Electric Heat Tracing

INSTALLATION PROCEDURES
Electric Heat Tracing
Complete Electric Heat Tracing System . . .

Types of Heating Cables1 . . .

Self-Regulating Heating Cables:
BSX™ (refer to Form TEP0067U)
1725 II 2 G & D Ex e II T5 or T6 DEMKO 02ATEX0132424, UL 06.0013 Ex e II T5 or T6

RSX™ 15 (refer to Form TEP0048U)2

1725 II 2 G Ex e II T4 to T6 KEMA 07ATEX0179, KEMA 07.0052 Ex e II T4 to T6

HTSX™ (refer to Form TEP0074U)

1725 II 2 G Ex eb IIC T2 or T3, II 2 D Ex tb IIIC T300°C or T200°C FM 12ATEX0014
FMG 12.0003 Ex eb IIC T2 or T3, Ex tb IIIC T300°C or T200°C

KSX™ (refer to Form TEP0072U)

1725 II 2 G Ex e II T3 to T6, II 2 D Ex tD A21 IP66/IP67 T200°C to T85°C FM 07ATEX0027
FMG 06.0009 Ex e II T3 to T6,
Ex tD A21 IP66/IP67 T200°C to T85°C

VSX™ (refer to Form TEP0008U)

1725 II 2 G & D Ex e II T3 DEMKO 02ATEX0152667
UL 05.0008x Ex e II T3

Power-Limiting Heating Cable:

HPT™ (refer to Form TEP0011U)
1725 II 2 G Ex e II T2 to T6, II 2 D Ex tD A21 T300°C to T85°C FM 07ATEX0028
FMG 06.0006 Ex e II T2 to T6

Parallel Constant Watt Heating Cable:

FP (refer to Form TEP0016U)3
1725 II 2 G Ex e II T3 to T6, II 2 D Ex tD A21 IP66/IP67 T200°C to T85°C FM 07ATEX0016
FMG 06.0008 Ex e II T3 to T6,
Ex tD A21 IP66/IP67 T200°C to T85°C

Series Constant Watt Heating Cables:

HTEK™ (refer to Form TEP0022U)
1725 II 2 G Ex eb IIC T260°C (T2) to T6, II 2 D Ex tb IIIC T260°C to T85°C FM 11ATEX0050
CCVE 11.0002 Ex eb IIC T260°C (T2) to T6, Ex tb IIIC T260°C to T85°C

TEK™ (refer to Form TEP0021U)

1725 II 2 G Ex eb IIC T260°C (T2) to T6, II 2 D Ex tb IIIC T260°C to T85°C FM 11ATEX0050
CCVE 11.0002 Ex eb IIC T260°C (T2) to T6, Ex tb IIIC T260°C to T85°C

TESH™ (refer to Form TEP0070U)

1725 II 2 G Ex e IIC T2 To T6 Gb, II 2 D Ex tb IIIC IP6X T260°C to T80°C Db ISSeP 10ATEX015X

Notes . . .
1. Refer to the heating cable product specification sheets for temperature ratings as limited by the manufacturer.
2. For foundation heating with RSX, refer to Form TEP0059.
3. For foundation heating with FP, refer to Form TEP0079.

1
Electric Heat Tracing
The following installation procedures are for the installation Complete Electric Heat Tracing System . . .
of a Thermon electric heat tracing system1. The installation
A complete electric heat tracing system may typically include
must comply with Thermon requirements and be installed
the following components2:
in accordance wit the regulations as per standard EN-IEC
60079-14 and EN-IEC 60079-30-2 for hazardous areas 1. Electric heat tracing cable1, 5 (self-regulating, power-
(where applicable), and any other applicable national and limiting, parallel constant watt or series constant watt).
local electric codes. 2. Power connection kit.
3. RTD sensor or control thermostat3.
Individuals installing these products are responsible for 4. In-line/T-splice kit (permits two or three cables to be
complying with all applicable safety and health guidelines. spliced together).
Proper personal protective equipment, or PPE, should be 5. Cable end termination.
utilized during installation. Contact Thermon if you have
5a. End of circuit light kit.
any additional questions.
6. Attachment tape (use on 30cm intervals or as required by
Applications . . . code or specification).
1. Electric heat tracing cables are used for freeze protection 7. “Electric Heat Tracing” label (peel-and-stick label attaches
or temperature maintenance of piping, tanks and to insulation vapor barrier on 3m intervals or as required
by code or specification).
instrumentation. This set of instructions covers typical
piping applications. For installation details on tanks and 8. Thermal insulation4 and vapor barrier (by others).
instrumentation, refer to the Installation Guides on our The absence of any of these items can cause a system to
website www.thermon.com. malfunction or represent a safety hazard.
2. Heat tracing cables may be installed in ordinary Notes . . .
1. Refer to Page 1 for cable types and approval.
(nonclassified) and hazardous (classified) locations
2. Illustration depicts a typical self-regulating heating circuit.
depending on the specific cable options and approvals1. 3. Temperature control is recommended for all freeze protection and temperature
maintenance heat tracing applications.

