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Symptom
Power output appears
EN
correct but snow and ice
is slow to melt.
CF
Power output is zero or
incorrect
IMPORTANT: If the corrective actions above do not resolve the problem, contact your nVent representative for further assistance.
7. INSTALLATION AND INSPECTION RECORD
Facility
Test Date:
Circuit number:
Mesh catalog number:
Controllers:
Temperature setting if applicable:
Commission
Inspection date:
Visual inspection
Confirm 30-mA ground-fault device (proper rating/function)
Visual inspection inside connection boxes for overheating, corrosion, moisture, loose connections, and other problems.
Proper electrical connection
Check controllers for moisture, corrosion, setpoint, switch operation.
Insulation resistance test
Conductor to ground wire
Continuity (Resistance) Test
Conductor to conductor
Power check
Circuit voltage
Panel
Circuit amps after 5 minutes
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nVent.com/RAYCHEM
Probable Causes
1. Slab temperature sensor or slab sensing thermostat
set incorrectly.
2. Thermal time delay.
3. Weather conditions too severe for design.
4. Inadequate watt density (W/sq ft; W/sq m).
5. Wrong WinterGard Mesh installed.
1. Snow melting controller inoperative.
2. Slab sensing thermostat inoperative.
3. Slab sensing thermostat wired in the normally open
(N.O.) position.
4. No input voltage.
5. Broken or damaged heating wire, cold lead, or hot/
cold joint.
6. Circuit breakers tripped.
7. Improper voltage used.
8. Wrong WinterGard Mesh installed.
9. Sensors wired to the incorrect terminals or are not
making contact.
M-Ohms
Test #1 before installation
500 Vdc
1000 Vdc
2500 Vdc
Ohms
Test #1 before installation
(Vac)
(Amps)
Corrective Action
(1)
Set sensor control or thermostat to 50°F (10°C).
(2)
WinterGard Mesh not energized soon enough.
Check system controls. Adjust or modify
operation.
(3)
After snowfall ceases, manually energize
system to melt remaining snow. (A typical
Surface Snow Melting System is not designed
to effectively melt all snow during the severest
storms).
(4,5) Verify installation as per design. Contact nVent
for assistance.
(1)
Verify electrical connections to snow melting
controller and sensor, verify supply voltage to
controller, verify operation, and repair or replace
controller or sensor if necessary.
(2)
Verify electrical connections to thermostat,
verify operation, and repair or replace
thermostat if necessary.
(3)
Confirm wiring using the normally closed (N.C.)
terminals so that contacts close with falling
temperature.
(4)
Repair electrical supply lines and equipment.
(5)
Repair or replace heating wire or cold lead.
(6)
See above symptom under "Circuit breaker
trips."
(7)
Verify voltage and connect to proper voltage,
if necessary.
(8)
Verify installation as per design. Contact nVent
for assistance.
(9)
Verify sensors are wired to the correct terminals
and the conductors are making contact.
Test #2 during installation
Test #3 after installation
Test #2 during installation
Test #3 after installation
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