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.

4

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

5

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.

6

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

7

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

8

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

9

Product overview for the Pipe Frost Protection

Product Options Description

Resistive heating cable
ECflex

Resistive heating cable
ECbasic

Resistive heating cable
ECaqua

Self-limiting heating cable
Danfoss iceguard

Self-limiting heating cable
Danfoss pipeguard

Self-limiting heating cable inside pipe
Danfoss pipeheat 10 V2

Danfoss thermostat ECtemp 330 (5…45 °C)

Danfoss thermostat ECtemp 610 -10…+50 °C, 10 A, IP44, wall/pipe installation

Assembly kit

Fixing Aluminum tape (Alutape)

ECflex 10T, 230 V;
ECflex 18T, 230 V

ECbasic 20, 230 V;
EFSIC 20, 400 V, on drum

ECaqua 9T
with 3/4+1" Pipe fitting

ECiceguard 18 (SLIG-18), on drum

ECpipeguard 10 (SLPG-10), on drum
ECpipeguard 25 (SLPG-25), on drum
ECpipeguard 33 (SLPG-33), on drum

ECpipeheat 10 V2 (SLPH-10) with plug, 2-25 m.
Accessory:
3/4"+1" Pipe fitting (10 bar @ 23 °C)

Connecto
and other assembly kits

Twin conductor, 100% screen.
10 or 18 W/m (230 V); Ø 6,9 mm.
DIN IEC 60800:2009 M2

Single conductor, wire screen.
20 W/m (230 V); Ø 5,5 mm.
DIN IEC 60800:1992

Twin conductor, wire screen,
9 W/m (230 V); Ø 5,7 mm
Approved for use in drinking water.

18 W/m @ 0 °C.
11,8 x 5,8 mm.

10 W/m @ 10 °C.
25 W/m @ 10 °C.
33 W/m @ 10 °C.
11,8 x 5,8 mm

10 W/m @ 10 °C, 100% screen.
7,7 mm × 5,3 mm.

5…45 °C, 16 A, IP20,
DIN rail

For self-limiting cables

Glued aluminum tape 38 mm x 50 m;
0,06 mm; max. 75 °C

For details please refer to the Danfoss Catalogue.
Various specific assembly kits are available.

10

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

4. System design

Output of heating cables installed
on pipe should not be less than the
calculated pipe surface heat loss
multiplied by 1,3 safety factor.

In most cases 10 W/m output is enough if:

• the pipe diameter does not exceed
50 mm,

• the temperature of surroundings
does not fall below -30 °C.

• the required temperature inside the
pipe is 5 °C.

In other words, for the above
conditions, the only one 10 W/m cable
line (ECflex 10T, etc.) is required.

• the insulation thickness is at least
the same as the pipe diameter,

Frost protection of pipe systems [W/m]

To define the heat loss follow the pipe
The table below shows the heat loss
for 1 meter of pipe (q

) for various

pipe

pipe dimensions, insulation thicknesses
and temperatures.

diameter (in [mm] or [inch]) at the top

bar of the table towards the row with

the insulation thickness and using the

appropriate temperature

Required minimal outputs in [W/m], for straight pipelines (without flanges, valves or T-branches).

Inside pipe

diameter

Outside pipe

diameter*

Insulation

thickness

10 mm

20 mm

30 mm

40 mm

50 mm

75 mm

* NPS - Nominal Pipe Size, DN - diamètre nominal/nominal diameter/Durchmesser nach Norm.
Values in table can be calculated with help of formula on next page (chapter 4.1)

inch (NPS*) ½ ¾ 1 1¼ 1½ 2 2½ 3 3½ 4 4½ 5 6 8 10 12

mm (DN*) 15 20 25 32 40 50 65 80 90 100 115 125 150 200 250 300

mm 21 27 34 42 48 60 73 89 102 114 127 141 168 219 273 324

ΔT, °C Heat loss for 1 meter of pipe, W/m ( λ = 0,04, Safety factor = 1,3)

20 9,8 11,8 14,1 16,8 18,8 22,7 27,0 32 36 40 45 49 58 75 92 109
25 12,2 14,7 17,6 21,0 23,4 28,4 34 40 46 51 56 62 73 93 115 136
30 14,6 17,7 21,2 25,2 28,1 34 40 48 55 61 67 74 87 112 139 164
40 19,5 23,6 28,2 34 38 45 54 64 73 81 89 98 116 149 185 218
60 29,3 35 42 50 56 68 81 97 109 121 134 148 174 224 277 327
80 39,0 47 56 67 75 91 108 129 146 162 179 197 232 299 370 436

100 48,8 59 71 84 94 114 135 161 182 202 223 246 290 374 462 545

20 6,1 7,2 8,4 9,8 10,8 12,8 14,9 17,6 19,7 21,7 23,9 26,2 31 39 48 56
25 7,7 9,0 10,5 12,2 13,5 16,0 18,7 22,0 24,7 27,1 30 33 38 49 60 70
30 9,2 10,8 12,6 14,6 16,2 19,2 22,4 26,4 30 33 36 39 46 58 72 84
40 12,2 14,4 16,8 19,5 21,6 25,6 30 35 39 43 48 52 61 78 96 112
60 18,4 21,6 25,2 29,3 32 38 45 53 59 65 72 78 92 117 143 168
80 24,5 28,7 34 39 43 51 60 70 79 87 95 105 122 156 191 224