Site Practice . . . 4. All heat-traced lines must be thermally insulated.

5. Refer to Thermon form number PN50273U for installation instructions for MI
1. Provide protective clothing, and other protective heating cable.
equipment needed to isolate employees from potential
Illustration A: Typical Heat Tracing Installation
arc flash and shock hazards identified in the analysis.
2. Provide training to employees for understanding the 5a
4
purpose/function of the electrical heat tracing and the
electrical power supply/control equipment. In addition,
how to recognize and avoid the hazards associated with 5
operation and maintenance.
3. Apply safe work practices including the following:
• Identify the circuit or equipment to be de-energized and
all possible sources of electrical energy supplies to the
specfic circuit or equipment. 8

• Disconnect both legs of the power supply cable at the 6

circuit breakers, disconnect switches, and any other
applicable points. 7

• Apply lockout/tagout devices according to established

procedures.
• Visually verify that the circuit disconnect devices are
open prior to connecting power cable to heat tracers.
1
• Test for absence of voltage with an approved voltmeter 3
(where the voltmeter is tested on a known circuit voltage
prior to and immediately following application).
• For protection against accidental energizing of supply
conductors, apply temporary jumpers rated for the
available fault duty between each supply conductor and 2
earth/ground.

2
Electric Heat Tracing
Upon Receiving Cable . . . Before Installing Cable . . .
1. Upon receiving heating cable, check to make sure the 1. Be sure all piping and equipment to be traced is
proper type and output have been received. All flexible completely installed and pressure tested.
cables have the catalog number, voltage rating and watt 2. Surface areas where heat tracing is to be installed must be
output printed on the jacket. reasonably clean. Remove dirt, rust and scale with a wire
2. Visually inspect brush and oil and grease films with a suitable solvent.
cable for any
damage incurred
Initial Installation . . .
during shipment. 1. Locate the cable on the lower quadrant of the pipe at the
The heating cable should be 4 or 8 o’clock position. If accessibility is a problem the
tested to ensure electrical integrity cable may be installed at the 10 or 2 o’clock position.
with at least a 500 Vdc megger Temperature sensor should be located at least 90° from
between the heating cable bus wires and the heating all heating cables. Refer to Illustration B for Heating Cable
cable metallic braid. IEEE 515 and EN-IEC 60079-30 vs. Sensor Location.
recommend that the test voltage for polymer insulated
heating cables be 2500 Vdc. Minimum resistance should 2. Begin temporary installation at the proposed end-of-
be 20 megohms. Connect the positive lead of the megger circuit location and lay out heating circuit on the pipe,
to the cable bus wires and the negative lead to the allowing extra cable for the power connection and for
metallic braid. any splice locations1. Refer to Illustration C for temporary
(Record 1 on Insulation Resistance Test Page 9 and 10) installation.

3. Store in dry location. 3. Make heating cable allowances for valves, flanges, elbows
and supports as per the applicable drawings and table on
pages 5 and 6 of these installation procedures.

