nVent RAYCHEM H61652 WinterGard Mesh Surface Snow Melting System Instruction Manual

WinterGard Mesh

Surface Snow Melting System

Installation and Operation Manual for Surface Snow Melting

IMPORTANT SAFEGUARDS AND WARNINGS

WARNING: FIRE AND SHOCK HAZARD

nVent RAYCHEM WinterGard Mesh Surface Snow Melting Systems must be installed correctly to ensure proper operation and to prevent shock and fire. Read these important warnings and carefully follow all installation instructions.

• Minimum installation temperature of the WinterGard Mesh Surface Snow Melting System is 23°F(-5°C).
• WinterGard Mesh Surface Snow Melting System is rated weather resistant and suitable for installations in wet areas (-WS).
• Approvals and performance of the WinterGard Mesh Surface Snow Melting systems are based on the use of approved components and accessories.
• To avoid damage to the heating system, do not energize it until it has been completely embedded and the installation has been completed.
• Ground fault equipment protection must be used on each branch circuit with this heating system in order to minimize the danger of fire and to comply with the requirements of nVent warranties, agency certifications, and national electrical codes. Arcing may not be stopped by conventional circuit protection.
• Heating wires must be spaced at least 1/2 in (1.3 cm) from any combustible surface.
• Minimum bending radius of the heating wire must not be less than six times its diameter.
• The heating wire must not touch, cross over, or overlap itself.
• De-energize the heating system before installation or servicing.
• The heating system must be properly grounded according to applicable electrical codes.
• Terminations must be kept dry before, during, and after installation.
• Damaged heating systems can cause electrical arcing or fire. If heating wires or terminations are damaged, they must be repaired or replaced. Contact nVent customer service for assistance.
• Rebar, wire mesh or other conductive materials used to support the heating system or to sit above it must be grounded in accordance with CSA Standard C22.1, Section 10 or the National Electrical Code as applicable.
• Megohmmeters operate at high voltage. This voltage is hazardous and possibly lethal. Read and follow all instructions included with the instrument you are using.

CAUTION: a ground fault protection device must be used with this heating device.

1. GENERAL INFORMATION

1.1 Use of the Manual

This manual covers the installation procedures, testing, and maintenance for nVent RAYCHEM WinterGard Mesh Snow Melting Systems, accessories, and controls for surface snow melting in concrete, asphalt, and sand or limestone screenings under paving stones*.

This manual assumes that a proper snow melting or anti-icing design has been completed according to nVent’s recommendations. Only the applications described in this manual are approved by nVent for nVent RAYCHEM WinterGard Mesh Surface Snow Melting Systems and only when used with approved accessories.

The instructions in this manual and the installation instructions included with the control systems, power distribution systems, and accessories must be followed for the nVent warranty to apply.

For design assistance, technical support, or information regarding other applications not shown here, please contact your nVent representative or nVent directly.

nVent
7433 Harwin Drive
Houston, TX 77036
USA

Tel +1.800.545.6258
Fax +1.800.527.5703
thermal.info@nVent.com
nVent.com/RAYCHEM

Important: For the nVent warranty and agency approvals to apply, the instructions that are included in this manual and product packages must be followed.

*Special permission for paver snow melting is required from the Authority Having Jurisdiction.

1.2 WinterGard Mesh Applications

Surface Snow Melting: Surface snow melting systems prevent the accumulation of snow on ramps, slabs, driveways, sidewalks, platform scales, and stairs under typical snow conditions.

Anti-Icing: Anti-icing systems keep the surface temperature above freezing to prevent ice formation.

1.3 Safety Guidelines

As with any electrical equipment, the safety and reliability of any system depends on the quality of the products selected and the manner in which they are installed and maintained. Incorrect design, handling, installation, or maintenance of any of the system components could damage the Surface Snow Melting System and may result in inadequate snow melting, electric shock, or fire. To minimize these risks and to ensure that the system performs reliably, read and carefully follow the information, warnings, and instructions in this guide.

Pay special attention to the following:

• Important instructions are marked Important
• Warnings are marked WARNING

1.4 Electrical Codes

Article 426 of the National Electrical Code (NEC) and Section 62 of the Canadian Electrical Code (CEC) govern the installation of fixed outdoor surface snow melting and de-icing systems. All installations must be in compliance with these and any other applicable national and local codes.

