nvent RAYCHEM XL-Trace Guide

nVent.com | 1RAYCHEM-DG-H58489-XLTraceFireSprinkler-EN-1904
This step-by-step design guide provides the tools necessary to design a
RAYCHEM XL-Trace fire sprinkler freeze protection system. For other
applications or for design assistance, contact your nVent representative or call
(-. Also, visit our web site at nVent.com.
CONTENTS
INTRODUCTION...................................................................................... 1
How to Use this Guide........................................................................................................... 2
Safety Guidelines.................................................................................................................... 2
Warranty................................................................................................................................... 2
SYSTEM OVERVIEW ............................................................................... 3
Approvals ................................................................................................................................. 3
Self-Regulating Heating Cable Construction.................................................................... 4
FIRE SUPPRESSION SYSTEM FREEZE PROTECTION APPLICATIONS ... 5
Typical Pipe Freeze Protection System ............................................................................. 5
Fire Supply Lines .................................................................................................................... 6
Sprinkler Standpipes ............................................................................................................. 8
Branch Lines with Sprinklers ............................................................................................... 9
Freezer Application.............................................................................................................. 10
FIRE SUPPRESSION SYSTEM FREEZE PROTECTION DESIGN.............. 11
Design Step by Step............................................................................................................. 11
Step 1 Determine design conditions and pipe heat loss...................................... 12
Step 2 Select the heating cable................................................................................. 17
Step 3 Determine the heating cable length............................................................. 19
Step 4 Determine the electrical parameters...........................................................21
Step 5Select the connection kits and accessories ..............................................24
Step 6Select the control system ..............................................................................29
Step 7Complete the Bill of Materials..............................................................................30
INSTALLATION AND MAINTENANCE ................................................... 31
XL-TRACE SYSTEM FIRE SPRINKLER SYSTEM FREEZE
PROTECTION DESIGN WORKSHEET.....................................................32
INTRODUCTION
This design guide presents nVent recommendations for designing an XL-Trace
pipe freeze protection system for fire sprinkler piping. It provides design and
performance data, control options, electrical sizing information, and application
configuration suggestions. This guide does not give information on how to design
your fire protection system.
This guide does not cover applications in which any of the following conditions exist:
• Hazardous locations, as defined in national electrical codes
• Supply voltage other than  V or – V
If your application conditions are different, or if you have any questions,
-.
FIRE SPRINKLER SYSTEM FREEZE
PROTECTION — XL-TRACE SYSTEM

RAYCHEM-DG-H58489-XLTraceFireSprinkler-EN-1904 nVent.com | 2
How to Use this Guide
This design guide takes you step by step through designing a freeze protection
system for fire suppression piping. Following these recommendations will result in
a reliable, energy-efficient system.
OTHER REQUIRED DOCUMENTS
This guide is not intended to provide comprehensive installation instructions. For
complete system installation instructions, please refer to the following additional
required documents:
• XL-Trace System Installation and Operation Manual (H)
• Additional installation instructions are included with the connection kits,
controllers, and accessories
If you do not have the above documents, you can obtain them from the nVent web
site at nVent.com.
For products and applications not covered by this design guide, please contact
your nVent representative or call () -.
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 connection kits 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

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 nVent, 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
nVent standard limited warranty applies to all products.
An extension of the limited warranty period to ten () years from the date of
installation is available if a properly completed online warranty form is submitted
within thirty () days from the date of installation. You can access the complete
warranty on our web site at nVent.com.

RAYCHEM-DG-H58489-XLTraceFireSprinkler-EN-1904 nVent.com | 3
SYSTEM OVERVIEW
The XL-Trace system is designed to freeze protect aboveground and buried supply
pipes, fire standpipes, branch lines and branch lines containing sprinklers when run
in areas subject to freezing.
nVent offers the option of three self-regulating heating cables with the
XL-Trace system; XL, XL, and XL for applications using  V and –
power supplies. The XL-Trace system is based on self-regulating heating cable
technology whereby the heating cable’s output is reduced automatically as the pipe
warms; eliminating the possibility of sprinkler system overheating.
An XL-Trace system includes the heating cable, power connection, splice, tee
connections, controls, power distribution panels, accessories, and the tools
necessary for a complete installation.
Approvals
NFPA  (Standard for the Installation of Sprinkler Systems) allows Listed electrical
heat tracing to freeze protect fire suppression systems including supply lines,
standpipes and branch lines containing sprinklers. XL-Trace is c-CSA-us Certified
for use on fire suppression systems under CSA C.No. - for Canada and
IEEE .- for the US. The system covered in this manual includes supply
lines, stand pipes, branch lines and sprinkler heads.