100 30,6 36 42 49 54 64 75 88 99 109 119 131 153 195 239 281

20 4,8 5,6 6,4 7,4 8,1 9,4 10,9 12,7 14,1 15,4 16,9 18,4 21,4 27,0 33 38
25 6,0 7,0 8,0 9,2 10,1 11,8 13,6 15,8 17,6 19,3 21,1 23,0 26,7 34 41 48
30 7,3 8,4 9,6 11,0 12,1 14,1 16,3 19,0 21,2 23,2 25,3 27,6 32 40 49 58
40 9,7 11,2 12,8 14,7 16,1 18,8 21,8 25,3 28,2 31 34 37 43 54 66 77
60 14,5 16,7 19,3 22,1 24,2 28,3 33 38 42 46 51 55 64 81 99 115
80 19,4 22,3 25,7 29,4 32 38 44 51 56 62 68 74 86 108 131 154

100 24,2 27,9 32 37 40 47 54 63 71 77 84 92 107 135 164 192

20 4,2 4,7 5,4 6,1 6,7 7,7 8,8 10,2 11,3 12,3 13,4 14,5 16,8 21,0 25,4 29,6
25 5,2 5,9 6,7 7,7 8,3 9,6 11,0 12,7 14,1 15,4 16,7 18,2 21,0 26,2 32 37
30 6,2 7,1 8,1 9,2 10,0 11,6 13,2 15,3 16,9 18,4 20,1 21,8 25,2 31 38 44
40 8,3 9,5 10,8 12,2 13,3 15,4 17,7 20,4 22,6 24,6 26,7 29,1 34 42 51 59
60 12,5 14,2 16,2 18,4 20,0 23,1 26,5 31 34 37 40 44 50 63 76 89
80 16,6 19,0 21,6 24,5 26,6 31 35 41 45 49 53 58 67 84 102 118

100 20,8 23,7 27,0 31 33 39 44 51 56 61 67 73 84 105 127 148

20 3,7 4,2 4,8 5,4 5,8 6,7 7,6 8,7 9,6 10,4 11,2 12,2 14,0 17,4 20,9 24,3
25 4,7 5,3 6,0 6,7 7,3 8,3 9,5 10,8 11,9 13,0 14,1 15,2 17,5 21,7 26,2 30,4
30 5,6 6,3 7,1 8,0 8,7 10,0 11,4 13,0 14,3 15,6 16,9 18,3 21,0 26,0 31 36
40 7,5 8,4 9,5 10,7 11,6 13,3 15,1 17,3 19,1 20,7 22,5 24,4 28,0 35 42 49
60 11,2 12,7 14,3 16,1 17,4 20,0 22,7 26,0 28,7 31 34 37 42 52 63 73
80 14,9 16,9 19,0 21,4 23,2 26,6 30 35 38 41 45 49 56 69 84 97

100 18,6 21,1 23,8 26,8 29,0 33 38 43 48 52 56 61 70 87 105 121

20 3,1 3,5 3,9 4,3 4,6 5,2 5,8 6,6 7,2 7,8 8,4 9,0 10,2 12,5 14,9 17,2
25 3,9 4,3 4,8 5,4 5,8 6,5 7,3 8,3 9,0 9,7 10,5 11,3 12,8 15,6 18,6 21,5
30 4,7 5,2 5,8 6,4 6,9 7,8 8,8 9,9 10,8 11,7 12,6 13,5 15,4 18,8 22,4 25,7
40 6,2 6,9 7,7 8,6 9,2 10,4 11,7 13,2 14,4 15,6 16,8 18,0 20,5 25,0 29,8 34
60 9,3 10,4 11,6 12,9 13,8 15,6 17,5 19,8 21,7 23,3 25,1 27,0 31 38 45 51
80 12,5 13,9 15,5 17,2 18,4 20,9 23,4 26,4 28,9 31 34 36 41 50 60 69

100 15,6 17,4 19,3 21,5 23,0 26,1 29,2 33 36 39 42 45 51 63 75 86

Note. For plastic pipes the linear

output of resistive heating cables
should not exceed 10 W/m. This
restriction does not apply to self­limiting cables (SLC).

Following pages will help step-by-step
to make a right design choice.

difference you will find the heat loss
value at the crossing point.
For this table λ of insulation material
is 0,04 W/m·K (e.g. mineral wool) and
safety factor is 1,3.

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

11

4.1. Step-by-step system design

Following pages provide an easy step­by-step design guide for selection of a
Danfoss pipe frost protection system.

The recommendations are provided
relate both constant wattage cables
and self-limiting cables, as well as
thermostats and accessories.

Step 1 2 3 4 5

Step 1 2 3 4 5

Heat loss calculation

Product selection

The detailed example is provided at
the end of this chapter.

Step 1 2 3 4 5

The most important factors to define
the pipe heat losses are the following:

• Pipe diameter

• Insulation thickness

• Difference between inside (desired

maintained temperature) and
outside pipe temperatures (e.g.
outdoor) temperature of the
installation site.