1.5 Approvals

WinterGard Mesh systems are approved for use in nonhazardous areas only.

1.6 Warranty

nVent warrants all nVent RAYCHEM WinterGard Mesh Systems against faulty workmanship and use of defective materials for two (2) years from the date of purchase. This warranty can be amended only by a written instrument signed by a duly authorized officer of nVent. Buyer’s exclusive remedy under this warranty shall be to have nVent, within a reasonable time, repair such goods, or supply replacement goods, or credit Buyer’s account for such goods and accept their return, whichever nVent may elect at its sole discretion. nVent shall in no event be liable for the cost of removal or installation, for loss or damage to or loss of use of facilities or other property, loss of revenue, loss of use of revenue, loss of anticipated profits, or other damages or costs of any kind whatsoever, whether direct, indirect, incidental, or consequential.
Notwithstanding the foregoing, nVent shall have no liability whatsoever unless: (a) Buyer promptly notifies nVent in writing after discovery of an alleged nonconformity and includes a detailed explanation of the alleged nonconformity; (b) buyer promptly returns goods to nVent postage prepaid, at 250 West Street, Trenton, Ontario, K8V 5S2, Canada or 7433 Harwin Drive, Houston, Texas, 77036, USA; and (c) nVent examination of such goods establishes to nVent satisfaction that such alleged nonconformities actually exist and occurred in the cause of proper and normal use and were not caused by accident, misuse, neglect, alteration or improper installation, repair or testing or such other cause outside of the responsibility of nVent under this Limited Warranty. THE FOREGOING WARRANTY IS IN LIEU OF ALL OTHER REPRESENTATIONS, WARRANTIES, OR CONDITIONS, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT, AND OF ANY OTHER OBLIGATION OR LIABILITY ON THE PART OF nVent, WHETHER BY STATUTE, CONTRACT, STRICT LIABILITY, TORT OR OTHERWISE. If the goods are a consumer product in buyer’s jurisdiction, the above exclusion or limitation of incidental or consequential damages and the above disclaimer of implied warranties may not apply. The term of any such implied warranty is limited to the term of this two-year Limited Warranty. Some jurisdictions do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply. This warranty gives consumers specific legal rights, and consumers may also have other rights, which vary by jurisdiction.

1.7 WinterGard Mesh Catalog Numbers

The catalog number for WinterGard Mesh encodes the product characteristics as follows:

WM[a]-[bb][cc]

• WM = WinterGard Mesh
• [a] = Voltage
  • 1 = 120 V
  • 2 = 240 V
• [bb] = Width (ft)
  • 02 = 2 ft
  • 03 = 3 ft
• [cc] = Length (ft)
  • 05 = 5 ft
  • 10 = 10 ft
  • 15 = 15 ft
  • 20 = 20 ft
  • 25 = 25 ft
  • 30 = 30 ft
  • 35 = 35 ft
  • 40 = 40 ft
  • 45 = 45 ft
  • 50 = 50 ft
  • 60 = 60 ft
• Area coverage (ft²) = Width x Length
• Power (W) = Area coverage (ft²) x 50 W/ft²

For example, WM1-0205 is 120 Volts, 2 ft wide, 5 ft long, 10 ft² area, and 500 Watts.

2. REQUIRED PARTS & EQUIPMENT

2.1 Spacer, junction box, supply lead and caution sign

When it is necessary to loosen the heating wire from the mesh, the plastics strips (Model EM2-SPACER-PL) will help maintain the correct spacing 3″ (7.6 cm). For asphalt layer the metal spacer (Model HARD-SPACER-GALV-25MM-25M) should be used. Extension of the cold leads needs to be done in a junction box. The connection between the control panel and the junction box is made by a suitable supply lead.

For installation in asphalt, the sensor cables must be protected by a metal conduit pipe or be laid under the asphalt layer in the substrate underneath. The conduit pipe is sealed at the end so the asphalt cannot seep in. Ensure that the heating wire and the splice and end seal terminations are completely enveloped by the asphalt without air pockets. Allow asphalt to cool to temperature of approximately 212°F (100°C) before pouring it within 30″ (76 cm) of the terminations. This work needs to be done before the asphalt pouring of the entire surface will be executed.

Minimum one snow melt caution sign (Model SMCS or SMCS-CF) should be used per system.

