Danfoss Pipe Frost Protection Application guide

Document category | Product name

Electrical Heating

Pipe Frost Protection

Application manual

Let Danfoss do the work

Index

Danfoss Group is Denmark's largest industrial group. It is one of the world's
leading companies within heating, cooling and air-conditioning. The Danfoss
Group has more than 23000 employees and serves customers in more than 100
countries.

Danfoss is Europe’s leading brand of electrical cable heating systems and electric
pipe heating systems with over 70 years of experience. The production of
heating cables takes place in France and Poland while the head office is situated
in Denmark.

Pipe Frost Protection

This design guide presents Danfoss’s recommendations for design and
installation of frost protection for pipes. It provides guidance for heating cable
layout, electrical data and system configurations.

Following Danfoss’s recommendations will ensure energy efficient, reliable and
maintenance free solution for constant wattage heating cables with 20 year
warranty, self-limiting heating cables with 5 years of warranty.

1. Application briefing 4

2. System Description 5

3. Products 7

4. System design 11

5. Installation 20

6. Cases 28

Our quality management
system
and compliances

ISO 9001 TS 16949

ISO 14001

Along with full compliance with EU

directives and product approvals

1. Application
briefing

During the winter, problems with
freezing in fresh water, waste water,
cooling water, supply water and
sprinkler systems can be avoided by
internal or external pipe heating.

Pipes installed outdoor or inside
unheated premises, even if insulated,
can be subjected to low temperatures
that results in ice generation inside
pipes.

When water turns to ice its volume
expands and in closed pipes ice
becomes strong enough to cause pipe
bursting. This results in damages, water
leakage and costly repairs.

Danfoss heating systems provide
an affordable, easy to install and
adjustable solution in the form of a
thermostat regulated heating cable.

This solution provides a pipeline owner
with a safe, maintenance free and
sustainable system ensuring proper
performance for years.

Benefits

• Avoiding unforeseen repair costs: Frost

protection of pipes eliminates expensive repairs
and replacements after a long cold winter.

• Secures constant flow of water in pipes, even

in the coldest and unpredictable conditions.

• Any installation areas: Can be used on and in

pipes, indoor, outdoor and in ground.

• Approved for use in drinking water supply
systems.

• Reduced cost of installation in rocky and

other ground types, by alowing shallower
installation.

• Possibility for retrofitting of insulated pipes.

Danfoss’s pipe tracing systems
can be used for inside and outside
applications in individual pipes and
pipelines as well as for overhead and
buried pipelines.

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Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

2. System Description

Danfoss heating system provides
a versatile solution for water pipes
protection (including drinking water
pipelines) against freezing.

For on-pipe application:

ECflex constant wattage cables or
self-limiting cables (SLC) such as
ECpipeguard, ECpipeheat 10 V2
provide flexible and on-site cut-to­length solutions.

For in-pipe application:

ECaqua constant wattage cables.

The system is regulated by means
of ECtemp 330 or 610 electronic
thermostats. This is needed for
constant wattage cables and
strongly advised for self-limiting
cables (SLC) to prevent energy
consumption during standby
periods.

To ensure energy efficient solution
the use of an aluminum tape for
cable installation, thermal insulation
of pipes and electronic thermostats
for control are essential.

electrical

connection box

temperature

sensor

heating

Electronic thermostats ECtemp have
a sensor placed directly on pipe to
be protected under its insulation,
and ensure optimal operation with
minimal energy consumption.

-20°C

water pipe

cable

sewer

drain

thermostat

ECtemp 330

thermostat

ECtemp 610

thermostat

ECtemp 330

in electrical

connection box

fire fighting installation

-10°C

electrical

connection box

Cold water installation

insulaiotn
aluminum tape
heating cable
sand
soil / ground

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

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Pipe tracing

Sensor
Heating cable
Insulation
Fitting
Valve
Aluminum tape

In-pipe frost protection

Insulation
Heating Cable

Subsurface pipe tracing

Concrete breeze block (not always installed)
and/or XPS insulation (not always installed)
Danfoss heating cable
Sand bed
Soil

Heating cables can be used with either
metal or plastic pipes (e.g. PVC, PE, PP
etc.). Plastic pipes may have limitations
with regard to the output of a heating
cable installed.

For more information please refer to
the design section of this Application
Manual as well as confirm temperature
limits for plastic pipes with your
supplier.

Installations are divided in two general
application categories:

• Inside buildings

• Outside buildings

The outside application category can
be additionally divided into:

• in air

• in ground installation, as shown on
the pictures above.

Installation inside buildings

Water supply pipes installed inside
buildings, where temperature may
fall below 0 °C, e.g. unheated parking
areas.

For such applications installation of
electrical heating cables to ensure
sustainable water flow and to prevent
icing and subsequent pipe bursting is
strongly advisable and in many cases
required by law.

For further detailes investigate local
buidling norms.

