SURFACE SNOW MElTING AND ANTI

SURFACE SNOW MElTING AND ANTI
Pipe Freeze Protection
and Flow Maintenance
Freezer Frost
Heave Prevention
Raychem ElectroMelt heating cable systems can be used as a surface snow melting
system when installed in concrete pavement or under paving stones. It can also be
used as an anti-icing system but only when installed in concrete pavement.
Surface Snow
Melting – ElectroMelt
Introduction
Surface Snow
Melting – MI
Contents
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
How to Use this Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Safety Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Typical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Self-Regulating Heating Cable Construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Approvals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Surface Snow Melting and Anti-Icing Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Surface Snow Melting and Anti-Icing Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Design Step by Step. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Step 1 Determine design conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Step 2 Select the heating cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Step 3 Determine the required watt density . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Step 4 Determine heating cable spacing. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Step 5 Determine the total area to be protected. . . . . . . . . . . . . . . . . . . . . . 13
Step 6 Determine heating cable length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Step 7 Determine the electrical parameters. . . . . . . . . . . . . . . . . . . . . . . . . 16
Step 8 Select the connection kits and accessories. . . . . . . . . . . . . . . . . . . . 18
Step 9 Select the control system and power distribution. . . . . . . . . . . . . . . 21
Step 10 Complete the Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
ElectroMelt System Surface Snow Melting and Anti-Icing Design Worksheet. . . . . 28
Roof and Gutter
De-Icing
This step-by-step design guide provides the tools necessary to design a Raychem
ElectroMelt heating cable surface snow melting and anti-icing system. For other
applications or for design assistance, contact your Pentair Thermal Management
representative or phone Pentair Thermal Management at (800) 545‑6258. Also, visit
our web site at www.pentairthermal.com.
Fire Sprinkler System
Freeze Protection
Surface snow melting and
anti-icing – electromelt
Important: ElectroMelt is not approved for use in asphalt.
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
1 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Floor Heating
If your application conditions are different, or if you have any questions, contact your
Pentair Thermal Management representative or contact Pentair Thermal
Management directly at (800) 545‑6258.
Surface snow melting and anti-icing – electromelt
How to Use this Guide
This design guide presents Pentair Thermal Management’ recommendations for
designing an ElectroMelt surface snow melting and anti-icing system. It provides
design and performance data, electrical sizing information, and heating-cable layout
suggestions. Following these recommendations will result in a reliable, energyefficient system.
Follow the design steps in the section “Surface Snow Melting and Anti-Icing Design,”
page 6 and use the “ElectroMelt System Surface Snow Melting and Anti-Icing
Design Worksheet,” page 28 to document the project parameters that you will
need for your project’s Bill of Materials.
Other Required Documents
This guide is not intended to provide comprehensive installation instructions. For
complete ElectroMelt surface snow melting system and anti-icing installation
instructions, please refer to the following additional required documents:
• ElectroMelt System Installation and Operation Manual (H58086)
• Additional installation instructions that are included with the connection kits,
thermostats, controllers and accessories
If you do not have these documents, you can obtain them from the Pentair Thermal
Management web site at www.pentairthermal.com.
For products and applications not covered by this design guide, please contact your
Pentair Thermal Management representative or call Pentair Thermal Management
directly at (800) 545-6258.
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 system and may result in inadequate
performance, overheating, 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.
This symbol identifies important instructions or information.
This symbol identifies particularly important safety warnings that must be
followed.
WARNING: To minimize the danger of fire from sustained electrical arcing if
the heating cable is damaged or improperly installed, and to comply with the
requirements of Pentair Thermal Management, agency certifications, and national
electrical codes, ground-fault equipment protection must be used on each heating
cable branch circuit. Arcing may not be stopped by conventional circuit protection.
Warranty
Pentair Thermal Management’ standard limited warranty applies to Raychem Snow
Melting Systems.
An extension of the limited warranty period to ten (10) years from the date of
installation is available, except for the control and distribution systems, if a properly
completed online warranty form is submitted within thirty (30) days from the date of
installation. You can access the complete warranty on our web site at
www.pentairthermal.com.
2 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
System Overview
Typical System
A typical system includes the following:
Fire Sprinkler System
Freeze Protection
The Raychem ElectroMelt system provides surface snow melting and anti-icing for
concrete surfaces and pavers. The ElectroMelt system uses a self-regulating heating
cable that reduces heat output automatically as the pavement warms, resulting in
lower energy use, and eliminating the possibility of overheating. The system includes
heating cable, connection kits, junction boxes, a control system and sensors, power
distribution panels, and the tools necessary for a complete installation.
Pipe Freeze Protection
and Flow Maintenance
System Overview
• ElectroMelt self-regulating heating cable
Roof and Gutter
De-Icing
• Connection kits and accessories
• Snow controller and sensors
• Power distribution
Power Distribution Panel
Aerial Snow Sensor
Surface Snow
Melting – MI
Snow Controller
AP
AP
SS-4
4
Sno
w/Ic
e Me
ltin
gC
Con
ont
tr
roll
olle
err
SUP
HEA PLY
USE TER : 277
ONL : 37
3777 VAC
Y COP
VAC , 50/6
SEE SUF PER , 40 AMP0HZ
INS FICI CON . Z, 35V
TAL ENT DUC MAX A
LAT AMP TOR RES
ION ACI S
IS
INS TY. HAV
TRU
ING
CTIO
NS
DAN
Leth GER
qual al vol OF
ified tage
LEECT WAR
s
requpers are RICAL NIN
ired onne presen SHOG
to l only. t ben CK
de-e Mor
nerg e eath OR LCT
ize than this E ROC
this one cove
cont disc r. ServUTION
rol on icee
for nect
serv may by
icing
. be
SUP
PLY
SN
SNO
OW
W
HEA
TER
TER
GR
OU
ND
FAU
HEA
LT
TER
TER
CYC
RES
CYCL
LEE
ET
ET
TES
T GR
OU
ND
FAU
LT
HO
LD
ON
TIM
E(HR
S)
Power Connection and End Seal
Surface Snow
Melting – ElectroMelt
Caution Sign
Pavement Snow Sensor
Heating Cable
Freezer Frost
Heave Prevention
Heating Cable Splice
Expansion Joint Kit
Floor Heating
Fig. 1 Typical ElectroMelt system
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
3 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Self-Regulating Heating Cable Construction
The ElectroMelt self-regulating heating cable is embedded in concrete pavement
to melt snow and ice that might otherwise accumulate on the surface. The heating
cable responds to the local concrete temperature, increasing heat output when
concrete temperature drops and decreasing heat output when concrete temperature
rises. The self-regulating heating cable cannot overheat and destroy itself, even
if overlapped in the concrete, and therefore does not require the use of overlimit
thermostats.
Modified polyolefin outer jacket
Tinned-copper braid
Modified polyolefin inner jacket
Self-regulating conductive core
Nickel-plated copper bus wire
Fig. 2 ElectroMelt heating cable construction
With self-regulating technology, the number of electrical paths between bus wires
changes in response to temperature fluctuations. As the temperature surrounding
the heater decreases, the conductive core contracts microscopically. This contraction
decreases electrical resistance and creates numerous electrical paths between the
bus wires. Current flows across these paths to warm the core.
As the temperature rises, the core expands microscopically. This expansion
increases electrical resistance and the number of electrical paths decreases. The
heating cable automatically reduces its output.
At high temperature,
there are few conducting paths and output is
correspondingly lower,
conserving energy
during operation.
The following graphs illustrate the response of self-regulating heating
cables to changes in temperature. As the temperature rises, electrical
resistance increases, and our heaters reduce their power output.
re
g
Se
Power
ul
at
in
g
Constant wattage
lf-
At moderate temperature,
there are fewer conducting
paths because the heating
cable efficiently adjusts by
decreasing output, eliminating
any possibility of overheating.
Resistance
At low temperature,
there are many
conducting paths,
resulting in high output
and rapid heat-up. Heat
is generated only when it
is needed and precisely
where it is needed.
Constant wattage
Se
lf-
re
g
ul
at
ing
Temperature
Temperature
Fig. 3 Self-regulating heating cable technology
4 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Approvals
The ElectroMelt surface snow melting and anti-icing system is UL Listed and CSA
Certified for use in nonhazardous locations.
