Thermon FLX Self-Regulating Installation Procedures Manual

TM

FLX

Self-Regulating

Winterization/Freeze Protection

INSTALLATION PROCEDURES

FLX

FLX

TM

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Self-Regulating

Self-Regulating

Refer to the “FLX Cable Testing Report” for required recording
of test data and circuit information.

Upon Receiving Cable . . .

1. Upon receiving heating cable, check to make sure the proper
type and output have been received. All cables are printed
on the outer jacket with part number, voltage rating and watt
output.

2. 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 megohmmeter (meg­ger) between the heating cable bus wires and the heating
cable metallic braid. IEEE 515.1 recommends that the test
voltage for polymer insulated heating cables be 2500 Vdc.
Minimum resistance should be 20 megohms. (Record 1 on
Cable Testing Report.)

Typical Heat Tracing Installation . . .

A complete electric heat tracing system will typically in­clude the following components:

1. Electric heat tracing
cable.

2. Power connection kit.

3. Control thermostat (may
be remote ambient
sensing control.)

4. In-line/T-splice
kit (permits two
or three cables to
be spliced together).

5. Cable end termination.

6. Attachment tape (use on 12”
intervals or as required by code
or specication).

7. “Electric Heat Tracing” label (peel-and-stick
label attaches to insulation vapor barrier
on 10’ intervals or as required by code or
specication).

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8

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1

Connect the positive lead of the megger to the cable bus
wires and the negative lead to the metallic braid.

CAUTION: DO NOT connect power to heating
cable while it is on reel or in shipping carton.

Before Installing Cable . . .

1. Be sure all piping and equipment to be traced is completely
installed and pressure tested.

2. Surface areas where heat tracing is to be installed must be
reasonably clean. Remove dirt, rust and scale with a wire
brush and oil and grease lms with a suitable solvent.

8. Thermal insulation and vapor barrier
(by others).

The absence of any of these items
can cause a system to malfunction
or represent a safety hazard.

The National Electric Code and Canadian Electrical
Code require ground-fault protection be provided
for all electric heat tracing.

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2

2

Initial Installation . . .

INSTALLATION PROCEDURES

1. Begin temporary installation at the proposed end-of-circuit
location and lay out heating circuit on the pipe, allowing ex­tra cable for the power connection and for any splice loca­tions. Refer to illustration below for temporary installation.

Temporary Installation

Proposed Power

Connection Location

Cable Allowance for

In-Line Heat Sinks

Installation on Fittings and Equipment . . .

2. Make heating cable allowances for valves, anges, elbows
and supports as per the applicable drawings and table on
pages 2 and 3 of these installation procedures. See product
specications sheet for heating cable minimum bend radius.

Proposed End-of-Circuit

Location

Pipe Support

1. Install heating cable in accordance with illustrations below.
Secure heating cable to piping using attachment tape.

2. Elbows: Locate the cable on the outside radius of an elbow
to provide sucient heat to compensate for the added pip-

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 15” (40 cm) of
heating cable.

ing material. Secure the cable to the pipe on each side of
the elbow with attachment tape.

Pipe Elbow Pipe Support

Heating Cable

Attachment Tape

(Typical)

Heating Cable

3” Min.

(8 cm)

Attachment Tape

(Typical)

3” Min.

(8 cm)

Support

Length

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Self-Regulating

4. Flanges: Allow cable to be looped around pipe on each side
of and adjacent to the ange. Heating cable must maintain
contact with ange when bending around pipe anges to
compensate for additional heat loss.

Typical Flange Detail

Heating Cable

12” Max.

Note:
Flange allowance will vary based on method of insulating ange and adjacent piping.

(30 cm)

Attachment Tape

(Typical)

5. Additional cable is required to provide extra heat at valves,
pumps and miscellaneous equipment to oset the in­creased heat loss associated with these items. Refer to
Table 1 for estimated cable requirements for installation on
typical valves and pumps.

6. Install heating cable on valves and pumps utilizing a looping
technique (this allows the valve or pump to be removed if
required).