Step 1 2 3 4 5

Step 1 2 3 4 5

Step 1 2 3 4 5

Heat loss calculation

Cable length selection

Regulator selection

Accessories selection

t

a

t

p

The following formula is used for
heat losses calculation for total length
of a pipe to be protected:

Q [W ] =

2 · π · λ · l · (tu - to)

ln(D/d)

 1, 3 ,

where:

D - Outside pipe diameter incl. insulation, [m],
d - Pipe diameter without insulation, [m],
l - Total length of pipe, [m],
tp - Desired maintained temperature, [°C],
ta - Outside temperature, [°C],
λ - Thermal conductivity of insulation, [W/m·K],
1,3 - Safety factor.

ln(D/d)

(D/d)

Heat loss values from the table on
λ value for standard insulation material
(like glass wool or styropor), is set to
0,04 W/m·K.

the previous page calculated by the

above formula and divided by total

pipe length. The obtained values are

in [W/m].

12

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

0,0

1,0

0,4

1,5

0,7

2,0

0,9

2,5

1,1

3,0

1,3

3,5

1,4

4,0

d

D

1,5

1,6

1,8

1,9

2,1

2,2

2,3

4,5

5,0

6,0

7,0

8,0

9,0

10,0

15,0

Natural logarithm (ln) values for D/d
ratio: X = D/d.

2,7

3,0

20,0

3,2

25,0

Step 1 2 3 4 5

Product selection

Constant wattage heating cables

Are typically used in case of simple
straight pipe lines installed in a similar
thermal environment.

In such cases selection of the heating
cable directly depends on the pipe
length.

In case of installation of new pipes, or
longer pipe lines, the use of on-pipe
heating cables is preferable.

For shorter or existing pipes installation
of in-pipe heating cables is the only
feasible or available choice.

There are two different cables for
selection with different linear output
(10 W/m or 18 W/m). It's necessary
to choose a heating cable with
output equal or higher than the one
calculated by the formula (including
1,3 safety factor).

Cable outputs are calculated for 230 V.
For 220 V the displayed output value in
[W] shall be multiplied by 0,91 factor.
E.g. ECflex 10T, 60 m with output of
600 W at 230 V, has the output of only
546 W at 220 V.

Example (see also Step 1)

• Pipe diameter d = 65 mm

• Insulation thickness = 20 mm

• Thermal conductivity value for
insulation λ = 0,04

• Desired temperature tu = +10 °C

• Minimum outside temperature
to = -20 °C

Heat loss Q is calculated with help of
formula from Step 1 or from table on
page 11: Q = 16 W/m.

The choice is for cable with linear
output ≥ 16 W/m: ECflex 18T
(18 W/m).

ECf lex 10 T

Output

[W]

100 10
205 20
290 30
390 40
505 50
600 60
695 70
795 80
920 90

990 100
1220 120
1410 140

Length

[m]

ECflex 18T

Output

[W]

130 7,3
180 10
270 15
395 22
535 29

615 34
680 37
820 44
935 52

1075 59
1220 68
134 0 74
1485 82
1625 90
1880 105
2135 118
2420 131
2775 155

Length

[m]

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

13

Step 1 2 3 4 5

06

W/m]

Product selection

Self-limiting heating cables (SLC)

SLCs are often used for pipe systems
with many branches, because it's
easier to adjust the cable length to
appropriate pipe length (SLC can
be cut to length provided that the
maximum cable length is observed).

The self-limiting function, that allows
SLC output adjustment based on the
pipe temperature, is a rather useful
feature. However the self-limiting
cable regulation by a thermostat is
recommended due to continuous
use of the SLC, even if heating is not
needed.

When choosing a self-limiting heating
cable it's essential to investigate
whether the heating cable can provide
the required output at the desired
temperature.

How to read the graph

Draw a line from the desired
temperature value (X-axis) and a
calculated heat loss output (Y-axis).

Afterwards find a heating cable with
output values higher (Y-axis) than the
cross point of temperature and output
lines.

Example (see also Step 1)

• Pipe diameter d = 65 mm

• Insulation thickness = 20 mm

• Thermal conductivity value for
insulation λ = 0,04

• Desired temperature tu = +10 °C

• Minimum outside temperature
to = -20 °C

Heat loss Q is calculated by the formula
of Step 1 or from the table on page 11:
Q = 16 W/m.

The choice is for ECiceguard 18 with
linear output of 18 W/m at 10 °C.

40

35

30

Linear output [

25

20

Calculated

heat loss

Q= 16 W/m

15

ECpipeheat 10 V2
ECpipeguard 10
ECpipeguard 25
ECpipeguard 33
ECiceguard 18

14

10

5

0

0102030405

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

Desired temperature

tp= +10 °C

0

Pipe temperature [°C]

Step 1 2 3 4 5

ECf lex 10 T

Output

[W]

Length

[m]

100 10
205 20
290 30
390 40
505 50
600 60
695 70
795 80
920 90

990 100
1220 120
1410 140

Cable length selection

Constant wattage heating cables

All ECflex constant wattage heating
cables are manufactured with specific
lengths. A product to be chosen
should be of the same length or longer
than the entire length of the pipe to be
protected.