Surface Snow Melting and Anti-Icing Applications
SURFACE SNOW MELTING
Surface snow melting systems prevent the accumulation of snow on ramps, slabs,
driveways, sidewalks, platform scales, and stairs under most snow conditions.
Fire Sprinkler System
Freeze Protection
-ws
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Applications
Roof and Gutter
De-Icing
ANTI-ICING
Anti-icing systems keep the surface temperature above freezing at all times to
prevent ice formation. Anti-icing applications require a higher watt density and
longer hours of operation than a surface snow melting system.
Application Requirements and Assumptions
The design for a standard surface snow melting and anti-icing application is based
on the following:
The following are examples of applications not addressed in this design guide:
Surface Snow
Melting – ElectroMelt
For products and applications not covered by this guide, contact your Pentair
Thermal Management representative for design assistance. Using proprietary
computer modeling, Pentair Thermal Management can design the appropriate
system for these applications.
Surface Snow
Melting – MI
Heating cable
•Secured to reinforcement steel or
mesh
•Located 1 1/2 to 2 inches (4 to 6 cm)
below finished surface
Pavers
Heating cable
•Concrete pavers 1 to 1 1/2
•Secured to mesh
(2.5 to 4 cm) inches thick
•Embedded in concrete or mortar base
•Placed on concrete or mortar base on
below the pavers
grade
Reinforced Concrete
• 4 to 6 inches (10 to 15 cm) thick
•Placed on grade
•Standard density
• Concrete thinner than 4 inches (10 cm)
Freezer Frost
Heave Prevention
• Concrete thicker than 6 inches (15 cm)
• Lightweight concrete
• Concrete with pavers thicker than 1 1/2 inches (4 cm)
• Ramps and walkways with air below
• Concrete without reinforcement
• Retrofitting of heating cable to existing pavement
• Pavers composed of material other than concrete
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
5 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Surface Snow Melting and Anti-Icing Design
This section details the steps necessary to design your application. The examples
provided in each step are intended to incrementally illustrate sample designs from
start to finish. As you go through each step, use the “ElectroMelt System Surface
Snow Melting and Anti-Icing Design Worksheet,” page 28 to document your project
parameters, so that by that end of this section you will have the information you need
for your Bill of Materials.
Design Step by Step
Your system design requires the following essential steps:
 Determine design conditions
 Select the heating cable
 Determine the required watt density
 Determine heating cable spacing
 Determine the total area to be protected
 Determine heating cable length
 Determine the electrical parameters
 Select the connection kits and accessories
 Select the control system and power distribution
 Complete the Bill of Materials
6 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Surface Snow Melting
and Anti-Icing
Step 1 Determine design conditions
1. Determine design
conditions
3. Determine the
required watt density
• Application (surface snow melting or anti-icing)
• Environment
–– For surface snow melting: Geographical location
–– For anti-icing: Minimum ambient temperature and average wind speed
4. Determine heating
cable spacing
• Paving material
5. Determine the total
area to be protected
• Size and layout
6. Determine heating
cable length
8. Select the connection
kits and accessories
–– Slab surface area
–– Ramp surface area
–– Stairs
Roof and Gutter
De-Icing
7. Determine the
electrical parameters
Fire Sprinkler System
Freeze Protection
2. Select the heating
cable
Collect the following information to determine your design conditions:
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
-- Number of stairs
-- Width of stair
9. Select the control
system and
power distribution
-- Riser height
10. Complete the Bill
of Materials
-- Landing dimensions
-- Depth of stair
–– Wheel tracks
Surface Snow
Melting – MI
-- Track length
–– Concrete joints
–– Surface drains
–– Location of area structures
–– Other information as appropriate
• Supply voltage
• Automatic or manual control method
Surface Snow
Melting – ElectroMelt
Note: Drainage must be a primary concern in any snow melting system design.
Improper drainage can result in ice formation on the surface of the heated area once
the system is de-energized. Ice formation along the drainage path away from the
heated area may create an ice dam and prohibit proper draining. If your design
conditions may lead to drainage problems, please contact Pentair Thermal
Management Technical Support for assistance.
Prepare Scale Drawing
Freezer Frost
Heave Prevention
Draw to scale the snow melting area and note the rating and location of the voltage
supply. Include stairs and paths for melting water runoff. Show concrete joints,
P
Power connection
surface
drains,
and location of area structures including post installations for
railings,
permanent
benches, and flagpoles. Measurements for each distinct section
E
End
seal
of the
melting
application,
including stairs, will allow for an accurate system
S snow
Splice
design, including control configuration. Use these symbols to indicate the heating
cable expansion and crack-control joints:
Expansion joint
Crack-control joint
Floor Heating
Expansion joint kit
Fig. 4 Design symbols
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
7 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Example: Surface Snow Melting System
Application
Surface snow melting
Geographical location
Buffalo, NY
Size and layout
80 ft x 50 ft (24.4 m x 15.2 m)
Paving material
Concrete slab
Stairs:
Number of stairs
10
Width of stair
5 ft (1.5 m)
Riser height
6 in (15 cm)
Depth of stair
12 in (30 cm)
Supply voltage
277 V
Phase
Single-phase
Control method
Automatic snow melting controller
Example: Anti-Icing System
Application
Anti-icing
Minimum ambient temperature
10°F (–12°C)
Average wind speed
20 mph (32 kmph)
Size and layout
80 ft x 50 ft (24.4 m x 15.2 m)
Paving material
Concrete slab
Stairs:
Number of stairs
10
Width of stair
5 ft (1.5 m)
Riser height
6 in (20 cm)
Depth of stair
12 in (30 cm)
Supply voltage
277 V
PhaseSingle-phase
Control method
Surface Snow Melting
and Anti-Icing
1. Determine design
conditions
2. Select the heating
cable
3. Determine the
required watt density
4. Determine heating
cable spacing
5. Determine the total
area to be protected
6. Determine heating
cable length
7. Determine the
electrical parameters
8. Select the connection
kits and accessories
9. Select the control
system and
power distribution
10. Complete the Bill
of Materials
8 / 34
Slab sensing thermostat
Step 2 Select the heating cable
Pentair Thermal Management offers the option of two self-regulating heating cables
with the ElectroMelt system. Cable selection is independent of application and
depends only upon supply voltage. ElectroMelt heating cables must only be powered
by single phase voltage. In applications where the power supply is three-phase, all
circuits must be wired to provide single-phase voltage to the heating cables. Select
the appropriate cable based on the supply voltage available for the application area.
Table 1 ElectroMelt Self-Regulating Heating Cable
Supply voltage
Catalog number
208 V, 240 V, 277 V
EM2-XR
347 V
EM3-XR
Example: Surface Snow Melting System
Supply voltage
277 V (from Step 1)
Heating cable
EM2-XR
Example: Anti-Icing System
Supply voltage
277 V (from Step 1)
Heating cable
EM2-XR
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Surface Snow Melting
and Anti-Icing
Step 3 Determine the required watt density
1. Determine design
conditions
3. Determine the
required watt density
4. Determine heating
cable spacing
5. Determine the total
area to be protected
6. Determine heating
cable length
8. Select the connection
kits and accessories
9. Select the control
system and
power distribution
10. Complete the Bill
of Materials
For maximum performance from any snow melting system, you must first take into
account the local snowfall and icing patterns. A system design that works well in one
city may be inadequate in another. The energy required to melt snow varies with air
temperature, wind speed, relative humidity, snow density, and the depth of the snow
on the pavement.
Table 2 summarizes the required watt density for most major cities in North
America based on typical minimum ambient temperatures and the snowfall and
icing patterns. Select the city from the list, or closest city, where similar climatic
conditions exist.