Typical Valve Details

Heating Cable

Temporary Loop of Cable on Valve

Attachment Tape

(Typical)

Table 1: Valve and Pump Allowances

Pipe
Size

½" 6" 1' 0 1' 2'

¾" 9" 1'-6" 0 1'-6" 3'

1" 1' 2' 1' 2' 4'

1¼" 1'-6" 2' 1' 3' 4'-6"

1½" 1'-6" 2'-6" 1'-6" 3' 5'

2" 2' 2'-6" 2' 4' 5'-6"

3" 2'-6" 3'-6" 2'-6" 5' 7'

4" 4' 5' 3' 8' 10'

6" 7' 8' 3'-6" 14' 16'

8" 9'-6" 11' 4' 19' 22'

10" 12'-6" 14' 4' 25' 28'

12" 15' 16'-6" 5' 30' 33'

14" 18' 19'-6" 5'-6" 36' 39'

16" 21'-6" 23' 6' 43' 46'

18" 25'-6" 27' 6'-6" 51' 54'

20" 28'-6" 30' 7' 57' 60'

24" 34' 36' 8' 68' 72'

30" 40' 42' 10' 80' 84'

Screwed Flanged Welded

Valve Type

Pump Type

Screwed Flanged

Heating Cable Attachment Tape

Heating Cable Serpentined on Valve

(Typical)

Typical Pump Detail

Heating Cable

Heating Cable Serpentined on Pump

Attachment Tape

(Typical)

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INSTALLATION PROCEDURES

Completing the Installation . . .

1. Begin nal cable attachment by securing the end-of-circuit
termination kit and working back toward the power supply.

• Flexible heating cables are to be installed using attachment

tape. Circumferential bands of tape should be installed at
12” (30 cm) intervals to keep the cable in proper contact
with the pipe. Refer to Table 2 below to calculate the num­ber of rolls of attachment tape required based on the pipe
diameter 1.

• If applicable, refer to installation details provided with the

project drawings or contact Thermon for additional infor­mation regarding installation.

2. In addition to the circumferential tape requirements, a
continuous covering of aluminum foil tape may be required
when:

• Spray or foam urethane2 thermal insulation is applied.

• Heat tracing nonmetallic piping.

• Design requirements dictate the use of aluminum tape to

improve heat transfer.

3. Complete splice connections (if required) in accordance
with the installation instructions provided with the splice kit.

4. Install power connection kit in accordance to the detailed
installation instructions provided with the kit.

5. Before making power connections, repeat the megger test
with at least a 500 Vdc megohmmeter (megger) between
the heating cable bus wires and the heating cable metallic
braid. IEEE 515.1 recommends that the test voltage for
polymer insulated heating cables be 2500 Vdc. The mini­mum acceptable level for the megger reading for any
polymer-insulated heat tracing cable is 20 megohms.
(Record 2 on Cable Testing Report)

Temperature Control . . .

1.

When a line sensing controller is specied, the sensor should
be placed at least 90° around the circumference from the
heating cable, or at least 2" (5 cm) from the cable.

Heating Cable vs. Sensor Location

Optional Second

Heating Cable

Temperature

Sensor

90°

2. For pipewall sensing thermostatic control, the heating circuit
is to be connected in series with the control contacts as
shown in illustration below. The pipewall sensing thermostat
may require more than one support point.

Pipewall Sensing Control Connection

L1

L2/N

Power Connection

3. When using an ambient sensing temperature controller, the
mounting location should be representative of the coldest

Temperature Sensor End Termination

Heating Cable

region, and the sensing element should not be exposed to
direct sunlight or any additional heat source.

Ambient Sensing Control Connection

Ambient Sensing Thermostat

Optional Third
Heating Cable

Heating Cable

(Typical)

Notes . . .

1. Table 2 assumes circumferential bands every 12” (30 cm) along the length of the piping.

2. Verify exposure temperature of heating cable versus curing temperature of insulation.

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

Tape

Length

36 yd

60 yd

½"-1" 1¼" 1½" 2" 3" 4" 6" 8" 10" 12" 14" 16" 18" 20" 24" 30"

130' 115' 110' 95' 75' 65' 50' 40' 35' 30' 26' 23' 21' 19' 16' 13'

215' 195' 180' 160' 125' 105' 80' 65' 55' 50' 43' 38' 35' 31' 27' 22'

L1

L2/N

End Termination

Power Connection

Heating Cable

Pipe Diameter in Inches

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Thermal Insulation . . .

