DREXAN HeatTracer Design/install Manual

HD110301-1 Rev2

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Fire Sprinkler Freeze Protection

Design / Install Guide

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CONTENTS

Introduction Page 3

System Overview Page 4

Fire Suppression System Freeze Protection Applications Page 5

Typical Pipe Freeze Protection System Page 5

Fire Supply Lines Page 6

Sprinkler Standpipes Page 8

Branch Lines with Sprinklers Page 9

Freezer Applications Page 10

Fire Suppression System Freeze Protection Design Guide Page 11

STEP 1 – Collect the Required Information for Each Line Page 11

STEP 2 – Design Considerations Page 12

STEP 3 – Electrical Requirements Page 13

STEP 4 – Selecting Cable Power Output Page 13

STEP 5 – Cable Components Page 17

STEP 6 – Power Distribution Page 18

Installing Self-Regulating Cable Page 19

Testing Self-Regulating Cable Page 21

Heating Cable Test Report Page 22

Troubleshooting Self-Regulating Cable Page 23

Fire Sprinkler System Freeze Protection
Design / Install Guide

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INTRODUCTION

This design guide and installation manual from Drexan HeatTracer provides recommendations for
designing a pipe freeze protection system for fire sprinkler piping, using Drexan HeatTracer
MultiTrace cables. It provides system design and performance data, information on heat tracing
monitoring and control, electrical sizing information, and various configuration recommendations.
This design guide assumes the fire protection system has been designed by others qualified in the
art.

MultiTrace is certified to all CSA / UL (CUS) standards for use throughout North America, as well as
ATEX 2014/34/EU for global applications and is suitable for both metal and non-metal pipes, tanks
and vessels. (see p.17).

This guide does not cover the following applications:

• Hazardous locations as defined in the National / Canadian Electric Code

• Supply voltages other than 100-130V or 208-277V

For assistance with application requirements that differ from those addressed in this document,
contact your Drexan representative or Drexan directly at 1-800-663-6873.

The following instructions will provide you with a step-by-step procedure for determining the best
solution for your fire sprinkler system freeze protection applications. An improperly designed and
installed heat tracing system could result in cable failure and possible physical injury.

The installation manual provides general guidance for installing the heating cable and components
on fire sprinkler piping. Additional installation instructions are included with the connection kits,
controllers, and accessories. If you are missing any required documents, you can download them
from the on-line document library at www.drexan.com.

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SYSTEM OVERVIEW

Drexan HeatTracer MultiTrace self-regulating cable is designed for freeze protection of above
ground and buried supply pipes, fire standpipes, branch lines and branch lines containing sprinklers
when run in areas potentially exposed to freezing temperatures.

Drexan offers 4 MultiTrace nominal cable power output options for fire sprinkler systems: 3W, 5W,
8W and 10W per foot1 for applications using 100-130V and 208-277V power. Selection of the
correct power output for a given line size will ensure sprinkler systems do not overheat and that
electrical energy is efficiently used, while providing the required, reliable freeze protection.

A correctly designed and specified system will comprise the following:

 Heating cable correctly selected for the line size at design minimum ambient temperatures
 Power connections, tees and end seals based on piping configuration
 Monitoring and control system
 Power distribution panels complete with appropriate ground fault equipment protection
 Accessories including attachment tapes and warning labels
 Tools necessary for a complete installation and commissioning tests

Approvals

Drexan HeatTracer MultiTrace is CSA / UL (CUS) certified for use on fire suppression systems in North
America. The system covered in this manual includes supply lines, stand pipes, branch lines and
sprinkler heads.

1

at 50 degrees F

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FIRE SUPPRESSION SYSTEM FREEZE PROTECTION APPLICATIONS

Properly designed freeze protection systems maintain water temperature at a minimum of 40°F/4°C
to prevent fire suppression piping from freezing.

Fire Suppression System Freeze Protection Applications

A typical freeze protection system includes the heating cables, connection kits, cable monitoring
and temperature control, and power distribution.

FIG. 1 – TYPICAL FIRE / FREEZE PROTECTION SYSTEM

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Fire Supply Lines

MultiTrace is designed to maintain fire supply lines at 40°F/4°C in areas subject to freezing.

FIG. 2 – ABOVE GROUND SUPPLY PIPING

Application Requirements

The system complies with Drexan HeatTracer design and installation requirements for above ground
general water piping given the following conditions are met:

 Heating cable is permanently secured to insulated metal pipes using TAPE-GCR-HT glass tape

or to plastic pipes using TAPE-AL aluminum tape

 The system is controlled by a Controller with integrated ground fault protection with alarm

contacts connected to a fire control panel

 Heating cable is installed per manufacturer’s instructions with approved connection kits.

Approvals

CSA / UL (CUS) certified for non-hazardous locations.

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FIG. 3 – TYPICAL BURIED PIPING SYSTEM

Application Requirements

The system complies with Drexan HeatTracer design and installation requirements for buried piping
given the following conditions are met:

 The line is buried at least 2 feet/0.7 m deep
 All heating cable connections are made above ground
 The power connection and end seal connections are made above grade in Drexan HeatTracer

connection kits

 Heating cable is protected from the pipe to the power connection box in CSA certified water-

sealed conduit with a minimum diameter of ¾” suitable for the location

 The system is controlled by a Controller with integrated ground fault protection with alarm

contacts connected to a fire control panel

 Closed cell waterproof thermal insulation with fire retardant waterproof covering approved

for direct burial is used over the cable and pipe

 Heating cable is installed per manufacturer’s instructions with approved connection kits

Approvals

CSA / UL (CUS) certified for non-hazardous locations.