If the protected pipe is fitted with
some components such as flanges,
valves, supports, T-branches, or
sprinklers some extra cable length
shall be applied. In this case use the
calculation formula in chapter 4.1.

Important:

It's strictly forbidden to cut a constant
wattage cable. In case of surplus cable
length it should be wound around the
pipe, or for metal pipes only it should
be drawn along the pipe at its end.

Length of cable is connected to the
power supply and it's used to its full
availability. A total length of the cable
has to be used. Reducing cable length
by its cutting is strictly forbidden.

Spiral winding of heating cable around
a pipe gives better heat division and
protection, but requires more space
around the pipe during installation and
thus can be unfeasible in some cases.

For further advice concerning the
cable layout please refer to chapter 5.1
(Installation).

Example:
Pipe length L = 50 m,
Q = 16 W/m (as before).

Heating cable of L

cable

= 52 m

and 935 W output is chosen.

L = 50 m

ECflex 18T

Output

[W]

130 7,3
180 10
270 15
395 22
535 29
615 34

680 37

820 44

935 52
1075 59
1220 68

134 0 74
1485 82

1625 90

1880 105

2135 118
2420 131
2775 155

Length

[m]

Connection point

Steel pipe

Connection point

Steel and plastic pipes

L

= 52 m

cable

L

= 52 m

cable

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

15

Step 1 2 3 4 5

Connection point

Cable length selection

Self-limiting heating cables

Self-limiting heating cables are
available on drums and ready to be
cut to length. The maximum length of
SLC is defined by: a cable type, start-up
temperature and a fuse size.

The length of a self-limiting heating
cable should be enlarged in case of
presence of valves, flanges and alike, in
the same way as for constant wattage
cables (see chapter 4.1 for further
details).

Maximum length of connected
self-limiting heating cables

The maximum length of the combined
(all parts) self-limiting heating cables
can't exceed the value for this cable
included in the table below.

Example:
Pipe length L = 50 m,
Q = 16 W/m.

L = 50 m

230V

The choice is for ECiceguard 18 with 50 m length.

Connection point
230V

L

< L

total

part 1

max

part 2

Total cable length
L

= part 1 + part 2 + part 3 ≤

total

≤ max. allowed length (L

Example: At start up temperature of
+10 °C, 10 A fuse and ECiceguard 18,
L

= 58 m

max cable

Maximum length values for SLCs at different start-up temperatures and fuse sizes

ECpipeguard 10 EC pipeguard 18 ECpipeguard 25 ECpipeguard 33

Start-up

temperature

10A 16A 25A 32A 10A 16A 20A 25A 10A 16A 25A 32A 10A 16A 25A 32A

–20°C 97 156 226 226 35 56 70 87 46 74 116 146 28 45 71 91

–10°C 110 176 226 226 39 63 79 99 52 84 131 146 32 51 81 103

0°C 119 191 226 226 43 70 88 110 58 93 146 14 6 36 58 91 117

+10 °C 119 191 226 226 58 93 116 145 58 93 146 146 42 67 105 120

Maximum cable lengths are defined for
the case when the cable is switched on
being unheated.

max cable

)

In this case its power consumption
will be in the range of 3-7 times of
its nominal value, when reaching its

T-branch points

part 3

Max. length of heating cable at 230 V [m]

Fuse size of C characteristic

Start-up temperature is the possible
min. ambient temperature at which
the SLC is turned on.

operating temperature.

16

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

Step 1 2 3 4 5

Regulator selection

Temperature regulation

Constant wattage as well as self­limiting heating cables require
a thermostat for regulation. The
thermostat ensures maintaining
constant temperature and turning
the heating on while limiting energy
consumption, even for SLCs that are
constantly on and even if it’s not
required.

The thermostat selection depends
on the specific installation. The most
common systems are described
on this page, either with a sensor
placed directly onto the pipe (under
the insulation) or based on the air
temperature sensor.

Systems with a sensor installed
directly on the pipe to be protected is
of the most use.

Temperature regulation using air
sensor

thermostat air temperature sensor

Pipe of different diameters. Installation completed with self-limiting heating cable.

thermostat

on-pipe mounted sensor

thermostat

on-pipe mounted sensor

This system is based on the air sensor
that is installed close to the protected
pipe and that turns on the heating
when the ambient temperature falls
below the set value.

Such set up is primarily used in
cooperation with self-limiting
heating cables.

If the size of the heating elements
exceeds the maximum limit defined
by the thermostat, the connection to
more heating elements needs to be
ensured by means of relays /
contactors. In such installations,
one thermostat can regulate several
heating elements.

Advantage of this system is mostly
visualized in regulating of pipe frost­protection systems, where pipes
have different sizes and insulation
thickness.

thermostat

on-pipe mounted sensor

Pipe of different diameters. Installation completed with constant wattage heating cable.

Temperature regulation using on­pipe sensors

It requires, as shown on the picture,
more thermostats, and is necessary

when:
This type of installation, where the
sensor is placed directly on pipe
under insulation, is more precise and
energy efficient way of regulation
than the air sensor.

• pipes have different sizes or
insulation thicknesses;

• changing temperature conditions,
e.g. pipe from building to outside,
and back to the building, or installed
above or underground;

On-pipe sensor regulation is often
used for systems with many pipes and
branches, with different temperature
settings or conditions.