Illustration B: Heating Cable vs. Sensor Location Temperature Sensor

(Typical)

45º Pipe Wall

90º

45º
45º
90º 45º 45º 45º 45º
Heating Cable
(Typical)
Single Cable Installation Dual Cable Installation Triple Cable Installation

Proposed End-of-Circuit
Illustration C: Temporary Installation Location

Pipe Support

Notes . . .
1. Termination kits to fabricate a heat tracing circuit are not
addressed in detail in these installation procedures. Refer
Cable Allowance for
to installation instructions included with cable termination
In-Line Heat Sinks kits or contact Thermon for specific instructions to
Proposed Power fabricate heating cable.
Connection Location

3
Electric Heat Tracing
Installation on Elbows, Supports and Flanges . . .
1. Install heating cable in accordance with Illustrations D, 4. Flanges: Allow cable to be looped around pipe on each
E and F below. Secure heating cable to piping using side of and adjacent to the flange. Heating cable must
attachment tape. maintain contact with flange when bending around pipe
flanges to compensate for additional heat loss.
2. Elbows: Locate the cable on the outside radius of an
elbow to provide sufficient heat to compensate for the 5. Refer to the product specifications sheet for minimum
added piping material. Secure the cable to the pipe on bend radius for the specific cable type. Do not exceed
each side of the elbow with attachment tape. bend radius when completing installation.
3. Pipe Supports: Insulated pipe supports require no
additional heating cable. For uninsulated supports, allow
two times the length of the pipe support plus an additional
40 cm of heating cable.

Illustration D: Pipe Elbow Illustration E: Pipe Support1

Attachment Tape
(Typical)

Heating Cable Heating Cable

Attachment Tape
(Typical)

8 cm

Illustration F: Pipe Flange Support

8 cm Length

Attachment Tape
(Typical)

Heating Cable

Circuit Layout on Support

Note . . .
1. Only applicable for pipe ≥ 50mm.

30 cm
Note: Flange allowance will vary based on method of
insulating flange and adjacent piping.

4
Electric Heat Tracing
Installation on Valves and Pumps . . . Table 1: Valve and Pump Allowances1
Pipe Valve Allowance (M) Pump Allowance (M) Flange
1. Install heating cable in accordance with Illustrations G and
Size Screwed Allowance
H below. Secure heating cable to piping using attachment (mm) or Welded Flanged Butterfly Screwed Flanged (M)
tape. 12 0.20 0.30 0.00 0.30 0.61 0.38
2. Additional cable is required to provide extra heat at 20 0.20 0.46 0.00 0.46 0.91 0.46
25 0.30 0.61 0.30 0.61 1.22 0.46
valves, pumps and miscellaneous equipment to offset the
32 0.50 0.61 0.30 0.91 1.37 0.61
increased heat loss associated with these items. Refer to
40 0.50 0.76 0.46 0.91 1.52 0.61
Table 1 for estimated cable requirements for installation
50 0.60 0.76 0.61 1.22 1.68 0.69
on typical valves and pumps. Allowances shown in
80 0.80 1.07 0.76 1.52 2.13 0.69
Table 1 are for 150 pound valves. More cable is required 100 1.20 1.52 0.91 2.44 3.05 0.84
for higher rated valves. Refer to heat trace isometric 150 2.10 2.44 1.07 4.27 4.88 0.99
drawing for project specific allowances. 200 2.90 3.35 1.22 5.79 6.71 1.14
3. Install heating cable on valves and pumps utilizing a 250 3.80 4.27 1.22 7.62 8.53 1.30
300 4.60 5.03 1.52 9.14 10.06 1.52
looping technique (this allows the valve or pump to be
350 5.50 5.94 1.68 10.97 11.89 1.68
removed if required). Crossing constant watt heating
400 6.60 7.01 1.83 13.11 14.02 1.83
cable over itself should be avoided.
450 7.80 8.23 1.98 15.54 16.46 1.98
4. Refer to the product specifications sheet for minimum 500 8.70 9.14 2.13 17.37 18.29 2.21
bend radius for the specific cable type. Do not exceed 550 10.40 10.97 2.44 20.73 21.95 2.51
bend radius when completing installation. 600 12.20 12.80 3.05 24.38 25.60 3.05
Note . . .
1. The valve allowance given is the total amount of additional cable to be installed on
the valve. If multiple tracers are used, total valve allowance may be divided among
the individual tracers. The total valve allowance may be alternated among tracers for
multiple valves in a heat trace circuit. Allowances are for 150 pound valves. More
cable is required for higher rated valves. Refer to heat trace isometric drawing for
project specific allowances.