Table 2 Required Watt Density for Surface Snow Melting
Watts/ft2
City
Watts/m2
Concrete
Pavers
Concrete
Pavers
35
35
40
35
35
35
35
35
50
35
35
50
35
45
35
35
35
35
40
40
45
40
40
40
40
40
50
35
40
50
40
50
40
35
35
40
377
377
431
377
377
377
377
377
538
377
377
538
377
484
377
377
377
377
431
431
484
431
431
431
431
431
538
377
431
538
431
538
431
377
377
431
Calgary, AB
45
45
484
484
Edmonton, AB
Fredericton, NB
Halifax, NS
Moncton, NB
Montreal, QC
Ottawa, ON
Prince George, BC
Quebec, QC
Regina, SK
Saskatoon, SK
St. John, NB
St. John’s, NF
Sudbury, ON
Thunder Bay, ON
Toronto, ON
Vancouver, BC
Winnipeg, MB
50
40
35
40
45
45
50
45
50
50
40
35
40
50
35
35
50
50
45
40
40
45
45
55
45
55
50
45
35
45
55
40
40
55
538
431
377
431
484
484
538
484
538
538
431
377
431
538
377
377
538
538
484
431
431
484
484
592
484
592
538
484
377
484
592
431
431
592
USA
Surface Snow
Melting – MI
Surface Snow
Melting – ElectroMelt
Baltimore, MD
Boston, MA
Buffalo, NY
Chicago, IL
Cincinnati, OH
Cleveland, OH
Denver, CO
Detroit, MI
Great Falls, MT
Greensboro, NC
Indianapolis, IN
Minneapolis, MN
New York, NY
Omaha, NE
Philadelphia, PA
Salt Lake City, UT
Seattle, WA
St. Louis, MO
Roof and Gutter
De-Icing
7. Determine the
electrical parameters
Surface Snow Melting
Fire Sprinkler System
Freeze Protection
2. Select the heating
cable
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
Canada
Floor Heating
To provide faster heat-up, the required watt density in Table 2 is greater than what is
suggested by ASHRAE.
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
9 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Freezer Frost
Heave Prevention
Note:
Surface snow melting and anti-icing – electromelt
Example: Surface Snow Melting System
Geographical location Buffalo, NY (from Step 1)
Required watt density 40 W/ft2 (431 W/m2) (from Table 2)
ANTI-ICING
From the minimum ambient temperature and average wind speed that you
determined in Step 1 for your anti-icing application, use the tables below to
determine the required watt density for that application.
Table 3 Required Watt Density for Ice-Free Surfaces W/ft2
Minimum ambient
temperature
°F
Average wind speed during freezing periods
5 mph
10 mph
15 mph
20 mph
20°F
30
30
35
40
10°F
30
30
35
45
0°F
30
40
45
60
–10°F
30
45
60
80
–20°F
35
55
80
–
–30°F
40
65
–
–
–40°F
45
75
–
–
Table 4 Required Watt Density for Ice-Free Surfaces W/m2
Minimum ambient
temperature
°C
Average wind speed during freezing periods
8 kmph
16 kmph
24 kmph
32 kmph
–7°C
323
323
377
431
–12°C
323
323
377
484
–18°C
323
431
484
646
–23°C
323
484
646
861
–29°C
377
592
861
–
–34°C
431
699
–
–
–40°C
484
807
–
–
Note: This procedure is derived from finite model studies of 4-inch slabs and is
applicable to standard concrete pavement from 4 to 6 inches thick placed directly on
grade. If your application involves other materials or construction, contact your
Pentair Thermal Management representative.
Example: Anti-Icing System
Minimum ambient temperature 10°F (–12°C) (from Step 1)
10 / 34
Average wind speed
20 mph (32 kmph) (from Step 1)
Required watt density
45 W/ft2 (484 W/m2) (from Table 3 and Table 4)
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Surface Snow Melting
and Anti-Icing
Step 4 Determine heating cable spacing
1. Determine design
conditions
3. Determine the
required watt density
4. Determine heating
cable spacing
5. Determine the total
area to be protected
6. Determine heating
cable length
To determine your heating cable spacing, you need to know your applications’s power
output and required watt density.
The power output from the ElectroMelt heating cable depends on the cable type and
the supply voltage used in the application. Table 5 lists power output per linear foot
of heating cable determined by the supply voltage. Divide this figure by the required
watt density that you determined in Step 3. You will get the required heating cable
spacing in feet or meters as applicable. Multiply this figure by 12 inches or by 100
centimeters to determine your heating cable spacing.
Table 5 Heating Cable Spacing in Concrete
Supply voltage
Catalog number
Power output W/ft (W/m)
208 V
EM2-XR
30(98)
9. Select the control
system and power
distribution
240 V
EM2-XR
32(105)
277 V
EM2-XR
34(112)
10. Complete the Bill
of Materials
347 V
EM3-XR
24 (79)
8. Select the connection
kits and accessories
Heating cable spacing (in) =
(W/ft power output of cable per Table 5) x 12 in
W/ft2 requirement from Step 3
Heating cable spacing (cm) =
Surface Snow
Melting – MI
To determine cable spacing required for surface snow melting and anti-icing
Roof and Gutter
De-Icing
7. Determine the
electrical parameters
Surfaces
Fire Sprinkler System
Freeze Protection
2. Select the heating
cable
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
(W/m power output of cable per Table 5) x 100 cm
W/m2 requirement from Step 3
Surface Snow
Melting – ElectroMelt
Round answer to nearest whole number of inches or centimeters.
Example: Surface Snow Melting System
277 V (from Step 1)
Heating cable
EM2-XR (from Step 2)
Power output
34 W/ft (112 W/m2) (from Table 5)
Spacing
(34 W/ft x 12 in) /40 W/ft2 = 10.2 in
Rounded to 10 in
(112 W/m x 100 cm) / 431 W/m2 = 26 cm
Freezer Frost
Heave Prevention
Supply voltage
Example: Anti-Icing System
277 V (from Step 1)
Heating cable
EM2-XR (from Step 2)
Power output
34 W/ft (from Table 5)
Spacing
(34 W/ft x 12 in) / 45 W/ft2 = 9.1 in
Rounded to 9 in
(112 W/m x 100 cm) / 484 w/m2 = 23.1 cm
Rounded to 23 cm
11/13
11 / 34
Technical Data
Sheets
EN-RaychemElectroMeltSnowMelting-DG-H53393
Floor Heating
THERMAL MANAGEMENT SOLUTIONS
Supply voltage
Surface snow melting and anti-icing – electromelt
Stairs
Heat loss in stairs occurs from the two exposed surfaces: the top of the stair and
its side. Watt density requirements are therefore greater for snow melting and antiicing. Rather than calculating heating cable spacing in the stair, refer to Table 6 and
determine the number of runs of heating cable per stair based on the depth of the
stair. Space the heating cable evenly across the depth of the stair with one run 2 in
(5 cm) from the front, or nose, of the stair. This method will provide sufficient watt
density for both snow melting and anti‑icing.
Table 6 Heating cable runs per stair
Stair depth
Number of cable runs per stair
Less than 10.5 in (27 cm)
2
10.5–12 in (27–30 cm)
3
For landings in the stairway, use cable spacing as calculated for surfaces. As with
stairs, a run of heating cable must be placed 2 in (5 cm) from the exposed edge of
the landing leading to the stairs.
Anticipate and design for the addition of railings or other follow on construction that
will require cutting or drilling into the concrete as damage to installed heating cable
may occur. Allow for at least 4 inches clearance between the heating cable and any
planned cuts or holes.
Example: Surface Snow Melting and Anti-Icing System
Depth of stair
12 in (30 cm) (from Step 1)
Number of cable runs per stair
3 runs
Spacing
Equally spaced across the width of the stair with
one run 2 in (5 cm) from the front edge
Junction
box
5 ft
ir
Sta th
p
de in
12 cm)
(30
Ri
heser
igh
t (156 in
cm
Wid
th
(1.5
m)
pth
de
ing
d
n
La 3 ft )
9m
(0.
)
Fig. 5 Typical heating cable layout for concrete stairs
12 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Surface Snow Melting
and Anti-Icing
Step 5 Determine the total area to be protected
1. Determine design
conditions
Surfaces
4. Determine heating
cable spacing
Example: Surface Snow Melting System
5. Determine the total
area to be protected
Total area of concrete slab
6. Determine heating
cable length
8. Select the connection
kits and accessories
9. Select the control
system and
power distribution
10. Complete the Bill
of Materials
Example: Anti-Icing System
Total area of concrete slab
80 ft x 50 ft = 4000 ft2
(24.4 m x 15.2 m = 370.8 rounded to = 371 m2)
Wheel Tracks
To reduce power consumption for concrete driveways, it may be sufficient to provide
snow melting for only the wheel tracks.
Cable in 6 in minimum
(15 cm) from edge
unless curbs used
6'6" (2
Surface Snow
Melting – MI
Design wheel track applications with the same spacing used for concrete slabs.