• mixed pipes delivering stagnant and
moving water;

• pipes delivering any fluid sensitive
to rapid temperature changes

This type of regulation, with on-pipe
sensor, is required when installation
is performed with constant wattage
cables, or on plastic pipes (e.g. PVC, PP,
PE, PE-X).

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

17

aluminum tapes

(pipe dimension Ø 150 mm)

heating cable

(under the tape)

aluminum tape

aluminum tapes

for cable attachment

to the pipe

metal

pipe

~1 m

app. 1,5 m tape

on 1 m of pipe

(pipe dimension Ø 150 mm)

connection box

power connection

entrance gate

Choice of the thermostat also relates
to its temperature range, expected
place of installation (in DIN-rail
box or outside) and any additional
requirements.

Sensor placing

Sensors for pipe frost-protection
systems should be installed in a place
that is the most representative for
the installation, i.e. in the expected
coldest point of this installation (e.g.
on pipe part facing the entrance to
the unheated parking area).

thermostat

sensor

Example:

Pipe length 50 m, a frost protection
installation with a ECiceguard 18
self-limiting cable with DIN-rail
thermostat.
Maintained temperature = +10 °C.

underground garage

Solution is ECtemp 330 (-10...+10 °C),
but ECtemp 330 (+5...+45 °C) can also
be considered.
For more information please refer to
chapter 3 (Products) or to the Danfoss
Product Catalogue.

Step 1 2 3 4 5

Constant wattage and SLC cables

In case of metal pipes the heating
cable can be attached to the pipe
by means of an aluminum tape
placed at intervals of approx. 1 meter.
Subsequently, the total length of the
heating cable needs to be covered
with aluminum tape, securing cables
to the pipe.

In case of the plastic pipes, before
mounting the cable onto the pipe, the
aluminum tape needs to be applied on
the pipe where the heating cable will
be placed. Other part of the installation
steps resembles that of the installation
on metal pipe.

Selection of connection boxes and
accessories for constant wattage
cables

Constant wattage cables are fitted with
connection cables (power connection),
so no additional connection
accessories are needed.

If electric conneciotn point requires, a
connection box can be used.

Accessories selection

(between layers of aluminum tape)

metal

pipe

plastic

pipe

heating cable

~1 m

heating cable

(under the tape)

(between layers of aluminum tape)

installation through the insulation

pipe insulation

aluminum tape

~1 m

1st layer of tape

heating cable

for cable attachment

to the pipe

app. 1,5 m tape

on 1 m of pipe

2nd layer of tape

app. 2,5 m tape

on 1 m of pipe

(pipe dimension Ø 150 mm)

~1 m~1 m

18

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

(part of a heating cable)

connection muff

constant

wattage cable

end muff

(part of a heating cable)

Selection of connection accessories for self-limiting heating cables

Complete set
for 1 branch:

1 x Connection box
3 x Connection to box
1 x Bracket
3 x Through Insulation set

to power supply

230V

connection to box

to power supply

230V

bracket

connection to box

power cable

SLC to SLC connection set

through
insulation set

end element

from connection to box

end element

from connection to box

2. Set of accessories for connection
to power supply (option no. 1):

1 x Connection box
1 x Connection to box
1 x Bracket
1 x Through Insulation set

Connection sets for connection to
box and SLC to SLC contain also end
elements (end muff).

3. Set of accessories for connection
to power supply (option no. 2):

1 x SLC to SLC connection set
1 x Through Insulation set

Connection to power supply
can be done with a heating cable
connected via connection box
(option no. 1), or end up with cold tail
connected with help of option no. 2.

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

Beside shrink tube connection sets,
Danfoss provides a wide range of
easy-fix connection sets for self-limiting
heating cables.

For more details please see
chapter 3 (Products) and the
Danfoss Product Catalogue.

19

5. Installation

5.1. General information

Pipe conditions

Before installing heating cables it is
important to check the pipe for any
signs of damage or leakage.

The pipes should be insulated as this
reduces the heat losses considerably.
This applies for all pipes whether they
are below or above the ground.

The cable should be attached to
the pipe gently, so it does not get
damaged. The entire length of the
cable should be attached to the
pipe with aluminum tape and NOT
plastic tape (e.g. PVC), as it contains
plasticizers.

The cable should be laid in such a
manner to avoid sharp edges on the
pipe. Treading on cables should be
avoided and cables should be treated
carefully at all times.

All pipe trenches should be distinctly
marked to indicate that heating cables
have been installed on/ in them. It
should also be marked with a distinct
warning sign, e.g. “WARNING: 230
VOLT HEATING CABLES“.

Insulated pipes must be marked with a
warning sign placed on the outside of
the insulation material.

Heating cable should not be pulled
with more than 25 kg.

Electrical conditions

The screen of the heating cables must
be earthed in accordance with the
local electricity laws.

The resistance and the insulating
resistance of the heating cable
must be checked before and after
installation. The resistance value must
be as indicated on the label of the
connection box.

The sensor cable can be extended to
any reasonable length using a cable of
min 2 x 0,75 mm².