Illustration G: Typical Valve Detail Illustration H: Typical Pump Detail

Attachment Tape
(Typical)

Heating Cable

Heating Cable

Attachment Tape Heating Cable Serpentined on Pump

(Typical)

Heating Cable Serpentined on Valve

Circuit Layout on Valve Circuit Layout on Pump

5
Electric Heat Tracing
Completing the Installation . . .
1. Begin final cable attachment by securing the end-of-circuit 3. Complete splice connections (if required) in accordance with
termination kit and working back toward the power supply. the installation instructions provided with the splice kit.
Refer to Illustration I. 4. Before making power connections, The heating cable
• Flexible heating cables are to be installed using attachment should be tested to ensure electrical integrity with at
tape. Circumferential bands of tape should be installed at least a 500 Vdc megger between the heating cable
30 cm intervals to keep the cable in good contact with bus wires and the heating cable metallic braid. IEEE
the pipe. Refer to Table 2 below to calculate the number 515 and EN-IEC 60079-30 recommend that the test
of rolls of attachment tape required based on the pipe voltage for polymer insulated heating cables be 2500
diameter1. Vdc. Minimum resistance should be 20 megohms.
• Avoid crossing series constant watt heating cables. (Record 2 on Insulation Resistance Test Page 9 and 10)
• If applicable, refer to installation details provided with 5. Install power connection kit in accordance to the detailed
the project drawings or contact Thermon for additional installation instructions provided with the kit.
information regarding installation. 6. Secure temperature sensor (if required) to pipe utilizing
2. In addition to the circumferential tape requirements, a attachment tape.
continuous covering of aluminum foil tape may be required Notes . . .
when: 1. Table 2 assumes circumferential bands every 30 cm along the length of the process
piping.
• Spray or foam2 thermal insulation is applied.
2. Verify exposure temperature of heating cable versus curing temperature of
• Heat tracing nonmetallic piping. insulation.
• Design requirements dictate the use of aluminum tape.

Illustration I: Final Cable Attachment

Proposed End of Circuit

Attachment Tape

Proposed Power Supply

Table 2: Attachment Tape (Value Represents Approximate Linear Pipe Length Allowance Per Roll)

Pipe Size
12-25 32 40 50 80 100 150 200 250 300 350 400 450 500 600 750
mm
Length of Pipe/
Roll of Tape 109.7 79.2 67.0 54.9 45.7 36.6 27.4 21.3 18.2 15.2 12.2 10.7 9.1 7.6 6.0 4.6
m