2.2 Controller

nVent offers control units specially designed for the surface snow melting application. They incorporate combined temperature and moisture sensors to ensure efficient operation of the system.

2.3 Panels

nVent offers a range of standard panels specifically designed for the surface snow melting application. Each panel contains a built in control unit, plus circuit breakers and a residual current device (RCD).

2.4 Conduits

Conduits (not included) are required to protect the cold lead and the sensor connection lead.

2.5 Electrical control equipment

If nVent standard panels are not used, addition items will be required to complete the system:

• Contactors
• Circuit breakers
• Residual current device (RCD) 30 mA.

2.6 Storage of WinterGard Mesh

Storage temperature range: -40°F to 113°F (-40°C to 45°C). Store all system elements in a clean, dry place.

2.7 Test equipment

• Ohmmeter
• 2500 Vdc insulation resistance tester (500 Vdc minimum)

3. INSTALLATION GUIDELINES & PROCEDURES

3.1 Area to be heated

Determine the exact area to be heated and consider the following factors:

• Ensure the area to be heated complies with the data in the design instructions. See Table 1 for product selection.
• Establish junction box location(s) and ensure the connection leads are long enough.
• Inspect and clean the substratum before installation, removing sharp objects that can damage the heating element.
• The heating element must not be shortened or altered.

1. Covered area

1. Do not run the heating mat over expansion joints.
2. Covered area
3. Heat at least three feet (one meter) into the covered area, as incoming vehicles can bring in snow.
4. Also heat the drain gutter.
5. Lay the heating cable right up to the drain-off gutter.
6. Also heat the surfaces on which braking will occur, e.g. before a barrier or a magnetic card reader.

3.2 Preparing the Subsurface

WinterGard Mesh should be installed on a stable subsurface. In suspended structures the substratum may consist of finished slabs, prestressed concrete or a suspended structure with poured concrete. WinterGard Mesh can be laid on all subsurfaces.

In the case of poured concrete, ensure that the surface is smooth and all sharp objects are removed. Ramps on a solid substratum do not require additional thermal insulation.

Appropriate preparations should be made for installing the temperature and moisture sensor.

3.3 Conductor Resistance and Insulation Resistance Tests

Test WinterGard Mesh by measuring the conductor resistance and the insulation resistance.

Test the conductor resistance with an ohmmeter. The measured resistance should be within -5% to +10% of the nominal resistance values shown in Table 1.

1. Conductor
2. Cold lead
3. Ohmmeter

Test the insulation resistance with a 2500 Vdc (500 Vdc minimum) insulation resistance tester. The reading should be 100 Mohms or higher.

1. Conductor
2. Cold lead
3. Insulation resistance tester

Record all measured values on the Installation Test Record provided.

Table 1: WinterGard Mesh Product Selection

Catalog #|

Voltage (V)

|

Width (ft)

|

Length (ft)

| Area (ft²)| Resistance (Ω)|

Power (W)

