SnoTraceTM RGS
Snow and Ice Melting for Roof and Gutters
INSTALLATION PROCEDURES
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SnoTraceTM RGS
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Refer to the “SnoTrace RGS Cable Testing Report” for required
recording of test data and circuit information.
A. 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 Report Form.)
Connect the positive lead of the megger to the cable
bus wires and the negative lead to the metallic braid.
4. Begin installation at power connection point. Junction box
(supplied by contractor) shall be NEMA 4, UL Listed
weatherproof and should be located and mounted in
sheltered area.
5. Form a drip loop with the heating cable as it leaves the
junction box. Cable should be anchored with a RG-CMC
cable clip as close as possible to the junction box, after the
drip loop.
6. Once the installation is complete, 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.
Report Form.)
(Record 2 on
CAUTICAUTI
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CAUTICAUTI
cable while it is on reel or in shipping carton.cable while it is on reel or in shipping carton.
cable while it is on reel or in shipping carton.
cable while it is on reel or in shipping carton.cable while it is on reel or in shipping carton.
B. Installation of Cable . . .
1. Snow melting cable systems must be installed in accordance with Article 426 of the National Electrical Code as
well as any applicable local codes. Review the requirements
prior to installation.
2. The layout of heating cable on roof and gutters will be
dependant on roof material, roof pitch, amount of roof
overhang, gutter layout or gutter width. The amount of
cable required can be calculated using the Roof and Gutter
Design Guide.
3. Gutters and downspouts should be free from debris. All
sharp edges that may come in contact with the heating
cable should be flattened, smoothed or otherwise protected to prevent possibility of damage to cable.
T connect power to heatingT connect power to heating
O N
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T connect power to heating
O NO N
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T connect power to heatingT connect power to heating
7. To prevent accumulation of moisture inside of the junction
box, use the RGS-CFK heater cable circuit fabrication kit
that includes a strain relief fitting and moisture barrier
grommet.
8. Refer to the Circuit Fabrication Kit instructions for details
on making proper heater cable end terminations.
9. If junction box will be mounted to vertical wall or underside
of sloped roof overhang, locate heating cable termination
kit on lower side of junction box.
10. ELECTRIC HEAT TRACING CAUTION LABELS must be
installed on circuit breaker panels, contactor panels and
junction boxes.
11. Before putting the system into operation, make sure the
heating cables have been tested and that the documentation has been completed for each heat tracing circuit. This
will ensure that the system has been installed per
manufacturer’s recommendations.
Form.)
TT
he National Electric Code Article 426.28,he National Electric Code Article 426.28,
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he National Electric Code Article 426.28,
TT
he National Electric Code Article 426.28,he National Electric Code Article 426.28,
requires ground-fault protection be providedrequires ground-fault protection be provided
requires ground-fault protection be provided
requires ground-fault protection be providedrequires ground-fault protection be provided
for branch circuits supplying electric heatfor branch circuits supplying electric heat
for branch circuits supplying electric heat
for branch circuits supplying electric heatfor branch circuits supplying electric heat
tracing on fixed outdoor electric de-icing andtracing on fixed outdoor electric de-icing and
tracing on fixed outdoor electric de-icing and
tracing on fixed outdoor electric de-icing andtracing on fixed outdoor electric de-icing and
snow-melting equipment.snow-melting equipment.
snow-melting equipment.
snow-melting equipment.snow-melting equipment.
(Record 3 on Report
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SnoTraceTM RGS
TM
C. Heating Cable Layout - Roof Overhang Only . . .
1. Refer to the RGS Design Guide to determine appropriate
heating cable lengths required, as well as spacing pitch
required for various overhang distances and roof types.
2. The attachment clips should be anchored to the roof/fascia
with fasteners or adhesive suited for the roof and the
weather. A waterproofing sealant should be used wherever
screws penetrate the roof or fascia.
3. Where large roof areas will be present above the heating
cable a snow fence should be installed to prevent damage to
the cable from sliding snow and ice.