The cable is attached to the pipe with
strips of aluminum tape placed at
intervals of approx. 1 meter. When the
heating cable has been attached to the
pipe, the entire length of the heating
cable must be covered with lanes
of aluminum tape. This prevents the
heating cable from getting into direct
contact with the insulation material
and ensures a tight fit between the
pipe surface and the heating cable.

Before the heating cable is attached to
the plastic pipe, a full lane of aluminum
tape should be applied to the pipe for
the cable to lie on. This ensures a better
heat distribution to the pipe. Cables
should be attached at the lower part of
the pipe or/and symmetrically around
the pipe.

The connection muff between the
heating cable and the cold tail should
also be fixed with aluminum tape.

The sensor cable is attached to the
pipe in the same way as the heating
cable. The tip at the end of the sensor
should be covered with aluminum
tape and be positioned centrally
between the cable lines and on top of
the pipe, if possible.

The heating cable must not be led
through valves. The heating cable
is relatively stiff that makes the
installation easier.

The cable must be evenly spread and
the crossing of resistive cables must
be strictly avoided.

Pipes are usually insulated with plastic
foam, mineral wool or another kind
of insulation, which can range in
thickness, typically not less than the
pipe diameter.

The insulation should be protected
against damp and moisture that could
damage the insulation and reduce its
efficiency.

Ensure that insulation with bigger
inner diameter is chosen, taking
into account that the pipe diameter
is increased due to heating cable
installation.

Below ground installation

If cables are installed above the
ground in trays, it should be safe
and solid. It should be marked
with a distinct warning sign, e.g.

“WARNING: 230 VOLT HEATING
CABLES“.

When heating cables are installed
below the ground, a plastic tape (red,
yellow etc.) is laid on top of the pipes/
installation to indicate that cables are
placed just below.

For this type of installation it is
necessary to measure the required
pipe run precisely, as the cable cannot
be cut or bent in a loop.

You will need an appropriate assembly
kit to perform cold tail connections
and end muff of heating cables on
drums.

20

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

Installation examples

Installation on Special Flanges and
Pumps

Always observe the minimum
tolerable bending diameter of 25 mm
for resistive cables and 64 mm for
self-limitng cable.

Heating cables on specials, valves
etc. should always be positioned
so that they are easily accessible
and replaceable in connection with
inspection and repair and so that it
will not be necessary to cut them!

You can avoid this problem when
there is sufficient cable wrapped in a
spiral around the specials.

Calculation formulas

Centre-centre (C-C) distance for
cables wrapped in a spiral:

C-C = π  d 

√

1

n2 - 1

Total length of heating cable:
L

[m] = n  L

cable

+ 0,5  (C + FV + 2  T)

pipe

Example of cable mounting on a flange.

Heating cables

Mounting example around a valve and a support flange.

where:
d - Outer pipe diameter;
n - Number of cable lines

(min. 2 for DN125-200).
Integer = straight lines (easier
installation).
Decimal = twisted around pipe;

C-C - Centre distance for twisted cable,

[mm];

Example of mouting a self-limiting cable on pipe
with use of connection box and metal bracket.

Valve

Aluminum tape

L

cable

C - Number of cable connections

FV - Number of flanges/valves

T - Number of T-branches

Support bracket

- Total length of heating cable, [m].
Observe max. length for SLC (see
product sheets);

(0,5 m cable each);

(0,5 m cable each);

(1 m cable each).

Some centre-centre fixing distances when more than 1 meter cable is used on a 1 meter pipe.

Outer pipe

diameter

Inner pipe

diameter (DN)

Inner pipe

diameter

1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8 1,9

Cable length in [m] for each pipe meter

[mm] [mm] [inch] C-C distance [mm]

34 25 1 250 170 140 110 100 86 78 71 66
42 32 1 ¼ 310 210 170 140 130 106 96 88 82
48 40 1 ½ 350 240 190 160 140 121 110 101 93
60 50 2 430 300 240 200 180 151 137 126 117
76 65 2 ½ 520 360 290 240 210 191 174 160 148

89 80 3 630 430 350 290 260 224 203 187 173
102 90 3 ½ 720 490 390 330 290 257 233 214 198
114 100 4 800 560 440 370 330 287 261 239 222
141 125 5 990 680 550 460 400 355 322 296 274
168 150 6 118 0 810 650 550 480 423 384 353 327
219 200 8 1520 1050 840 710 620 551 500 460 426

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

21

Quick solution finder

1

2

3

4

1

2

4

3

5

If you don't need to make a heat loss
calculation, the following tables will
help you quickly to find a correct
product for frost protection of pipes.

How to use the table below?

Based on known inner pipe diameter
(DN) e.g. Ø 65 mm, with 30 mm insula­tion and ∆T of 30K:

Find DN or NPS pipe size in the

According to the table, when looking
up into table on the previous page,
a minimum output to be installed to
protect the pipe from freezing is:
15-25 W/m.

top bar of the table (e.g. DN 65).

Find the temperature difference (∆T),

in the outmost left column (e.g. 30).

Find the insulation thickness in the

Remember to choose preferably the
higher output option, hence
20-25 W/m.

corresponding raw (e.g. 30 mm).

Follow the vertical and horizontal

lines, until they meet.