---|---|---|---|---|---|---
WM1-0205|

120

|

2

|

5

| 10| 28.8|

500

WM1-0210|

120

|

2

|

10

| 20| 14.4|

1000

WM1-0215|

120

|

2

|

15

| 30| 9.6|

1500

WM1-0220|

120

|

2

|

20

| 40| 7.2|

2000

WM1-0225|

120

|

2

|

25

| 50| 5.8|

2500

WM1-0230|

120

|

2

|

30

| 60| 4.8|

3000

WM1-0310|

120

|

3

|

10

| 30| 9.6|

1500

WM1-0315|

120

|

3

|

15

| 45| 6.4|

2250

WM1-0320|

120

|

3

|

20

| 60| 4.8|

3000

WM2-0205|

240

|

2

|

5

| 10| 115.2|

500

WM2-0210|

240

|

2

|

10

| 20| 57.6|

1000

WM2-0215|

240

|

2

|

15

| 30| 38.4|

1500

WM2-0220|

240

|

2

|

20

| 40| 28.8|

2000

WM2-0225|

240

|

2

|

25

| 50| 23.0|

2500

WM2-0230|

240

|

2

|

30

| 60| 19.2|

3000

WM2-0235|

240

|

2

|

35

| 70| 16.5|

3500

WM2-0240|

240

|

2

|

40

| 80| 14.4|

4000

WM2-0245|

240

|

2

|

45

| 90| 12.8|

4500

WM2-0250|

240

|

2

|

50

| 100| 11.5|

5000

WM2-0260|

240

|

2

|

60

| 120| 9.6|

6000

WM2-0310|

240

|

3

|

10

| 30| 38.4|

1500

WM2-0320|

240

|

3

|

20

| 60| 19.2|

3000

WM2-0325|

240

|

3

|

25

| 75| 15.4|

3750

WM2-0330|

240

|

3

|

30

| 90| 12.8|

4500

WM2-0340|

240

|

3

|

40

| 120| 9.6|

6000

3.4 WinterGard Mesh Installation

All connections and electrical testing should be carried out by a qualified electrician. For irregularly shaped areas, it is acceptable to cut the mesh and adjust the heating element position in order to achieve good coverage; however…

• The heating element must not be cut or damaged
• The heating element must not be crossed over itself
• The heating element must not be installed within 3″ (7.6cm) of another section of heating element
• WinterGard Mesh must not installed across expansion joints or across separate concrete slabs

Minimum wire spacing is 3″ (7.6cm)

The mesh must be secured to the underlaying surface to prevent movement during the installation. The cold lead cable should be protected in a conduit. The entire length of heating wire should be covered by wet sand-cement mixture, screed, dry sand, or asphalt depending on the selected top surface.

Installation Overviews

Installation in cement screed or asphalt

1. WinterGard Mesh
2. Temperature and moisture sensor
3. Soil
4. Concrete/compacted substrate
5. Cement screed ground

Installation under pavers

1. WinterGard Mesh
2. Temperature and moisture sensor
3. Stones / paver
4. Soil ground
5. Sand bed / or cement / sand mixture

Installation under asphalt

1. WinterGard Mesh
2. Asphalt layer 1.22″
3. Temperature and moisture sensor
4. Soil
5. Concrete/compacted substrate
6. Cement screed ground

• Do not use any heavy equipment, machinery, or vehicles on top of an exposed WinterGard Mesh system.
• If the heating element needs to be loosened from the mesh to achieve good coverage, the installer should use spacers to keep the heating element spacing consistent.
• For installation under pavers (stone or brick), ensure that there is a solid base of 4″ to 8″ (102 mm to 203 mm) of crushed rock aggregate base and that it is tamped down and prepared for the mortar pour.

Step 1: Install the sensor lead

The sensor lead should be routed through a metal conduit in the layer below the heating system.

1. Concrete/ Screed/ Asphalt
2. Sensor housing/or wooden block
3. Heating cable
4. Conduit

Step 2: Make provisions for installation of the temperature/ moisture sensor

For sensors comprising a separate housing and sensor, install only the housing at this stage. For sensors without a separate housing, use a spacer the same size as the sensor (such as a wooden block) to create a void for the sensor to be installed into later.
The sensor housing or spacer should be placed mid-way between heating elements in an open area, away from trees, bushes, or other obstructions that would prevent precipitation from falling directly on the sensor.
Support the sensor housing or spacer so that it will be vertical and level with the lowest point of the adjacent surface.

1. Heating cable
2. Sensor

Step 3: Complete the layer below the heating system

Install the subsurface materials in accordance with applicable building and electrical codes.

1. Level with the lowest adjacent surface
2. Surface
3. Sensor
4. Filling material
5. Sub surface

Step 4: Perform Conductor Resistance and Insulation Resistance Tests as described in section 3.3

Carry out the resistance tests on each circuit to ensure the product is within spec prior to installation.

Record the values for each circuit on the Installation Test Record.

Step 5: Install WinterGard Mesh throughout the heated area

1. Laying spacing as given
2. Heating cable
3. Spacer
   (prestamped plastic strip, for asphalt metal VIA-Spacer)

Step 6: Inspect the heating system

a) Visually check the heating system for damage.
b) Verify that any loose heating cable is secured with spacers.
c) Verify that the correct cable spacing of 3” (10 cm) has been maintained and that the heating cable is being kept away from sharp edges and not crossing expansion joints or across separate slabs.
d) Verify that the heating system is installed at the correct depth throughout the heated area.
e) Inspect the connection leads for correct installation.

Step 7: Complete a detailed sketch of the layout

Record the layout of each circuit, with particular reference to the position of the connection leads.

Step 8: Perform conductor resistance and insulation resistance tests as described in section 3.3

Carry out the resistance tests on each circuit to detect any damage that may have occurred during installation.