Heating cable should run to the edge of each side of the wheel track and be laid in a
serpentine pattern along the length of the wheel track.
Roof and Gutter
De-Icing
7. Determine the
electrical parameters
80 ft x 50 ft = 4000 ft2
(24.4 m x 15.2 m = 370.8 rounded to = 371 m2)
Fire Sprinkler System
Freeze Protection
3. Determine the
required watt density
To determine the total amount of heating cable, you need to determine the surface
area you will be protecting from snow and ice accumulation. If assistance is required
in designing for irregular shaped areas, please contact your Pentair Thermal
Management representative.
2. Select the heating
cable
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
m) ty
p.
Surface Snow
Melting – ElectroMelt
Structurally sound welldrained base designed to
handle expected load and
environmental conditions
Freezer Frost
Heave Prevention
Fig. 6 Wheel track example
Stairs
Surface area of the stairs is not required to determine heating cable required.
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
13 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Surface Snow Melting
and Anti-Icing
1. Determine design
conditions
2. Select the heating
cable
3. Determine the
required watt density
4. Determine heating
cable spacing
Step 6 Determine heating cable length
SURFACES
Calculate the heating cable length by dividing the total heated area by the heating
cable spacing calculated in the previous steps. In Step 8, you will need to add
additional heating cable for connection kits and end terminations which will then
give you the total heating cable length.
Calculate the heating cable length for the surface as follows:
Heating cable length =
5. Determine the total
area to be protected
Heating cable spacing (in)
6. Determine heating
cable length
Heated area (m2) x 100
7. Determine the
electrical parameters
8. Select the connection
kits and accessories
9. Select the control
system and power
distribution
10. Complete the Bill
of Materials
Heated area (ft2) x 12
Heating cable spacing (cm)
Example: Surface Snow Melting System for Concrete Slab
Total area of concrete slab
4000 ft2 (371 m2) (from Step 5)
Cable spacing
10 in (26 cm) (from Step 4)
(4000 ft2 x 12 in) / 10 in spacing = 4800 ft
(371 m2 x 100 cm) / 26 cm spacing = 1427 m
Heating cable length
4800 ft (1427 m)
Example: Anti-Icing System for Concrete Slab
14 / 34
Total area of concrete slab
4000 ft2 (371 m2) (from Step 5)
Cable spacing
9 in (23 cm) (from Step 4)
(4000 ft2 x 12 in) / 9 in spacing = 5333 ft
(371 m2 x 100 cm) / 23 cm spacing = 1613 m
Heating cable length
5333 ft (1613 m)
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Stairs
Fire Sprinkler System
Freeze Protection
Junction
box
Ri
5 ft
th
ep
r d in
i
a
St 12 m)
c
(30
rh
Wid
th
(1.5
m)
eig
ht
(156 in
cm
Roof and Gutter
De-Icing
se
pth
de
ing t
d
n 3f )
La
9m
(0.
)
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
Surface Snow
Melting – MI
Fig. 7 Concrete stair example
Length of cable = No. of stairs x [(No. runs per stair x width of stair) + (2 x riser height)]
for stair (ft) (m)
Surface Snow
Melting – ElectroMelt
Use the formula below to determine the length of cable required for stairs. Stair area
is not needed for the cable length calculation. Two or three runs of heating cable will
be installed per stair as determined in Step 3. For landing areas, use the equation for
surfaces.
Example: Surface Snow Melting and Anti-Icing System for Stairs
10 stairs (from Step 1)
Number of cable runs per stair
3 runs
Width of stair
5 ft (1.5 m) (from Step 1)
Riser height
6 in (15 cm) convert to 0.5 ft (0.15 m) (from Step 1)
10 stairs x [(3 x 5 ft) + (2 x 0.5 ft)] = 160 ft
10 stairs x [(3 x 1.5 m) + (2 x 0.15 m)] = 48 m
Heating cable length
160 ft (48 m)
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
15 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Floor Heating
For applications where the landing area is very large or where an expansion joint
exists between the stairs and landing, consider the stairs and landing as two
separate areas. In these cases, determine the length of cable required for the stairs
as shown earlier in this section and select the cable for the landing as shown for
ramps, slabs, driveways, sidewalks, platform scales.
Freezer Frost
Heave Prevention
Number of stairs
Surface snow melting and anti-icing – electromelt
Surface Snow Melting
and Anti-Icing
1. Determine design
conditions
2. Select the heating
cable
3. Determine the
required watt density
4. Determine heating
cable spacing
5. Determine the total
area to be protected
6. Determine heating
cable length
7. Determine the
electrical parameters
8. Select the connection
kits and accessories
9. Select the control
system and
power distribution
10. Complete the Bill
of Materials
Step 7 Determine the electrical parameters
This section will help you determine the electrical parameters for an ElectroMelt
system including circuit breaker sizing and maximum circuit length. Total required
heating cable length divided by maximum circuit length will determine the number of
circuits required for your snow melting solution.
DETERMINE MAXIMUM CIRCUIT LENGTH
To determine maximum circuit length, it is important to establish a minimum startup
temperature for the system. The following tables provide maximum circuit lengths
based on minimum startup temperature, circuit breaker rating, and supply voltage.
Colder temperature startup requires shorter maximum circuit lengths. The use of an
automatic system, which energizes the system above 20°F (–7°C), ensures that you
can use maximum circuit lengths. Manual control systems may require you to use
shorter circuit lengths to compensate for startup below 20°F (–7°C).
A 30-mA ground-fault protection device (GFPD) must be used to provide protection
from arcing or fire, and to comply with warranty requirements, agency certifications,
and national electrical codes. If the heating cable is improperly installed, or
physically damaged, sustained arcing or fire could result. If arcing does occur, the
fault current may be too low to trip conventional circuit breakers.
Table 7 Maximum Circuit Length for Startup at 20°F (–7°C) in Feet
(Meters) using an Automatic Snow Control System
Heating cable supply voltage
Circuit Breaker
(A)
208 V
240 V
277 V
347 V
15
80 (24)
85 (26)
100 (31)
120
(37)
20
105 115 (35)
130 (40)
165 (50)
(76)
(32)
30
160 (49)
170 (52)
195 (59)
250 40
210 (64)
230 (70)
260 (79)
330 (101)
50
265 (81)
285 (87)
325 (99)
†
Table 8 Maximum Circuit Length for Startup at 0°F (–18°C) in Feet
(Meters) using a Manual Control System
Heating cable supply voltage
Circuit Breaker
(A)
15
208 V
75 (23)
240 V
80 (24)
277 V
90 (27)
347 V
107 (33)
20
100 (31)
110 (34)
120 (37)
148 (45)
30
145 (44)
160 (49)
180 (55)
225 (69)
288 (88)
40
200 (61)
210 (64)
240 (73)
50
245 (75)
265 (81)
300 (91)
†
† Not permitted
WARNING: To minimize the danger of fire from sustained electrical arcing if
the heating cable is damaged or improperly installed, and to comply with the
requirements of Pentair Thermal Management, agency certifications, and national
electrical codes, ground-fault equipment protection must be used on each heating
cable branch circuit. Arcing may not be stopped by conventional circuit protection.
Example: Surface Snow Melting and Anti-Icing System with Automatic Snow
Control
16 / 34
Startup temperature
20°F (–7°C) (from Step 1)
Circuit breakers
50 A
Supply voltage
277 V (from Step 1)
Maximum circuit length
325 ft (99 m) (from Table 7)
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Determine number of circuits
Use the following formula to determine number of circuits for the system:
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
Number of circuits = Heating cable length required
Fire Sprinkler System
Freeze Protection
Maximum heating cable circuit length
Example: Surface Snow Melting
Surfaces
Total heating cable length
4800 ft (1427 m) (from Step 6)
Maximum circuit length
325 ft (99 m) (from above)
Number of circuits
4800 / 325 = 14.8 rounded to 15 circuits
Stairs
160 ft (48 m) (from Step 6)
Maximum circuit length
325 ft (99 m) (from above)
Number of circuits
160 / 325 = 0.5 rounded to 1 circuit
Roof and Gutter
De-Icing
Total heating cable length
Example: Anti-Icing System
Surfaces
5333 ft (1613 m) (from Step 6)
Maximum circuit length
325 ft (99 m)
Number of circuits
5333 / 325 = 16.4 rounded to 17 circuits
Surface Snow
Melting – MI
Total heating cable length
Stairs
Total heating cable length
160 ft (48m) (from Step 6)
Maximum circuit length
325 ft (99 m) (from above)
Number of circuits
160 / 325 = 0.5 rounded to 1 circuit
Determine Transformer load
Surface Snow
Melting – ElectroMelt
The total transformer load is the sum of load on all the circuit breakers in the
system.