Table presenting the necessary minimal outputs in [W/m] for straight pipelines (colors and corresponding W/m in table below).

ΔT

[°C]

20

30

40

Specic pipe heat loss q

Insulation

λ = 0,04

[mm]

10

20

30

40

50

10

20

30

40

50

10

20

30

40

50

½”
15

¾”
20

1”

25

Nominal pipe size NPS [inch], DN [mm]

1¼”

32

1½”

40

2”

50

2½”

65

pipe

80

3”

4”

100

5”

125

6”

150

8”

200

Find an appropriate type and number of heating cables to protect the pipe in the following table.

Cable type

Constant wattage
Cable

ECaqua 9T (in-pipe/on pipe)
ECflex 10T
ECflex 18T

ECpipeheat 10 V2

Self-limiting Cable

ECpipeguard 10
ECpipeguard 15
ECpipeguard 25

Example
Quick solution nder

A 12 meter DN50 ( outer Ø 60 mm)
drain pipe with 20 mm insulation
(λ = 0,04 W/m·K) and a drain valve
needs frost protection down to -25 °C
(∆t = +5 °C - (-25 °C) = 30 °C).

The specific pipe heat loss q

pipe

depends on the pipe diameter,
insulation thickness and temperature
difference. The specific pipe heat loss
q

from the calculation table above -

pipe

15-25 W/m (yellow, marked 5).

0 - 6 6 - 10 10 - 15 15 - 25 25 - 50 >50

1
1
1

1
1

Calculation by formula on p. 12.

Exact pipe heat loss:

2π  λ  ∆t

q

=

pipe

D

In

d 60

 1,3 =

2π  0,04  30

60 + 20 + 20

In

Solution:
1 line ECpipeguard 25 W/m with
1 cable connection is chosen.

Specic pipe heat loss q

1
1
1

2
1

1
1 2

1
1

Cable length:
L

= n  L

cable

= 1  12 + 0,5  (1  0,5 + 1 + 2  0) = 13 m.

 1,3 = 19,2

W

As ECtemp 610 controller with a

m

wire sensor is chosen to be attached
between pipe and insulation.

Optionally: 2 parallel lines of ECflex 10T,
with a nearest length of 30 m can be
chosen. Cable should be wrapped
a little, because length is more than
calculated: 2 · 13 m = 26 m.

[W/m]

pipe

2-3

2

Max. 4
Max. 3

2
1 2

+ 0,5  (C + FV + 2  T) =

pipe

More

insulation

required

22

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

5.2 Installation specifics

There are several ways of the cable
attachment to the pipe:

1. One or more cables are led in a
straight line along the side of the
pipe, see fig. 7 and fig. 8.

2. The cable is attached to the pipe in
waves or a spiral, see fig. 9.

3. The cable is installed inside the pipe,
see fig 10. The Special Pipe fitting
(3/4"+1", 10 bar @ 23 °C;
included in ECaqua 9T is required
for heating cable connection to the
pipe, see fig. 11.

The heating cable is mounted
directly on the pipe and secured with
aluminum tape, ensuring optimal
contact (heat transfer) between the
cable and the pipe. The same applies
for wire sensors.

Before the heating cable is attached to
the plastic pipe, a full lane of aluminum
tape should be applied to the pipe for
the cable to lie on.

Fig. 12 shows the recommended ways
to mount the cable lines, depending
on the amount of heating cables to
place on the pipe.

The temperature sensor should be
mounted at 90 degrees from the
heating cable, counting around the
perimeter of the pipe, or at least 5 cm
away from it.

But preferably at the opposite side of
the pipe, compared to placement of
the heating cable.

Insulation

Sensor

Aluminum tape

Heating cable

Fig. 7

Insulation Insulation Pipe

Heating cable

Fig. 9

Sensor

Heating cable

Fig. 8

Insulation

Mounting of heating cables on
pipes with large diameter
(> Ø 100 mm)

In case of larger pipe diameters it's
strongly advised to use more, evenly
divided, lengths of heating cable, with
lower linear output.

Example:
Pipe diameter size = 150 mm, with a
calculated heat loss of Q = 30 W/m, it's
advisable to use 2 lengths of cable with
linear output of 18 W/m, than 1 cable
with output of 33 W/m.

Fig. 10

Pipe diameter

20 – 100 1

125 – 200 2
250 – 400 3
450 – 600 4

Number of parallel running

lines of heating cable

Aluminum tape

Fig. 12. Recommended ways to mount the cable lines.

Fig . 11

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

23

230 V power supply

Example of a solution with use of
self-limiting heating cables

If the maximum length of self- limiting
heating cable exceeds the length
displayed on page 16 (under: choice
of cable length), it needs to be divided
into smaller portions.

Example:

With choice of ECpipeguard 10
(SLPG-10), where the total length of
the pipe is 256 m.

Expected start-up temperature is

-20 °C, desired pipe temperature is
t = +5 °C, and a maximum available
fuse size is: 16 A. From a table on page
16 or proper Data sheet, the maximal
cable length for this SLC is only: 156 m.
It will be necessary to divide the pipe
in 2 independent circuits, with separate
power supply points, as shown on the
picture.