6
Electric Heat Tracing
Circuit Protection Requirements . . . Final Inspection and Documentation . . .
1. Over-current protection (typically circuit breakers) is 1. After the installation of the thermal insulation and
required for each branch circuit. This protection must weather barrier but BEFORE ENERGIZING THE HEATING
isolate all power conductors from the supply. CIRCUIT, the insulation resistance test should be
2. For typical installations (with TT and TN grounding repeated. This should call attention to any damage to
systems), a means of protection against earth faults is the heating cable that may have occurred during the
required that includes a residual-current protective device insulation installation.
for each branch circuit. For fixed-level earth/ground- (Record 3 on Insulation Resistance Test Page 9 and 10.)
fault circuit interrupters, a minimum 30 mA trip level is For Series Heating Cables, measure the electric loop resistance
recommended. The preferred trip level for adjustable and record measured Ohms (Record 3 on Page 10.)
devices is 30 mA above any inherent capacitive leakage 2. It is recommended that the circuit be temporarily
characteristic of the heater as specified by the heat energized so that the volts, amps, pipe temperature and
tracing supplier. Where conditions of maintenance and ambient temperature may be recorded. Take the values
supervision ensure that only qualified persons will service after 5 minutes of energizing. This information may be of
the installed systems, and continued circuit operation value for future reference and should be maintained for
is necessary for the safe operation of the equipment the historical operating data log.
or processes, earth-fault detection without interruption (Record 4 on Insulation Resistance Test Page 9 and 10)
is acceptable if alarmed in a manner to assure an 3. Stabilized design can be used for self-regulating, power-
acknowledged response. limiting and constant watt heating cables without a limiting
3. For IT grounding systems, a means of protection device to determine the T-class through the use of the
against earth faults is required that includes an electrical Thermon CompuTrace software or Thermon Engineering.
insulation monitoring device that shall disconnect the 4. Series heating cable output and T-rating are dependent
supply whenever the electrical resistance is not greater upon supply voltage, cable resistance, temperature
than 50 ohms/volt of rated voltage. conditions as well as additional variables through the
Thermal Insulation . . . use of the Thermon CompuTrace software or Thermon
Engineering.
1. Before installing thermal insulation, insulation resistance
5. The maximum temperatures provided by Thermon’s
test should be conducted. The cable should be tested
CompuTrace software and by Thermon engineering are
with a test voltage of at least 500 Vdc. However,
calculated to the methods and requirements of
for polymer insulated heating cables, 2500 Vdc is
EN-IEC 62086-2 and EN-IEC 60079-30.
recommended. The minimum acceptable level should not
be less than 20 megohms. 6. If stabilized design is used, the end user must record the
system parameters and the area T-class, and keep these
2. The need for properly installed and well-maintained
records for the time the heating cable is in operation.
thermal insulation cannot be overemphasized. Without
insulation, heat losses are generally too high to be offset 7. Inspect system on a regular basis at least once per year.
by a conventional heat tracing system. Record all information after conducting test. If the system
fails any test, refer to Thermon’s Maintenance and Trouble
3. In addition to piping and in-line equipment such as pumps
Shooting Guide for assistance. De-energize circuits affected
and valves, all heat sinks must be properly insulated. This
and make the necessary repairs immediately.
includes pipe supports, hangers, flanges and, in most
cases, valve bonnets. 8. Verify the setting of the maximum control device, if
4. Regardless of the type or thickness of insulation used, a provided to limit the T-rating for the circuit design, to
protective barrier should be installed. This protects the ensure it limits the maximum surface temperature to be in
insulation from moisture intrusion, physical damage and compliance with clause 4.4.3 of EN-IEC 60079-30-1.
helps ensure the proper performance of the heat tracing Maintenance and Repair . . .
system. Seal around all penetrations through the thermal
insulation. 1. Refer to form TEP0066-Electric Heat Tracing Maintenance
5. Apply “Electric Heat Tracing Caution” labels to the and Trouble Shooting Guide.
insulation vapor barrier on 3m intervals or as required
by code or specification. The labels are supplied with
Thermon connection kits.

7
 Cable Testing Report
1. Refer to these Installation Procedures for general installation procedures, requirements and guidelines.
2. Upon receiving heating cable, check the cable to make sure the proper type and output have been received. All flexible
cables have the catalog number, voltage rating and watt output printed on the outer jacket.
3. Visually inspect cable for any damage incurred during shipment. The heating cable should be tested to ensure electrical
integrity with at least a 500 Vdc megger between the heating cable bus wires and the heating cable metallic braid.
IEEE 515 and EN-IEC 60079-30 recommend that the test voltage for polymer insulated heating cables be 2500 Vdc.
Minimum resistance should be 20 megohms.
(Record 1 on Insulation Resistance Test Page 9 and 10)
A. Connect the positive lead of the megger to the cable bus
wires.
B. Connect the negative lead of the megger to the metallic braid.
C. Energize the megger and record the reading. Readings
between 20 megohms and infinity are acceptable. Readings
below 20 megohms may mean the electrical insulation has
been damaged. Recheck the heating cable for physical damage between the braid and the heating element; small cuts or
scuffmarks on the outer jacket will not affect the megger reading unless there was actual penetration through the braid
and dielectric insulation jacket.
4. Once the installation is complete, but prior to installation of thermal insulation, recheck the heating cable with at least a
500 Vdc megger between the heating cable bus wires and the heating cable metallic braid. IEEE 515 and EN-IEC 60079-30
recommend that the test voltage for polymer insulated heating cables be 2500 Vdc. Minimum resistance should be 20
megohms. (Record 2 on Insulation Resistance Test Page 9 and 10)
5. After the thermal insulation is installed, the insulation resistance test should be repeated. Minimum resistance should be 5
megohms. (Record 3 on Insulation Resistance Test Page 9 and 10.) For Series Heating Cables, measure the electric loop
resistance and record measured Ohms (Record 3, Page 10.)
6. After the thermal insulation is installed and power supply is completed, record the panel and circuit breaker information.
Ensure all junction boxes, temperature controllers, cable glands, etc. are properly secured. Set the temperature controller
(if applicable) to the manual setting and apply rated voltage to the heat tracing circuit(s) for 5 minutes. Record the ambient
temperature, measure and record the circuit(s) voltage and current.
(Record 4 on Insulation Resistance Test Page 9 and 10)

NOTE: To ensure the heating cable warranty is maintained through installation, the testing outlined
on this sheet must be completed on the installed heating cables.

