Installation Manual

3
4.0 Installation for Snow Melting
4.1 Control of Snow Melting System
A control suitable for Snow Melting systems with pavement mounted or aerial
mounted sensor should be used for Snow Melting applications, when not using a
Timer.
4.2 Electrical Provisions for the Systems
The National Electric Code requires that the heating cables and mats must be
supplied power by a GFEP (30mA) protected circuit.
The Snow Melting system installation wiring shall be in accordance with the National
Electric Code and prevailing local codes.
The snow / moisture sensor cable and the Heating Cable cold leads shall be routed
to the power connection box in separate conduits.
Breaker Size (Amps) Max Design Load (Amps)
40 32
30 24
20 16
15 12
2’ (61cm)
or
3’ (91cm)
Length 5’ (152cm) min 50’ (1524cm) max
20’ (610cm) Cold Lead
Outer Sheath PVC/Pololefin
Polyester Sheath
Metal Sheath (Copper/Galvanised Steel/Cladded Steel)
Primary Insulation (Fluoropolymer)
Heating Conductor (Solid/Multistrand)
10"
(251mm)
3"
(8cm)
20’ (610cm)
Cold Lead
SENSOR
HEATING
CABLE
FLOOR
1/4” (6mm)
Twin-conductor
Heating Cable
HEATING SYSTEM
THERMOSTAT
SNOW
SENSOR
SLAB TEMP HIGH
LIMIT SENSOR
(IF APPLICABLE)
SNOW MELT MAT AND CABLE
120 VAC SUPPLY
110V / 230V AC SUPPLY
120 VAC
240 VAC
277 VAC
SUPPLY
RELAY
PANEL
CONTROL
PANEL
SENSOR
HEATING
CABLE
FLOOR
SNOW MELT MAT
THERMOSTAT
P N E
2.5” in (6.3cm) maximum
thickness brick or concrete
paver
1.5” sand, stone
dust or mortar
Plastic tie wrap
4 in (10) or 6 in (15) square 10
gauge wire mesh
Level of
heating
cable
2” (5 cm)
3” (7.6 cm)
8”-12” crushed
rock aggregate
Right
hot/cold joints 6
in (15 cm) apart
and 6 in (15 cm)
from slab edge
Wrong
hot/cold joints
installed on
slab edge
Wrong
hot/cold joints
bunched
concrete wall
Junction box mounted on
inside wall
Control joint
Concrete
Heating cable secured to
rebar with plastic tie wraps
Steel bar
3”
3”
Cable identification tag
(within 3 in (7.5cm) of NPT
connector)
Cold lead
Conduit
Expansion joint
Heated Slab
Conduit
Hot/Cold
joint
Heating
cable
Cold leads protected with 1-1/2in (3.8cm)
minimum nonmetallic conduit
where they emerge from slab
Topping 2 in (5.0 cm)
minimum to 3 in (7.5 cm)
maximum thickness
Dimension B must not
exceed 6 in (15 cm)
Dimension A must not
exceed 3 in (7.5 cm)
If dimension C exceeds 3
in(10 cm) an additional run
of cable must be used
B
Conduit for slab temperature sensor
Corner rounded off to
prevent cable damage
1.2 in (1.3 cm) wide steel
prepunched strapping
Wrong
cold joints
unche
Wrong
cold joints
stalle
slab
Cable must be at least 4 in
(10 cm) from rail post
Cable must be at least 4 in
(10 cm) from edge
C
A
Expansion joint
Concrete
Heating cable secured to
rebar with plastic tie wraps
Steel bar
3”
3”
HOUSE
DRIVEWAY
RELAY
J-BOX