1. The need for properly installed and well-maintained thermal
insulation cannot be overemphasized. Without insulation,
heat losses are generally too high to be oset by a conven­tional heat tracing system.

2. In addition to piping and in-line equipment such as pumps
and valves, all heat sinks must be properly insulated. This
includes pipe supports, hangers, anges and, in most cases,
valve bonnets.

3. Regardless of the type or thickness of insulation used, a
protective barrier should be installed. This protects the
insulation from moisture intrusion, physical damage and
helps ensure the proper performance of the heat tracing
system. Seal around all penetrations through the thermal
insulation.

4. After the installation of the thermal insulation and weather
barrier but BEFORE ENERGIZING THE HEATING CIRCUIT,
the megohmmeter test should be repeated. This should call
attention to any damage to the heating cable that may have
occurred during the insulation installation. (Record 3 on
Cable Testing Report)

Final Inspection and Documentation . . .

1. It is recommended that the circuit be temporarily energized
so that the volts, amps, pipe temperature and ambient
temperature may be recorded. This information may be of
value for future reference and should be maintained for the
historical operating data log (Record 4 on Cable Testing
Report).

2. Once power is connected but before putting the system
into operation, verify all heating cable testing and documen­tation have been completed for each heat tracing circuit.
This will ensure that the system has been installed per the

manufacturers recommendations.

The National Electric Code and Canadian Electrical
Code require ground-fault protection be provided
for branch circuits supplying electric heat tracing
on xed outdoor electric de-icing and snow-melt­ing equipment.

5. Apply caution labels to insulation weather barrier at required
intervals along pipe

Thermal Insulation with Weather Barrier

Thermal

Insulation

Temperature

Sensor

Weather

Barrier

Heating Cable

(Typical)

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FLX ™ Cable Testing Report

1. Refer to Thermon FLX Installation Procedures, FORM CPD1018, 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 cables are
printed on the outer jacket with part number, voltage rating and watt output.

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 megohmmeter (megger) between the
heating cable bus wires and the heating cable metallic braid.
IEEE 515.1 recommends that the test voltage for polymer
insulated heating cables be 2500 Vdc. Minimum resistance
should be 20 megohms. (Record 1 on Cable Testing Report.)

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 innity 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 scumarks on the outer jacket will not aect 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 megohmmeter (megger) between the heating cable bus wires and the heating cable metallic braid. IEEE 515.1
recommends that the test voltage for polymer insulated heating cables be 2500 Vdc. Minimum resistance should be 20
megohms. (Record 2 on Cable Testing Report.)

5. After the thermal insulation is installed, the megohmmeter test should be repeated. Minimum resistance should be 20
megohms. (Record 3 on Cable Testing Report.)

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

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, and the test results recorded and
mailed/faxed to:

Thermon Customer Service

100 Thermon Drive
San Marcos, Texas 78666
Fax: [phone]

7

FLX ™ Cable Testing Report

Customer: Contractor:

Address: Address:

Phone No: Phone No.

Project Reference:

Record 1: Prior to Installation

Cable Type:

Heater Length:

Heater Number:

Insulation Resistance M Ohms:

Tested By: Date:

Witnessed By: Date:

Record 2: After Installation

Insulation Resistance M Ohms:

Tested By: Date:

Witnessed By: Date:

Record 3: After Thermal Insulation is Installed

Insulation Resistance M Ohms:

Tested By: Date:

Witnessed By: Date:

Record 4: Final Commissioning

Panel Number:

Breaker Number:

Volts:

Ambient Temperature (deg. F):

Recorded Amps:

Tested By: Date:

Witnessed By: Date:

Other Products . . .

Thermon oers additional cut-to-length cables or

complete turn-key systems for the following
applications:

• Hot Water Temperature Maintenance

• Freezer Floor Frost Heave Prevention

• Tank and Hopper Heating

• Instrument Tubing Bundles

• Control and Monitoring Systems

Thermon . . . The Heat Tracing Specialists

100 Thermon Dr. • PO Box 609 • San Marcos, TX 78667-0609
Phone: [phone] • Facsimile: [phone] • 800-820-HEAT
www.thermon.com In Canada call 800-563-8461

Form CPD1018-0716 © Thermon Manufacturing Co. Printed in U.S.A.