8
 Checklist for Self-Regulating and Power-Limiting Heat Tracing
General Information
Installation
Project Number: Contractor:
Thermon Reference
Unit Number: Number:
Customer Ref. Number: Inspector:

Record 1: Prior to Installation

Cable Type: Reel Number:

Insulation Resistance:
Reel Length (M): (M Ohms)*
Tested By/Date: Witnessed By/Date:

Record 2: After Cable Installation

Line Number: Thermostat Number:

Equipment Number: Junction Box Number:

Unused Entries
Circuit/Heater Number: Plugged Off:
Circuit Switch Number: Heater Length (M):
Metal Sheath Connected Insulation Resistance:
to Earth/Ground: (M Ohms)*
Tested By/Date: Witnessed By/Date:

Record 3: After Thermal Insulation is Installed

Insulation Resistance:
Insulation Watertight: (M Ohms)*
Tested By/Date: Witnessed By/Date:

Record 4: Final Commissioning

Panel Number: Ambient Temp. (°C):

Breaker Number: Pipe Temp. (°C):

Recorded Amps
Volts: (after 5 min.):
Tested By/Date: Witnessed By/Date:

*NOTE: Minimum acceptable insulation resistance should be 20 megohms for Records 1 and 2 and
5 Megohms for Record 3.

9
 Checklist for Installation of Series Heating Cables
General Information

Project Number: Electrical Contractor:

Unit Number: Reference Number:

Customer Ref. Number: Inspector:

Record 1: Prior to Installation

Cable Type: Insulation Resistance (M Ohms):

1 2
Single Phase L-Earth
Reel Length (M):
L1-Earth
1 2
3 Phase L2-Earth
Reel Number:
L3-Earth
Tested By/Date: Witnessed By/Date:

Record 2: After Cable Installation

Line Number: Junction Box Number:

Unused Entries
Equipment Number: Plugged Off:
1 2
Circuit/Heater Number: Heater Length (M):

Circuit Switch Number: Insulation Resistance (M Ohms):

Braid Connected Single Phase L-Earth
to Earth/Ground: L1-Earth
3 Phase L2-Earth
Thermostat Number:
L3-Earth
Tested By/Date: Witnessed By/Date:

Record 3: After Thermal Insulation is Installed Insulation Watertight:

Insulation Resistance (M Ohms): Electrical Loop Resistance (Ohms):

Single Phase L-Earth Single Phase L-L
L1-Earth L1-L2
3 Phase L2-Earth 3 Phase L2-L3
L3-Earth L3-L1
Tested By/Date: Witnessed By/Date:

Record 4: Final Commissioning

Panel Number: Ambient Temp. (°C):

Breaker Number: Pipe Temp. (°C):

Recorded Amps
Volts: (after 5 min.):
Tested By/Date: Witnessed By/Date:

*NOTE: Minimum acceptable insulation resistance should be 20 megohms for Records 1 and 2 and
5 Megohms for Record 3.
10
For additional product information on Thermon heating cables, refer to the individual product specifications.
BSX™ (refer to Form TEP0067U)
RSX™ 15 (refer to Form TEP0048U)
HTSX™ (refer to Form TEP0074U)
KSX™ (refer to Form TEP0072U)
VSX™ (refer to Form TEP0008U)
HPT™ (refer to Form TEP0011U)
FP (refer to Form TEP0016U)
HTEK™ (refer to Form TEP0022U)
TEK™ (refer to Form TEP0021U)
TESH™ (refer to Form TEP0070U)

THERMON . . . The Heat Tracing Specialists®

www.thermon.com

European Headquarters Corporate Headquarters

Boezemweg 25 • PO Box 205 100 Thermon Dr. • PO Box 609 For the Thermon office nearest you
2640 AE Pijnacker • The Netherlands San Marcos, TX 78667-0609 • USA visit us at . . .
Phone: +31 (0) 15-36 15 370 Phone: +1 512-396-5801 www.thermon.com
Specifications and information subject to change without notice. PN50207U-0412