Example of division:
Circuit 1: part 1 + part 2 = 156 m;
Circuit 2: part 3 + part 4 = 100 m.

230 V power supply
(circuit no. 1)

part 1

circuit no. 1

Division in circuits – self-limiting heating cables

part 1 part 3

part 2

230 V power supply

(circuit no. 2)

part 3

part 1

part 4

circuit no. 2

Example of a solution with use of
constant wattage heating cables

In case of the constant wattage
heating cables, the maximal length of
the circuit is limited by the maximum
produced length of the heating cable.

Because the constant heating cables
are not allowed to be cut, at each
T-branch, new cable(s) should be
connected. Each pipe needs to have a
heating cable chosen to accommodate
it's length.

Example:

For frost protection of a metal pipe
shown on the picture, following
solution was chosen.

• Heating cable no. 1:
ECflex 10T, 140 m.

• Heating cable no. 2:
ECflex 10T, 40 m.

• Heating cable no. 3:
ECflex 10T, 40 m.

• Heating cable no. 4:
ECflex 10T, 30 m.

(circuit no. 1)

power supply

(circuit no. 2)

cable no. 2

heating cable no.1

230 V

heating

Division in circuits – constant wattage heating cables

pipe length36 m

heating

cable no. 3

pipe length36 m

pipe length 138 m

230 V
power supply
(circuit no. 3)

power supply

230 V

(circuit no. 4)

heating

cable no. 4

pipe length 28 m

24

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

5.3 Installation Summary

20mm –25

DN25

o

C

+5

o

C

1. Check the pipe system to be heated
and make sure that the pipes are
dry, smooth and tight. Check and
prepare the switch board.

12

9 3

6

4. Twisted lines are attached as shown
for every approx. 1 m pipe with
aluminum tape.
Straight lines must be fitted as
shown at 5 or 7 o’clock.
In-pipe cables are fitted directly into
the pipe and tightened.

2. Draw a plan positioning cable(s),
sensors and thermostat, cable con­nections, cold tail, connection box,
cable paths and switch board.

5. Apply aluminum tape below (manda­tory for plastic pipes) and on top on
the whole length of the cable. Make
sure that the cables do not cross
sharp edges without relief and that
any constant wattage cables do not
cross back on itself.
Attach the cable securely to the
pipe with use of tape and taking
care of preventing appearance of air
pockets.

3. Check the insulation resistance and
Ohm rating of the heating cables.
Compare the Ohm rating with the
nominal written on the cable label.

6. Attach and cover the sensor and the

tip on top of the pipe with alumi­num tape. Extend cold tails / termi­nate cables and place conne- ctions
dry. Mount connection box on the
pipe or close to the pipe and install
the thermostat next to the pipe.

Commissioning

9. Re-check and compare the insulation

resistance and also Ohm rating for
constant wattage cables and earth
resistance.

7. Re-check the insulation resistance
and also Ohm rating for constant
wattage cables. Connect cables to
connection boxes and to the switch
board.

8. After insulation, place safety marking
tape on the insulation jacket or pipe
trenches for every 5 m. In subsurface
installations, a cover ribbon with a
warning sign must be laid 10 cm
above the cables.

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

10. Danfoss thermostat must be
commissioned as prescribed in the
thermostat manual. Recommended
pipe temperature setting is
+3 to +6 °C.

11. Train the end user or daily supervisor

in the operation and maintenance of
the frost protection system.

12. Before every heating season,
check for faults in the switchboard,
thermostat and sensors. Re-check
and compare the insulation
resistance and also Ohm rating for
constant wattage cables and earth
resistance.

25

5.4 Important

Temperature distribution

Aluminum tape and insulation
are important when it comes to
performance and very important in
relation to plastic pipes. A DN50 plastic
pipe (e.g. PP) with 10 W/m at reference
temperature -10°C is shown under 3
different installations.

No alutape overheats constant

wattage cables.

SLC will limit itself and heat insufficiently.

Self-Limiting Cables and standby
savings with thermostat

Always install a thermostat for self­limiting cables >3 m as it

• prolongs the cable lifetime;

• saves the standby energy
consumption;

• leaves e.g. drinking water cold and
fresh, when no heat is needed.

Alutape above and below the cable gives better

performance.

50 mm insulation maintains ∆t = 50 K.

20 mm insulation maintains ∆t = 30 K.

Constant wattage cables with alutape

do not overheat.

26

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

Notes

Application manual · Pipe Frost Protection · VKLUD102 · ©Danfoss

27

6. Cases

THE GAS TURBINE PLANT,
Tereshkovo, Russia

Pipe tracing.

Project size:
ECpipeguard 33 - 170 m;
ECpipeguard 25 - 635 m;
ECtemp 316 (10…+50 °С) - 17 pcs.;
Outdoor sensor IP-44 - 17 pcs.;
Connection kit for SL cables - 160 pcs.;
ECfast (25m) - 36 pcs.;
Alutape 38 mm х 50 m - 1400 m.

SPAR ZENTRALE SALZBURG,
Salzburg, Austria

Frost protection system on water pipes.

Project size:
ECpipeguard 10 - 700 m;
Centrally placed regulators - 25 pcs.

VGHWC102 © Copyright Danfoss | Feb 16, 2021