D. Heating Cable Layout - Gutter and Downspouts Only . . .
1. Refer to the RGS Design Guide to determine appropriate
heating cable lengths required for gutters and downspouts.
2. The attachment clips should be anchored to the fascia/
gutter edge with fasteners or adhesive suited for the roof
and the weather. A waterproofing sealant should be used
wherever screws penetrate the gutter or fascia.
Pitch
RG-CRF
AL-20P
RG-CRF
RG-CRF
RG-CRF
3. Heating cable should be attached to the bottom of the
gutter with aluminum tape. Be sure the bottom surface of
the gutter is clean to promote maximum adhesion of the
tape. Heating cable in the downspouts should not extend
past the downspout opening to prevent vandalism.
4. Protect heating cable from sharp edges of gutter and
downspouts.
E. Heating Cable Layout - Roof Overhang Plus Gutter and
Downspouts . . .
1. Refer to the RGS Design Guide to determine appropriate
heating cable lengths required.
2. The attachment methods outlined in sections C and D
would apply to installing heating cable on both roof
overhang and gutter/downspout areas.
RG-DCH
RG-DCH
RG-CRF
RG-CRF
RG-CRF
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INSTALLATION PROCEDURES
Alternate Roof Types…
SnoTrace RGS on Membrane Type Roofs
Due to the design of membrane type roofs, the methods typically used to secure electric heating cable to the roof may not
be suitable. The best alternative is to construct “loops” approximately 2" x 10" from the same material as the membrane
and attach these loops to the
roof at the points where
the cable will pass and
require anchoring, using the same adhesive
as used on the roof.
Typically these anchors will be required
every two feet along
the length of the cable
or wherever the cable
changes direction. The sketch at
right shows a typical loop with heating cable passing through it.
Allow sufficient room in the loop for the cable to pass without
binding.
The location of the cable and loops should be coordinated between the roofing and electrical contractors in accordance with
design layout provided by the engineer and project manager.
Using the loop method for attaching the heating cable to the
roof will eliminate the need to penetrate the roof membrane
with fasteners.
SnoTrace RGS on Copper Type Roofs
The standard RGS mounting clips and tape are not compatible
with copper roofing and copper gutters. The best alternative is
to use a plastic cable mounting plate along with a cable tie
wrap. The materials in the mounting plates, adhesives and tie
wraps should be rated for outdoor use. These should be
placed in the same spacing as used on the RG-CRF and RGCMC clips for roof use. In gutters, the cable attachments
should be no more than two feet apart. These types of mounts
are not carried by Thermon, but are available from suppliers of
general conduit attachment items.
Please contact Thermon for additional information and design
assistance for other roof types.
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SnoTrace ™ RGS ™ Cable Testing Report
1. Refer to Thermon RGS Installation Procedures, FORM CPD1020, 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.
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.
(Record 1 on Report Form.)
4. After installation is complete, visually inspect cable for any damage incurred during installation. 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 Report Form.)
5. Once 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 10 minutes. Record the ambient temperature, measure and record the circuit(s)
voltage and current.
(Record 3 on Report Form.)
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: 512-754-2420
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SnoTrace ™ RGS ™ 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: Final Commissioning
Panel Number:
Breaker Number:
Volts:
Ambient Temperature (deg. F):
Recorded Amps:
Tested By: Date:
Witnessed By: Date:
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Other Products . . .
Thermon offers additional cut-to-length cables or
complete turn-key systems for the following
applications:
• Hot Water Temperature Maintenance
• Pipe Heating
• Freezer Floor Frost Heave Prevention
• Rail and Rail Switch Heating
• Tank and Hopper Heating
• Instrument Heating Systems
• Control and Monitoring Systems
100 Thermon Dr. • PO Box 609 • San Marcos, TX 78667-0609
Phone: 512-396-5801 • Facsimile: 512-396-3627 • 800-820-HEAT
www.thermon.com In Canada call 800-563-8461
FORM CPD1020-0805 © Thermon Manufacturing Co. Printed in U.S.A.
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