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Self-Regulating Heating Cable Construction
XL-Trace self-regulating heating cables are comprised of two parallel nickel-
plated bus wires in a cross-linked polymer core, a tinned copper braid, and a
fluoropolymer or polyolefin outer jacket. These cables are cut to length, simplifying
the application design and installation.
Nickel-plated copper bus wire
Self-regulating conductive core
Modified polyolefin inner jacket
Tinned-copper braid
Polyolefin or
fluoropolymer outer jacket
Fig. 1 XL-Trace 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.

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.

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.
At high temperature,
there are few
conducting paths
and output is
correspondingly
lower, conserving
energy during
operation.
At moderate temperature,
there are fewer conducting
paths because the heating
cable efficiently adjusts by
decreasing output, eliminating
any possibility of overheating.
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.
Temperature
Resistance
Power
Temperature
Constant wattage
Constant wattage
Self-regulating
Self-regulating
Fig. 2 Self-regulating heating cable technology

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FIRE SUPPRESSION SYSTEM FREEZE PROTECTION APPLICATIONS
A freeze protection system is designed to maintain water temperature at
°F (°C) to prevent fire suppression piping from freezing.
Typical Pipe Freeze Protection System
A typical freeze protection system includes the XL-Trace self-regulating heating
cables, connection kits, temperature control, and power distribution.
Standpipe
Thermal insulation
Control valves
in heated enclosure
RayClic-PC
power connection
RayClic-S splice
RayClic-LE
lighted end seal
Ambient sensing RTD
Ground
XL-Trace
Power
distribution
panel
Fire
alarm
panel
C910-485
electronic
controller
Line sensing RTD
Fig. 3 Typical XL-Trace pipe freeze protection system

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Fire Supply Lines
XL-Trace is designed to maintain fire supply lines at °F (°C) in areas subject to
freezing.
ABOVEGROUND SUPPLY PIPING
RayClic-PC
power connection
Junction
box
XL-Trace
heating cable
RayClic-S
splice
RayClic-T
tee
Insulation
RayClic-LE
lighted end seal
(optional)
RayClic-E
end seal
C910-485
Electronic controller
Fig. 4 Typical aboveground supply piping system
Application Requirements
The system complies with nVent requirements for aboveground general water
piping when:
• The heating cable is permanently secured to insulated metal pipes with
GT- aluminum tape.
• nVent RAYCHEM C- or ACS- controllers with integrated ground-fault
protection and alarm contacts are used and are connected to a fire control panel.
• The heating cable is installed per manufacturer’s instructions with approved
nVent RAYCHEM connection kits. See Table  on page 25 and the XL-Trace
).
Approvals
c-CSA-us Certified for nonhazardous locations.
5XL1-CR, -CT
5XL2-CR, -CT 8XL1-CR, -CT 8XL2-CR, -CT
5XL1-CR, -CT
5XL2-CR, -CT 8XL1-CR, -CT 8XL2-CR, -CT 12XL2-CR, -CT
-w

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BURIED PIPING
Temperature sensor
Insulation
Conduit
XL-Trace
heating cable
with -CT jacket
Ground
Alternate
power connection
Alternate
end seal
Ground
Wall
RayClic-LE*
RayClic-PC*
Junction box
RayClic-E
end seal
Conduit
Wall
with wall
mounting
bracket
with wall
mounting
bracket
FTC-XC
power
connection
*To protect the heating cable, run cable
inside Convolex tubing between the
conduit and the RayClic connection kits.
C910-485
Electronic controller
Conduit for
temperature
sensor
Fig. 5 Typical buried piping system
Application Requirements
The system complies with nVent requirements for use on buried insulated metal or
plastic pipe when:
• The heating cable is permanently secured to insulated metal pipes with GT-
glass tape or to plastic pipes using AT- aluminum tape.
• The pipeline is buried at least -feet deep.
• The heating cable has a fluoropolymer outer jacket (-CT).
• All heating cable connections (power, splice, tee, and end termination) are made
aboveground. No buried or in-conduit splices or tees are allowed.
• The power connection and end seal are made in UL Listed and CSA Certified
junction boxes, or nVent RAYCHEM RayClic connection kits, above grade.
• The heating cable is protected from the pipe to the power connection box in
/-inch diameter)
suitable for the location.
• C- or ACS- controllers with integrated ground-fault protection and

• Closed-cell, waterproof thermal insulation with fire-retardant, waterproof
covering approved for direct burial is used.
• The heating cable is installed per manufacturer’s instructions with approved
nVent connection kits. See Table  on page 27 and the XL-Trace System
Installation and Operation Manual (H).
Approvals
c-CSA-us Certified for nonhazardous locations.
5XL1-CT
5XL2-CT 8XL1-CT 8XL2-CT
5XL1-CT
5XL2-CT 8XL1-CT 8XL2-CT 12XL2-CT
-w