Calculate the Circuit Breaker Load (CBL) as:
CBL (kW) =
Circuit breaker rating (A) x 0.8 x Supply voltage
1000
If the CBL is equal on all circuit breakers, calculate the Total Transformer Load as:
Total Transformer Load (kW) = CBL x Number of circuits
If the CBL is not equal on all circuit breakers, calculate the Total Transformer Load as:
Freezer Frost
Heave Prevention
Calculate the Total Transformer Load as follows:
Total Transformer Load (kW) = CBL1 + CBL2 + CBL3...+ CBLN
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
17 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Example: Surface Snow Melting
Circuit breaker load
(50 A x 0.8 x 277 V) / 1000 = 11.1 kW
Transformer Load
11.1 kW x 16 circuits = 177.6 kW rounded to 178 kW
178 kW
Example: Anti-Icing System
Surface Snow Melting
and Anti-Icing
1. Determine design
conditions
2. Select the heating
cable
3. Determine the
required watt density
4. Determine heating
cable spacing
5. Determine the total
area to be protected
6. Determine heating
cable length
7. Determine the
electrical parameters
8. Select the connection
kits and accessories
9. Select the control
system and
power distribution
Circuit breaker load
(50 A x 0.8 x 277 V) / 1000 = 11.1 kW
Transformer load
11.1 kW x 18 circuits = 199.8 kW rounded to 200 kW
200 kW
Step 8 Select the connection kits and accessories
Pentair Thermal Management provides all the connection kits and accessories
necessary to satisfy code, approval agency, and warranty requirements for the
ElectroMelt system. Additional heating cable will be required for connection kits
and end terminations. Adding the additional heating cable allowances needed with
the heating cable length required for the layout will give you the total heating cable
length required.
Prepare a drawing of your system showing distinct circuits, layout of cables,
connection kits, expansion joints, drains, heated pathways for meltwater, power
connections, junction boxes, and sensors. Determine length of cable from slab for
power connection for all circuits. If possible, avoid crossing expansion, crack control,
or other pavement joints. Use the EMK‑XEJ expansion joint kit to protect the heating
cable if crossing is unavoidable.
Junction boxes must be mounted above grade to prevent water entry. Use an EMKXJB or equivalent UL Listed or CSA Certified weatherproof junction box. Protect
heating cable from slab to junction box inside individual 1-inch rigid metal conduits.
Do not penetrate floors or walls with conduit, nor insulate the conduit.
10. Complete the Bill
of Materials
18 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Table 9 Connection Kits and Accessories
Catalog
number
Description
Standard
packaging Usage
Heating cable
allowance 1
EMK-XP
Power connection and
end seal kit
1
1 per circuit
3 ft (1 m) for connection
plus conduit length for
power connection and
conduit length for end
seal
EMK-XS
Splice kit
1
As required
1 ft (30 cm)
EMK-XJR
Jacket repair kit
1
EMK-CT
Nylon cable ties
100/pack
EMK-XT
Crimping tool
1
SMCS
Snow melt caution sign
1
Dimensions: 6 x 4 in (150 x 100 mm)
1 minimum
per system
EMK-XEJ
Expansion joint kit
1 per expansion
joint crossing
EMK-XJB
1
Junction box
Dimensions: 15 1/2 x 11 3/4 x 7 5/8 in
(394 x 299 x 194 mm)
Power connection EMK-XP
End seal EMK-XP
Fire Sprinkler System
Freeze Protection
Connection Kits
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
Roof and Gutter
De-Icing
Accessories
1 per foot of cable
used
–
–
Surface Snow
Melting – MI
–
–
Surface Snow
Melting – ElectroMelt
1
As required
–
1 1/2 ft (45 cm)
Freezer Frost
Heave Prevention
1–2 ft (30–60 cm) for
each end in the junction
box
Maximum of two
circuits per EMK-XJB
Floor Heating
FH-2616A-1 Propane torch is suitable for heat
shrinking the connection kits;
includes a hose, a handle assembly,
and comes equipped with a regulating valve.
Shipping weight: 5 lbs (2.27 kg)
THERMAL MANAGEMENT SOLUTIONS
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
19 / 34
Technical Data
Sheets
1 Allow extra heating cable for ease of component installation.
Surface snow melting and anti-icing – electromelt
Example: Surface Snow Melting System
Number of circuits
15 for concrete slab + 1 for stairs = 16
Power connection kits
16 power connection kits
Conduit length (from slab to junction box)
Power connection
15 ft (4.5 m)
End seal
15 ft (4.5 m)
(15 ft + 15 ft) x 16 circuits = 480 ft
(4.5 m + 4.5 m) x 16 circuits = 144 m
Heating cable allowance for each power connection
3 ft x 16 circuits = 48 ft
1 m x 16 circuits = 16 m
Total heating cable length required
528 ft (160 m)
Example: Anti-Icing System
Number of circuits
17 for concrete slab + 1 for stairs = 18
Power connection kits
18 power connection kits
Conduit length (from slab to junction box)
Power connection
15 ft (4.5 m)
End seal
15 ft (4.5 m)
(15 ft + 15 ft) x 18 circuits = 540 ft
(4.5 m + 4.5 m) x 18 circuits = 162 m
Heating cable allowance for each power connection
3 ft x 18 circuits = 54 ft
20 / 34
1 m x 18 circuits = 18 m
Total heating cable length required
594 ft (180 m)
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Surface Snow Melting
and Anti-Icing
Step 9 Select the control system and power distribution
1. Determine design
conditions
3. Determine the
required watt density
4. Determine heating
cable spacing
5. Determine the total
area to be protected
6. Determine heating
cable length
8. Select the connection
kits and accessories
9. Select the control
system and
power distribution
10. Complete the Bill
of Materials
Select a control system from the following three options, but keep in mind that
an automatic snow controller offers the highest system efficiency and the lowest
operating cost.
• Manual on/off control
• Slab sensing thermostat
• Automatic snow melting controller
If the current rating of the control means is exceeded, all three methods will require
contactors sized to carry the load. Each method offers a tradeoff balancing initial
cost versus energy efficiency and ability to provide effective snow melting. If the
system is not energized when required, snow will accumulate. If the system is
energized when it is not needed, there will be unnecessary power consumption.
Choose the control method that best meets the project performance requirements.
For additional information, refer to the “Typical Control Diagrams,” Table 7, or contact
your Pentair Thermal Management representative for details.
Roof and Gutter
De-Icing
7. Determine the
electrical parameters
Control Systems
Fire Sprinkler System
Freeze Protection
2. Select the heating
cable
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
Manual On/Off Control
Slab Sensing Thermostat
Automatic Snow Melting Controller
For areas where a large number of circuits are required, the DigiTrace ACS-30 can
be used. The Surface Snow Melting control mode in the ACS-30 includes an External
Device control option. This option allows a Snow/Moisture sensing controller (from
Table 10) to be integrated into the ACS-30 system. Note that sensors (snow or
gutter) cannot be directly connected to the ACS-30 system. Refer to the ACS-30
Programming Guide (H58692) for more information on system setup.
Freezer Frost
Heave Prevention
With an automatic snow controller, the snow melting system is automatically
energized when both precipitation and low temperature are detected. When
precipitation stops or the ambient temperature rises above freezing, the system
is de-energized. In addition, a slab sensor de-energizes the system after the slab
reaches the slab sensing set point even if freezing precipitation is still present. Using
an automatic snow controller with a slab sensor offers the most energy-efficient
control solution.
Surface Snow
Melting – ElectroMelt
A slab sensing thermostat can be used to energize the system whenever the slab
temperature is below freezing, but is not energy efficient when used as the sole
means of control. The slab sensing thermostat is recommended for all snow melting
applications, even when an automatic snow controller is used, and is required for
all asphalt and paver installations (for asphalt, it prevents surface damage due to
overheating).