Record the values for each circuit on the Installation Test Record.

Step 9: Install the surface materials

Install concrete, asphalt, or pavers in accordance with applicable building and electrical codes.

Step 10: Perform conductor resistance and insulation resistance tests as described in section 3.3

Carry out the resistance tests on each circuit to detect any damage that may have occurred after installation.

Record the values for each circuit on the Installation Test Record.

Step 11: Connect and install the moisture sensor

Install the moisture sensor in accordance with the manufacturer’s instructions.
Ensure the sensor is mounted vertically and supported at the correct height so the top of the sensor is level with the lowest adjacent surface.

1. Level with the lowest adjacent surface

Step 12: Connect and install the temperature sensor

Install the temperature sensor in accordance with the manufacturer’s instructions.

Step 13: Complete wiring and install control and monitoring equipment

Install panels, control units, thermostats and manual control equipment in accordance with the manufacturers’ instructions.

Step 14: Perform conductor resistance and insulation resistance tests as described in section 3.3

Carry out the final resistance tests on each circuit prior to powering up the system.

Record the values for each circuit on the Installation Test Record.

Step 15: Perform final system inspection and tests

a) Inspect all wiring for conformance to design drawings.
b) Verify that all protection devices have the correct rating.
c) Perform controller checks in accordance with the manufacturer’s instructions.
d) Complete required testing in accordance with applicable building and electrical codes.

Step 16: Documentation

The installer must supply the operator/owner with the layout drawing and a copy of the Installation Test Record.

4. SYSTEM OPERATION

Operate the system in accordance with the control and monitoring instructions. Max. exposure temperature for WinterGard Mesh: -149°F (-65°C) (for asphalt pouring, short term exposure up to 464°F (240°C) is allowed).

5. SYSTEM MAINTENANCE

The system has no moving parts and therefore requires minimum maintenance. Refer to and comply with applicable codes and requirements for the maintenance of electrical equipment. Circuit breakers should be checked periodically. Residual current devices (RCD) should be tested at least once annually. Periodically inspect the system controls by operating them to ensure that they function correctly.

6. SYSTEM TROUBLESHOOTING

Trouble Shooting Guide

WARNING: Isolate supply before working on any part of the electrical system.

Problem A: Over-current protection (circuit breaker) trips or blows

Electrical fault at:

• connection lead
• damaged heating cable

| Locate and rectify the fault and reset or replace protection.
Protection undersized| Re-establish what the current loads are going to be and install new protection (NB: if protection is replaced, ensure it is compatible with the supply cable).
Defective protection| Replace

Problem B: Residual current device trips

necessary.
Perform an insulation resistance test.
Earth fault at:

• connection 
• damaged heating cable

| Locate and rectify the fault and reset or replace rcd.
Leakage current too high:
power cable or heating cable too long| Correct problem and re-design.
Contactor bouncing| Replace with higher quality contactor
Voltage spikes in power supply network| Reset rcd. If condition persists, use clean power supply.
Defective rcd| Replace

Problem C: Ice/snow not melting

Loss of supply current due to over-currentor residual current device operating.| Follow procedures outlined in A and B above.
Loss of supply cable continuity| Locate and rectify fault.
Incorrect setting or operation of system controls| Replace
Incorrect contactor sizing or damaged contactor| Rectify

Problem D: Ice/snow begins to melt, but system turns off too soon

or set system controls correctly.

nVent.com/RAYCHEM

North America
Tel +1.800.545.6258
Fax +1.800.527.5703
thermal.info@nVent.com

Europe, Middle East, Africa
Tel +32.16.213.511
Fax +32.16.213.604
thermal.info@nVent.com

Asia Pacific
Tel +86.21.2412.1688
Fax +86.21.5426.3167
cn.thermal.info@nVent.com

Latin America
Tel +1.713.868.4800
Fax +1.713.868.2333
thermal.info@nVent.com

nVent.com/RAYCHEM

©2022 nVent. All nVent marks and logos are owned or licensed by nVent Services GmbH or its affiliates. All other trademarks are the property of their respective owners.
nVent reserves the right to change specifications without notice.

RAYCHEM-IM-H61652-WinterGardMesh-ML-2210

References

• Electrical Heat Tracing | Heat Tracing | nVent RAYCHEM

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