Outside above ground installation

Pipes installed outside buildings are
especially in need of frost protection.

The primary protection is ensured
by insulation but often to protect
pipes in extreme weather conditions
or in course of economic feasibility
it's advantageous to install an
electrical heating system (cables and
thermostat).

Examples of such installations can be
found: on roofs of shopping arcades,
office buildings, hotels or utility
buildings like water stations.

Outside in-ground installation

Water pipes insulated and protected
with electrical heating systems can be
installed in ground at a shallower depth.

In some areas, where the ground is
composed of solid rock, this is the most
economically feasible solution.

Location of electrical heating cables
has to be clearly marked following
local electricity laws. Marking shall
include at least a yellow or red warning
label indicating a supply voltage level.
Additionally, if the cable is not protected
by a concrete block, or similar, a thick
plastic tape should be placed on top
and slightly above the cable for its entire
length. This is to minimize the possibility
of mechanical damage during possible
excavation activities in the future.

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Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

3. Products

Heating cables

The following heating cables can be
used for protection of water pipe
heating systems:

Heating cables for on-pipe installation:

• Resistive (constant wattage):
ECflex 10T, ECflex 18T;
ECbasic 20S.

• Self-limiting cables (SLC;
variable wattage):
ECpipeheat 10 V2,
ECpipeguard 10/SLPG-10,
ECpipeguard 25/SLPG-25,
ECpipeguard 33/SLPG-33;
ECiceguard 18/SLIG-18.

Heating cables for in-pipe installation:

• ECaqua 9T.

Mentioned as "in-pipe installation"
is approved for use in contact with
drinking water.

The heating cable is relatively stiff,
which makes the installation easier.
The polyethylene coating prevents
any output or taste alteration of
drinking water.

Self-limiting heating cables are
equipped with a temperature
sensitive resistant element between
two parallel copper conductors.
When conductors are connected to
the mains, the current flows through
the temperature sensitive element
which starts heating. As the element
is heated, the resistance value rises
causing the current decrease and
then the heating is reduced. This
explains the self-limiting output
effect.

Such independent output regulation
takes place on the entire cable based
on the actual ambient temperature.
When the ambient temperature rises,
the cable heating output is reduced.

This self-limiting capability allows
avoiding cable overheating even in
case if two cables cross or touch each
other.

Autonomous power supply of self­limiting heating cables allows their
shortening or extending in any place.
This simplifies cable planning and
installation.

In order to limit power consumption
the heating cable should switch on/
off if it’s length exceeds approx. 3 m,
e.g. by using a ECtemp thermostat.

Resistive cables

ECbasic

ECflex

Self-limiting cables

ECpipeheat 10 V2/ SLPH-10

ECpipeguard 10/SLPG-10

ECpipeguard 25/SLPG-25

ECpipeguard 33/SLPG-33

ECaqua 9T

ECiceguard 18/SLIG-18

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

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Thermostats

To control a pipe heating system
ECtemp 330 (5…45 °C) thermostat
with DIN rail attachment or
wall/pipe mounted ECtemp 610
(IP44) are recommended.

All thermostats are equipped with
wire temperature sensors in set –
NTC 15 kOhm @ 25 °C, 3 m.

Fixing & Connection

Attaching cable to metal or plastic
pipes is recommended by means of
adhesive aluminum tape.

A large choice of connection sets,
shrink tube or system-sets is available
for connection and interconnection
of heating cables (including SLC) to
power supply and to each other. See
also the next page.

A larger variety of connecting
accessories (fixed as well as based
on shrinking-tube) for self-limiting
heating cables is available.

For more information please refer
to the Danfoss product program or
contact your local Danfoss provider.

SLC to box connection set (#19400100)

SLC connection set (#19400126)

ECtemp 330 ECtemp 610

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Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

Glued aluminum tape with warning signs
(#19805076)

Connection box (#19400167)

Selection chart: Danfoss Connecto for heating cables with braiding

Article no. Illustration Name Description

088L0416 Connecto B-S

088L0414 Connecto B-C

088L0417 Connecto B-T

088L0418 Connecto B-TE2

088L0419 Connecto B-TE3

Heating cable connection with 1,5 m

power cable and end terminal

Heating cable slice/extension for con-

necting two heating cables

Heating cable T-branch as a T-junction for

three heating cables and 1 end terminal

Heating cable double connection with 1,5

m power cable and 2 end terminals

Heating cable T-branch with 1,5 m power

cable and 3 end terminals

088L0420 Connecto B-X

088L0413 Connecto B-A

088L0415 Connecto B-E Heating cable end terminal

Danfoss Connecto system
installation steps

1. Cut the heating cable straight

2. Push the heating cable in

3. Twist untill closed

Heating cable X-branch for 4 heating

cables incl. 2 end terminals

Heating cable connection with power

cable 1,5 m without end terminal

Connecto B-C Connec to B-TE2 Connecto B-X

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

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