Surface Snow
Melting – MI
A manually controlled system is operated by a switch that controls the system power
contactor. This method requires constant supervision to work effectively. A manual
system can be controlled by a building management system.
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
21 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Optional
RCU-3 or RCU-4
remote control unit
CIT-1
snow sensor
To additional
SC-40C satellite
contactors
Optional
SC-40C
satellite
contactor
SIT-6E pavement
mounted sensor
To power supply
To heating cable(s)
APS-4C (shown) with SC-40C satelllite
contactor or APS-3C snow controller
Environmental Technology, Inc, (ETI) of
South Bend, Indiana offers a complete
line of automatic controllers for snow
melting applications.
To power supply or incorporate the ETI snow
melting control system into a power
distribution panel
To heating cable(s)
Fig. 8 Automatic snow melting control system
Table 10 Control Systems Catalog number
Description
Slab Sensing Thermostat
ECW-GF
Electronic ambient sensing controller with 30-mA ground-fault protection. The controller can be programmed to maintain temperatures up to 200°F (93°C) at voltages from
100 to 277 V and can switch current up to 30 Amperes. The ECW-GF is complete with
a 25-ft (7.6-m) temperature sensor and is housed in a Type 4X rated enclosure. The
controller features an AC/DC dry alarm contact relay.
An optional ground-fault display panel (ECW-GF-DP) that can be added to provide
ground-fault or alarm indication in applications where the controller is mounted in
inaccessible locations.
ECW-GF-DP
HE
AT
ER
CY
CL
An optional remote display panel (ECW-GF-DP) can be added to provide ground-fault
or alarm indication in applications where the controller is mounted in inaccessible
locations.
ETI PD Pro
Automatic snow and ice melting controller for pavement, sidewalks, loading docks,
roofs, gutters and downspouts in commercial and residential environments.
The PD Pro interfaces with up to two sensors, (any combination of CIT-1, GIT-1 or SIT6E) to meet site requirements. The PD Pro is housed in an environmentally-sheltered
Type 4X enclosure and weighs only 3 pounds.
ETI GF Pro
Automatic snow and ice melting controller for pavement, sidewalks, loading docks,
roofs, gutters and downspouts in commercial and residential environments.
The GF Pro interfaces with up to two sensors, (any combination of CIT-1, GIT-1 or SIT6E) to meet site requirements. The GF Pro is housed in an environmentally-sheltered
Type 4X enclosure and weighs only 3 pounds.
E
Features a built-in 30 mA, self-testing Ground-Fault Equipment Protection (GFEP)
capability, digitally filtered to minimize false tripping. A ground-fault alarm must be
manually reset using the Test/Reset switch before heater operation can continue.
22 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Table 10 Control Systems Catalog number
Description
Automatic Snow Melting Controllers
Automatic snow melting controller housed in a Type 3R enclosure provides effective,
economical automatic control of all snow melting applications. Features include:
120 V or 208–240 V models, 24-A DPDT output relay and an adjustable hold-on timer.
Enclosure dimensions: 11-1/2 in x 9-1/8 in x 6-9/16 in (292 mm x 232 mm x 167 mm)
APS-4C
Enclosure dimensions: 11-1/2 in x 9-1/8 in x 6-9/16 in (292 mm x 232 mm x 167 mm)
SC-40C
Enclosure dimensions: 11-1/2 in x 9-1/8 in x 6 in (292 mm x 232 mm x 152 mm)
Surface Snow
Melting – MI
Satellite contactor power control peripheral for an APS-4C snow melting controller, housed in a Type 3R enclosure. Features include: 277 V single-phase or 208–240,
277/480 and 600 V three-phase models, built-in 3-pole contactor and integral 30 mA
ground-fault circuit interrupter.
Roof and Gutter
De-Icing
Automatic snow melting controller housed in a Type 3R enclosure provides effective,
economical automatic control of all snow melting applications. The APS-4C can operate with any number of SC-40C satellite contactors for larger loads. Features include:
277 V single-phase or 208–240, 277/480, and 600 V three-phase models, built-in
3-pole contactor, integral 30 mA ground-fault circuit interrupter and an adjustable
hold-on timer.
Fire Sprinkler System
Freeze Protection
APS-3C
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
Snow Melting and Gutter De-Icing Sensors and Accessories
SIT-6E
Pavement-mounted sensor signals for the heating cable to turn on when the
pavement temperature falls below 38°F (3.3°C) and precipitation in any form is
present. Microcontroller technology effectively eliminates ice bridging while ensuring
accurate temperature measurement. For use with either an APS-3C or APS-4C
automatic snow melting controller.
RCU-3
The RCU–3 provides control and status display to the APS–3C controller from a
remote location. It has a 2, 4, 6 or 8 hour CYCLE TIME adjustment, independent of
APS-3C setting.
RCU-4
The RCU–4 provides control and status display to the APS–4C controller and SC-40C
Satellite Contactor from a remote location. It has a 2, 4, 6 or 8 hour CYCLE TIME
adjustment, independent of the APS-4C or SC-40C setting.
Freezer Frost
Heave Prevention
Overhead snow sensor that detects precipitation or blowing snow at ambient temperatures below 38°F (3.3°C). For use with either an APS-3C or APS-4C automatic snow
melting controller.
Surface Snow
Melting – ElectroMelt
CIT-1
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
23 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Table 10 Control Systems Catalog number
Description
Electronic Controllers
A0
A1
A2
A3
A4
A5
A6
A7
ACS-UIT2
ACS-PCM2-5
The DigiTrace ACS-30 Advanced Commercial Control System is a multipoint
electronic control and monitoring system for heat-tracing used in various commercial
applications such as pipe freeze protection, roof and gutter de-icing, surface snow
melting, hot water temperature maintenance and floor heating. The DigiTrace ACS-30
system can control up to 260 circuits with multiple networked ACS-PCM2-5 panels,
with a single ACS-UIT2 user interface terminal. The ACS-PCM2-5 panel can directly
control up to 5 individual heat-tracing circuits using electromechanical relays rated at
30 A up to 277 V.
ProtoNode-LER
ProtoNode-RER
The DigiTrace ProtoNode is an external, high performance multi-protocol gateway for
customers needing protocol translation between Building Management Systems (BMS)
and the DigiTrace ACS-30 or C910-485 controllers.
PROTOCESSOR
SERIAL ETHERNET
PROTONODE
B0
B1
B2
B3
S0
S1
S2
S3
By FieldServer Technologies
www.ProtoCessor.com
RS 485 GND
RS 485 RS 485+
The ProtoNode-LER is for LonWorks® systems; and the ProtoNode-RER is for
BACnet® or Metasys® N2 systems.
+PWR
- PWR
FRAME GND
RTD10CS
RTD-200
RTD50CS
Stainless steel jacketed three-wire RTD (Resistance Temperature Detector) used with
DigiTrace C910-485 and ACS-30 controllers.
RTD10CS: 10-ft (3 m) flexible armor, with 18-in (457 mm) lead wire and 1/2-inch NPT
bushing.
RTD-200: 6-ft (1.8 m) fluoropolymer with 1/2-in NPT bushing.
RTD50CS: 50-ft (3 m) flexible armor with 1/2-in NPT bushing
Power Distribution
Single Circuit Control
Heating cable circuits that do not exceed the current rating of the selected
temperature control can be switched directly (see Fig. 9).
Group Control
If the current draw exceeds the switch rating, or if the controller will activate more
than one circuit, or group control, an external contactor must be used (see Fig. 9).
Large systems with many circuits should use an SMPG power distribution panel.
The SMPG is a dedicated power-distribution, control, ground-fault protection,
monitoring, and alarm panel for surface snow melting and anti-icing applications.
This enclosure contains an assembled circuit-breaker panelboard. Panels are
equipped with ground-fault circuit breakers with or without alarm contacts. The
group control package allows the system to operate automatically in conjunction
with an ambient-sensing thermostat, individual electronic, or duty cycle controller.
