-L(X)-J-3 1 Lighted End Seal for 1/2" to 3” diameter pipe, replace (X) with voltage

PLT-L(X)-J-12 1 Lighted End Seal for 3 1/2" to 12” diameter pipe, replace (X) with voltage

PLT-L(X)-J-20 1 Lighted End Seal for 12 1/2" to 20” diameter pipe, replace (X) with voltage

LT-SS 5 Splice Connection Kit, heat shrink version

LT-ST 5 Tee Splice Connection Kit, heat shrink version

GT-6 1 Fiberglass Tape, 18 meters (60 feet)

GT-60 1 Fiberglass Tape, 55 meters (180 feet)

AT-50 1 Aluminum Foil Tape, 46 meters (150 feet)

WS-100 1 Warning Signs

LT-ME 5 End Seals, molded silicone

LT-MP 5 Power End Terminations, molded silicone

LT-SE 5 End Seals, heat shrink version

LT-SP 5 Power End Terminations, heat shrink version

Note: PLT Series Connection Kits include both the end seal and/or power end terminations for a single heat tracing segment. Additional components may be

required based on the specic piping system conguration.

Addional heang cable, see TABLE 6
for specific requirements

Thermal Insulaon, install per NFPA 13

recommendaons for spray shadowing

INSTALLATION AND MAINTENANCE INFORMATION

For proper installation of Nelson CLT and LT Series heating cables on sprinkler piping, refer to the details below. These details are

supplemental to the Installation and Maintenance Manual for Self-Regulating Heater Cable, document number GA-1765 and Installation
Instructions for Branch Sprinkler Systems, document number GA-1935.

FIGURE 3: SPRINKLER HEAD WITHOUT SPRIG

Thermal Insulaon, install per NFPA 13

recommendaons for spray shadowing

Addional heang cable, see TABLE 6
for specific requirements

FIGURE 4: SPRINKLER HEAD WITH SPRIG

Thermal Insulaon, install per NFPA 13

recommendaons for spray shadowing

Addional heang cable, see TABLE 6
for specific requirements

FIGURE 5: DRY PENDANT SPRINKLER IN FREEZERS

Freezer wall thermal insulaon

1. The illustrations in Figures 3 – 6 are basic examples of various sprinkler installations and are for reference only. For sprinkler and/or sprinkler piping not
reected in these details, please consult your local representative for optional recommendations.

2. Use on insulated appropriately Listed or Certied steel schedules 5, 10, 20 and 40 standpipe, supply lines, and branch lines containing sprinklers up to and
including 6 inch size. Includes use on elbows, tees, anges, hangers and valves. Appropriately Listed or Certied berglass insulation with a k-factor of 130­140 W/m-K @ 24°C (0.25-0.27 BTU-in / hr-°F-ft

3. For systems having piping which connects between buildings, in unheated areas, coolers or freezers where the temperature is -40°C (-40°F) or greater.

4. For use in Ordinary Hazard Occupancies only as specied in NFPA 13 the Standard for the Installation of Sprinkler System. The system must comply with the
obstruction requirements of NFPA 13 so that the thermal insulation over the trace heating does not unacceptably obstruct the sprinkler or cover the
wrench boss.

5. For use with sprinkler heads with a temperature rating of 68°C (155°F) or higher.

2

@ 75°F) with weatherproof cladding must be used.

Addional heang cable, see TABLE 6
for specific requirements

Emerson brings integrated manufacturing
solutions to diverse industries worldwide.
Our comprehensive product line, extensive
experience, world-class engineering and
global presence enable us to implement
solutions that give our customers the
competitive edge. Nelson Heat Trace is our
industrial line of heating cables solution.
They provide a full line of products and
expertise for the powering, controlling and

monitoring of pipeline temperatures.

For over 150 years, our electrical product
brands have been providing a rich tradition
of long-term, practical, high quality
solutions with applications ranging from
the construction and safe operation of
petrochemical and process plants to
providing quality power that precisely
controls automotive robotic production.

Engineers, distributors, contractors,
electricians and site maintenance
professionals around the world trust
Emerson brands to make electrical
installations safer, more productive and

more reliable.

The Appleton Group business unit of Emerson

is organized into three focused groups that
provide distributors and end users expert
knowledge and excellent service.

Electrical Construction Materials

This group is made up of the Appleton and

O-Z/Gedney brands. They manufacture
a broad range of electrical products
including conduit and cable ttings, plugs
and receptacles, enclosures and controls,
conduit bodies and industrial and hazardous
lighting. Whether the application is hazardous
location, industrial or commercial, the
electrical construction materials group has
the products to meet your needs.

Power Quality Solutions

The SolaHD brand offers the broadest

power quality line, including uninterruptible
power supplies, power conditioners, voltage

regulators, shielded transformers, surge

protection devices and power supplies.

Heating Cable Systems

This group is made up of the EasyHeat

and Nelson brands. They offer a broad
range of electrical heating cable products
for residential, commercial and industrial
applications.

Asia/Pacic
+ 65.6556.1100

Australia

+ 61.3.9721.0348

Canada

+ 1.888.765.2226

China

+ 86.21.3338.7000

Europe

+ 33.3.22.54.13.90

Mexico/Latin America
+ 52.55.5809.5049

Middle East/Africa/India
+ 971.4.881.8100

United States

+ 1.800.621.1506

Appleton Group

9377 W. Higgins Road
Rosemont, IL 60018

1.800.331.7325
nelsonheaters.com

Appleton Grp LLC d/b/a Appleton Group. The Appleton and Emerson logos are registered in the U.S. Patent and Trademark Ofce.
EasyHeat, Inc. is a wholly owned subsidiary of Appleton Grp LLC. All other product or service names are the proper ty of their registered owners. © 2016, Appleton Grp LLC.
All rights reserved. GA-2499 Rev.0