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Sprinkler Standpipes
XL-Trace is designed to maintain fire suppression system standpipes at °F (°C)
in areas subject to freezing.
FOR ABOVEGROUND STANDPIPES
Standpipe
Thermal insulation
Control valves
in heated enclosure
RayClic-PC
power connection
RayClic-S splice
RayClic-LE
lighted end seal
Ambient sensing RTD
Ground
XL-Trace
Power
distribution
panel
Fire
alarm
panel
C910-485
electronic
controller
Refer to Branch
Lines with
Sprinkler section
for information on
heat tracing
sprinkler heads.
Line sensing RTD
Fig. 6 Standard sprinkler standpipe heating system layout
Application Requirements
The system complies with nVent requirements for freeze protection of sprinkler
system piping when:
• The heating cable is permanently secured to insulated metal pipes with GT-
glass tape or to plastic pipes using AT- aluminum tape.
• Schedule , , , or  steel sprinkler standpipe up to and including  inches
in diameter is used.
• UL Listed fiberglass or closed cell flame-retardant insulation with weatherproof
cladding is used.
• C- or ACS- controllers with integrated ground-fault protection and
alarm contacts are used and are connected to a fire control panel.
• The heating cable is installed per manufacturer’s instructions with approved
nVent connection kits. See Table  on page 25 and the XL-Trace System
Installation and Operation Manual (H).
Approvals
c-CSA-us Certified for nonhazardous locations.
5XL1-CR, -CT
5XL2-CR, -CT 8XL1-CR, -CT 8XL2-CR, -CT
5XL1-CR, -CT
5XL2-CR, -CT 8XL1-CR, -CT 8XL2-CR, -CT 12XL2-CR, -CT
-w

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Branch Lines with Sprinklers
XL-Trace is designed to maintain branch lines containing sprinklers at °F (°C) in
areas subject to freezing.
Power
connection
Splice
Line sensing
RTD
Cross
End seal
Tee
Insulation
Sprinkler
C910-485
RayClic-LE
lighted end seal
(optional)
Junction
box
Ambient
sensing
RTD
Fig. 7 
Application Requirements
The system complies with nVent requirements for fire suppression branch lines
with sprinklers when:
• The heating cable is permanently secured to metal pipes with GT- glass tape,
or to plastic pipes using AT- aluminum tape.
• C- or ACS- controllers with integrated ground-fault protection with
alarm contacts are used and are connected to a fire control panel.
• The sprinkler design accounts for the sprinkler shadow created by the outer
diameter of the thermal pipe insulation.
• Closed-cell, waterproof thermal insulation with fire-retardant, waterproof
covering is used.
• The heating cable is installed per manufacturer’s instructions with approved
nVent connection kits. See Table  on page 27 and the XL-Trace System
Installation and Operation Manual (H).
• Additional heating cable is installed to compensate for sprinkler heads,
sprigs, valves and pipe supports as detailed in the Table on page 20 of
this document and the XL-Trace System Installation and Operation Manual
(H).

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Approvals
c-CSA-us Certified for use in U.S. and Canada in nonhazardous locations.
5XL1-CR, -CT
5XL2-CR, -CT 8XL1-CR, -CT 8XL2-CR, -CT
-w
Freezer Application
XL-Trace is designed to keep condensate in dry sprinklers from freezing and may
be installed in freezers located in areas subject to freezing.
Power
distribution
panel
Fire
alarm
panel
C910-485
electronic
controller
RTDThermal insulation
Freezer
Building
XL-Trace
Fig. 8 
Application Requirements
The system complies with nVent requirements for fire suppression systems for
freezer applications when:
• The system is for freezer and freezer within a freezer applications.
• The heating cable is permanently secured to metal pipes with GT- glass tape,
or to plastic pipes using AT- aluminum tape.
• C- or ACS- controllers with integrated ground-fault protection and alarm

• Closed-cell, waterproof thermal insulation with fire-retardant, waterproof
covering is used for pipes and sprigs in areas subject to freezing.
• The sprinkler design accounts for sprinkler shadow created by the outer
diameter of the thermal pipe insulation.
• The heating cable is installed per manufacturer’s instructions with approved
nVent connection kits. See Table  on page 27 and the XL-Trace System
Installation and Operation Manual (H).
• Additional heating cable is installed to compensate for sprinkler heads, sprigs,
valves and pipe supports as detailed in the Table on page 20 of this document
and the XL-Trace System Installation and Operation Manual (H).
Approvals
c-CSA-us Certified for use in U.S. and Canada in nonhazardous locations.
5XL1-CR, -CT
5XL2-CR, -CT 8XL1-CR, -CT 8XL2-CR, -CT
-w