24 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Single circuit control
Group control
Temperature
controller
1 ø supply
N
Temperature
controller
ø
1-pole
GFEP breaker
1
1-pole
GFEP breaker
C
ø supply
N
ø
ø
ø
1
G
2
Heating cable
sheath, braid
or ground
3-phase 4-wire
supply (WYE)
Fire Sprinkler System
Freeze Protection
ø
Heating
cable
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
3
Roof and Gutter
De-Icing
Contactor
3-pole main
breaker
N
G (Typ 3)
Heating cable
sheath, braid
or ground
Fig. 9 Single circuit and group control
Surface Snow
Melting – MI
Mounting brackets
Nameplate
NP
Snow/Ice
melt controller
Heater thermostat
(3R only)
Power on light
HTC energized light
NP
NP
G
G
NP
NP
EUR - 5A
NP
Ground bar
Main breaker
(optional)
Panel
board
Branch
breakers
(2 pole)
C.B. tripped alarm
Heater cycle
atimed control
R
Heat trace
contactor
Control wiring
NP
Panelboard
lugs
Heater (3R only)
NP
Exterior View
Interior View
Main circuit breaker (optional)
N
Incoming
power
Remote annunciation alarm
(circuit breaker
with alarm type #3)
Slab
temperature sensor
Control transformer
GIT-1
EUR-5A SNOW SWITCH
24 V
4
AUTOMATIC SNOW/ICE MELTING CONTROL PANEL
6
2
SUPPLY
SNOW/ICE
8
HOURS
60°F
55°F
HEATER
Aerial
CIT-1 snow sensor
10
0
HEATER
CYCLE
50°F
45°F
65°F
Gutter
ice sensor
70°F
75°F
80°F
85°F
TEMPERATURE
SIT-6E
One-pole with 30-mA
ground-fault trip (277 V)
Pavement-mounted
sensor
Floor Heating
Three-pole main contactor
Fuse
Freezer Frost
Heave Prevention
Fig. 10 SMPG1 power distribution panel
Surface Snow
Melting – ElectroMelt
Door lock handle
Single Ø
connection
GND
Braid
Fig. 11 Typical wiring diagram of group control with SMPG1
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
25 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Table 11 Power Distribution
Catalog number
Description
Power Distribution and Control Panels
SMPG1
Single-phase power distribution panel that includes ground-fault protection, monitoring, and control for snow melting systems. Single-phase voltages include 208 and 277 V.
If standard configurations do not meet your needs, custom SMPG panels are available
and processed under the catalog number SMPG-GENERAL, part number P000000763.
Please contact your Pentair Thermal Management representative for a custom SMPG
panel quotation.
NP
NP
NP
NP
NP
NP
NP
Contactors
E104
Three-pole, 100 A per pole, 600 V maximum contactor housed in UL Listed, CSA Certified, NEMA 4X enclosure with two 1-inch conduit entries. When ordering, select coil
voltage (110–120, 208–240, 277 V).
Enclosure dimensions: 13-1/2 in x 9-1/5 in x 6-11/16 in (343 mm x 234 mm x 170 mm).
E304
Three-pole, 40 A per pole, 600 V maximum contactor housed in UL Listed, CSA Certified
NEMA 4X enclosure with two 1-inch conduit entries. When ordering, select coil voltage
(110–120, 208–240, 277 V).
Enclosure dimensions: 9-1/2 in x 7-1/5 in x 6-11/16 in (241 mm x 183 mm x 170 mm).
Example: Surface Snow Melting System
This system has 16 circuits and will require a specially designed control panel.
As many as eight SIT-6E sensors can be used in this configuration. The amount
depends upon designer preference.
Example: Anti-Icing System
This system has 18 circuits and will require a specially designed control panel.
As many as eight SIT-6E sensors can be used in this configuration. The amount
depends upon designer preference.
26 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Surface Snow Melting
& Anti-Icing
Step 10 Complete the Bill of Materials
1. Determine design
conditions
Fire Sprinkler System
Freeze Protection
2. Select the heating
cable
If you used the Design Worksheet to document all your design parameters, you
should have all the details you need to complete the Bill of Materials.
Pipe Freeze Protection
and Flow Maintenance
Surface Snow Melting and Anti-Icing Design
3. Determine the
required watt density
4. Determine heating
cable spacing
5. Determine the total
area to be protected
6. Determine heating
cable length
Roof and Gutter
De-Icing
7. Determine the
electrical parameters
8. Select the connection
kits and accessories
9. Select the control
system and
power distribution
10. Complete the Bill
of Materials
Surface Snow
Melting – MI
Surface Snow
Melting – ElectroMelt
Freezer Frost
Heave Prevention
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
27 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
ElectroMelt System Surface Snow Melting and Anti-Icing Design Worksheet
Step  Determine design conditions
Size and layout
Supply
voltage
Phase
Control method
❑ Surface snow melting
Geographical location:
_____________________
Slab surface (ft/m)___________________
❑ 208 V
❑ Single-phase
❑ Manual on/off control
Ramp surface (ft/m)__________________
❑ 240 V
❑ Slab-sensing thermostat
❑ Anti-icing
Minimum ambient temperature:
_____________________
Average wind speed during
freezing periods (mph/kmph):
____________________
Stairs
❑ 277 V
❑ Automatic snow melting
controller
Application
Number of stairs
_______________
Width of stair (ft/m) _______________
Riser height (in/cm)_______________
Paving material
Depth of stair (in/cm)_______________
Landing dimensions
(ft/m)
_______________
❑ Concrete pavement
Wheel tracks
❑ 347 V
Track length (ft/m) _____________
❑ In concrete under paving stones Example:
9 Surface snow melting
Slab surface:
9 Buffalo, NY
Stairs
9 Concrete slab
Number of stairs 10
Width of stair
5 ft
Riser height
6 in
Depth of stair
12 in
80 ft x 50 ft
9 277 V
9 Single-phase 9 Automatic snow melting
controller
Step  Select the heating cable
See Table 1
❑ EM2-XR
❑ EM3-XR
Example:
9 EM2-XR
Step  Determine the required watt density
Surface snow melting
Anti-icing
See Table 2
See Table 3 and Table 4
Geographical location: _________________________ Minimum ambient temperature (°F/°C):
_______
Required watt density (W/ft2)(W/m2):___________________________ Average wind speed during freezing periods (mph/kmph): ______
Required watt density (W/ft2)(W/m2):
_______
Example:
Geographical location: Buffalo, NY
Required watt density: 40 W/ft2
28 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Step  Determine heating cable spacing
See Table 5
Pipe Freeze Protection
and Flow Maintenance
ElectroMelt System Surface Snow Melting and Anti-Icing Design Worksheet
Surfaces
Power output (W/ft)
x 12 in/ft ) /
=
Watt density (W/ft2)
Heating cable spacing (in)
Note: Round result to the nearest whole number of inches or centimeters.
Stairs
Calculate the heating cable needed for stairs and landing
Determine the number of cable runs needed:
Fire Sprinkler System
Freeze Protection
(
Depth of stair: <10.5 in (27 cm): 2 cable runs
Roof and Gutter
De-Icing
Depth of stair: 10.5–12 in (27–30 cm): 3 cable runs
Cable runs needed:
Concrete stair depth (in/cm):
Number of cable runs:
Spacing:
Example:
Surfaces
34 W/ft
Power output (W/ft)
40 W/ft2
x 12 in/ft ) /
=
Watt density (W/ft )
2
10 in
Heating cable spacing (in/cm)
Note: Round result to the nearest whole number of inches or centimeters.
Stairs
Calculate the heating cable needed for stairs and landing
Surface Snow
Melting – MI
(
Determine the number of cable runs needed:
Depth of stair: <10.5 in (27 cm): 2 cable runs
Depth of stair: 10.5–12 in (27–30 cm): 3 cable runs
3
Cable runs needed:
12 in
Number of cable runs:
3
Spacing:
Equally spaced across the width of the stair
with one run 2 in from the front edge
Step  Determine the total area to be protected
Surfaces
Length (ft/m)
x
=
Width (ft/m)
Surface area to be protected (ft2/m2)
Length
x
50 ft
=
Width
4000 ft2
Surface area to be protected (ft)
Freezer Frost
Heave Prevention
Example:
80 ft
Surface Snow
Melting – ElectroMelt
Concrete stair depth (in/cm):
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
29 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Step  Determine the heating cable length
Surfaces
Total concrete slab area (ft2/m2)
x 12 in /
=
Heating cable spacing (in/cm)
Heating cable length for surface (ft/m)
Calculate the heating cable for stairs and landing
No. of stairs
x
[(
No. of runs per stair
x
) + ( 2 x
)]=
Width of stair (ft/m)
Riser height (ft/m)
Heating cable length for stairs (ft/m)
Note: Additional heating cable for connection kits and end terminations is calculated in Step 8.
Calculate heating cable needed for wheel tracks
x 2 x 4 runs
=
Length (ft/m)
Wheel track to be protected (ft/m)
Total heating cable length required (ft/m)
Example:
Surfaces
4000 ft2
Total concrete slab area
x
12 in
/
10 in
Heating cable spacing
=
=
4800
Heating cable length for surface
Calculate the heating cable for stairs and landing
10
No. of stairs
x
[(
3
No. of runs per stair
x
5 ft
Width of stair
) + ( 2 x
0.5 ft
Riser height
)] =
160 ft
Heating cable length for stairs
Note: Additional heating cable for connection kits and end terminations is calculated in Step 8.
4960 ft
Total heating cable length required
30 / 34
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
THERMAL MANAGEMENT SOLUTIONS
Step  Determine the electrical parameters
See Table 7 and Table 8
Pipe Freeze Protection
and Flow Maintenance
ElectroMelt System Surface Snow Melting and Anti-Icing Design Worksheet
Determine number of circults
/
=
Maximum heating cable circuit length (ft/m)
Number of circuits
Determine total transformer load
Calculate circuit breaker load (CBL)
(
Circuit breaker rating (Amps )
x 0.8 x
Supply voltage
)
/ 1000
=
Circuit breaker load (kW)
Roof and Gutter
De-Icing
Calculate the total transformer load as follows:
If the CBL is equal on all circuits, calculate the transformer load as:
Circuit breaker load (kW)
x
Fire Sprinkler System
Freeze Protection
Heating cable length required for surface (ft/m)
=
Number of breakers
Total transformer load (kW)
=
CBL1 + CBL2 + CBL3... + CBLN
Total transformer load (kW)
Surface Snow
Melting – MI
If the CBL is NOT equal on all circuits, calculate the transformer load as:
Example:
Determine number of circults: Surfaces
4800 ft
325 ft
/
=
Maximum heating cable circuit length
14.8 rounded to 15
Number of circuits
Determine number of circults: Stair
160 ft
Heating cable length required for surface
325 ft
/
=
Maximum heating cable circuit length
0.5 rounded to 1
Number of circuits
(
50 A
Circuit breaker rating
11.1 kW
Circuit breaker load (kW)
x 0.8
x
x
277 V
Supply voltage
)
/ 1000
=
16
=
Number of breakers
11.1 kW
Circuit breaker load (kW)
177.6 kW rounded to 178
Total transformer load (kW)
Freezer Frost
Heave Prevention
Determine transformer load
Surface Snow
Melting – ElectroMelt
Heating cable length required for surface
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
31 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
Surface snow melting and anti-icing – electromelt
Step  Select the connection kit and accessories
See Table 9
Connection kits
Description
Heating cable
allowance
Quantity
T EMK-XP
Power connection and end seal kit
____________
__________________
T EMK-XS
Splice kit
____________
__________________
Accessories
Description
Quantity
T EMK-XJR
Jacket repair kit
____________
T EMK-CT
Nylon cable ties
____________
T EMK-XT
Crimping tool
____________
T SMCS
Snow melt caution sign
____________
T EMK-XEJ
Expansion joint kit
____________
__________________
T EMK-XJB
Junction box
____________
__________________
T FH-2616A-1
Propane torch
____________
Total heating cable
allowance for connection kits
+
=
Total+heating cable length + Total heating cable allowance
Total heating cable
= for connection kits
=
Number circuits for concrete slab Circuit(s) for stairs Circuit(s) for expansion joints Total no. of circuits Total no. of power
connection
kits
length
required
(
Power connection conduit length
(slab to junction box) (ft/m)
Cable allowance per
circuit connection (ft/m)
Total conduit length (ft/m)
Total heating cable length (ft/m)
)
+
End seal conduit length
(slab to junction box) (ft/m)
x
x
=
Total number of circuits
=
Total number of circuits
+
=
Total allowance per
power connection kit (ft/m)
+
=
Total heating cable allowance (ft/m)
Total conduit length (ft/m)
Total heating cable allowance
per power connection (ft/m)
Total additional
heating cable (ft/m)
Total heating cable with
connection kit allowance (ft/m)
Example:
15
1
16
16
+
=
+
=
Number circuits for concrete slab Circuit(s) for stairs Circuit(s) for expansion joints Total no. of circuits Total no. of power connection kits
(
15 ft
Power connection conduit length
(slab to junction box)
3 ft
Cable allowance per
circuit connection
480 ft
Total conduit length
630 ft
Total heating cable length
32 / 34
+
x
+
+
15 ft
)
End seal conduit length
(slab to junction box)
x
16
=
Total number of circuits
16
=
Total number of circuits
48 ft
=
Total allowance per
power connection kit
63
=
Total heating cable allowance
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
480 ft
Total conduit length
48 ft
Total heating cable allowance
per power connection
528 ft
Total additional heating cable
693 ft
Total heating cable with
connection kit allowance
THERMAL MANAGEMENT SOLUTIONS
Step  Select the control system and power distribution Control Systems
See Table 10.
T ECW-GF
Electronic thermostat with 25-ft sensor
____________
T ECW-GF-DP
Remote display panel for ECW-GF
____________
T ETI PD Pro
Automatic snow and ice melting controller
____________
T ETI GF-Pro
Automatic snow and ice melting controller
____________
T APS-3C
Automatic snow and ice melting controller
____________
T APS-4C
Automatic snow and ice melting controller
____________
T SC-40C
Satellite contactor
____________
T CIT-1
Overhead snow sensor
____________
T SIT-6E
Pavement-mounted sensor
____________
T RCU-3
Remote control unit for APS-3C
____________
T RCU-4
Remote control unit for APS-4C
____________
T ACS-UIT2
ACS-30 user interface terminal
____________
T ACS-PCM2-5
ACS-30 power control panel
____________
T ProtoNode-LER
Multi-protocol gateway
____________
T ProtoNode-RER
Multi-protocol gateway
____________
T RTD3CS
Resistance temperature device for DigiTrace ACS-30
____________
T RTD10CS
Resistance temperature device for DigiTrace ACS-30
____________
T RTD-200
Resistance temperature device for DigiTrace ACS-30
____________
T RTD50CS
Resistance temperature device for DigiTrace ACS-30
____________
Power distribution and
control panels
Description
Quantity
T SMPG1
Single-phase power distribution panel
____________
Contactors and junction boxes
Description
Quantity
T E104
Three-pole, 100 A per pole contactor
____________
T E304
Three-pole, 40 A per pole contactor
____________
Surface Snow
Melting – MI
Quantity
Roof and Gutter
De-Icing
Description
Fire Sprinkler System
Freeze Protection
Thermostats, controllers
and accessories
Pipe Freeze Protection
and Flow Maintenance
ElectroMelt System Surface Snow Melting and Anti-Icing Design Worksheet
Power Distribution
See Table 11.
Surface Snow
Melting – ElectroMelt
Freezer Frost
Heave Prevention
Step  Complete the Bill of Materials
Use the information recorded in this worksheet to complete the Bill of Materials.
Floor Heating
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
33 / 34
Technical Data
Sheets
THERMAL MANAGEMENT SOLUTIONS
WWW.PENTAIRthermal.COM
NORTH AMERICA
Europe, Middle East, Africa
Asia Pacific
Latin America
Tel:+1.800.545.6258
Fax:+1.800.527.5703
Tel:+1.650.216.1526
Fax:+1.650.474.7711
[email protected]
Tel:+32.16.213.511
Fax:+32.16.213.603
[email protected]
Tel:+86.21.2412.1688
Fax:+86.21.5426.2917
[email protected]
Tel:+1.713.868.4800
Fax:+1.713.868.2333
[email protected]
Pentair, DigiTrace, and ElectroMelt are owned by Pentair or its global affiliates. All other trademarks are the property of their respective owners.
Pentair reserves the right to change specifications without prior notice.
© 2009-2013 Pentair.
THERMAL MANAGEMENT SOLUTIONS
EN-RaychemElectroMeltSnowMelting-DG-H53393
11/13
34 / 34
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement