Danfoss Cold Store Protection Systems Application guide

Cold Store Protection Systems

Cold Store
Protection Systems

Application manual

Intelligent solutions
with lasting effect

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Index

Let DEVI do the work

General information 4

1. Frost heave prevention system 5

2. Protection against
condensation on floors 13

3. Freeze protection of
doors and gates 16

4. Frost protection of
pipes in cold stores 19

5. Frost protection of
drain lines of cooling equipment 23

6. General installation guide 24

7. Case story 28

DEVI - an abbreviation of Dansk El-Varme Industri - was established in
Copenhagen, Denmark, in 1942. As from January 1st 2003 DEVI has become
a part of the Danfoss Group - Denmark's largest industrial Group. Danfoss
is one of the world's leading companies within heating, cooling and air­conditioning. The Danfoss Group has more than 23.000 employees and
serves customers in more than 100 countries.

DEVI 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.

Cold stores, Ice stadiums and alike

This design guide presents DEVI’s recommendations for design and
installation of frost heave prevention systems and frost protection for
cold room doors, drain lines, and fire protection sprinklers and pipes. It
provides guidance for a heating cable layout, electrical data and system
configurations.

Following DEVI’s recommendations will ensure energy efficient, reliable and
maintenance free solution for constant wattage heating cables with 20 year
warranty.

Our quality management
system
and compliances

ISO 9001 TS 16949

ISO 14001 PED

Along with full compliance with EU

directives and product approvals

General
information

In cold stores, ice stadiums, etc. the
temperature is always within the
range of –20 and –30 °C, however
cold leak occurs even if the floor
is insulated properly. This means
that materials which are in contact
with the soil, such as foundation
and floor areas, will absorb the cold
and let the ground freeze. Water,
contained in the soil, will change
volume when turning into ice and
can cause substantial damage due
to frost erosion.

Furthermore, in areas where very
cold dry air meets warm moist
air, the moisture contained in the
warm air flow may settle on the
cold surface and turn into ice. Ice
conduces unwanted freezing of
elements such as cold store doors/
gates or door frames and can cause:
damage to the door structure,
weather stripping, disabling closing
the door tightly and leading to
increased energy consumption, etc.
Another problem, that occurs in a
drainage system of refrigeration
equipment, is condensation
freezing and inability of free water
flow.

DEVI offers reliable and energy
efficient cable heating systems to
prevent frost heave and ensure
frost protection of doors drain
lines and firefighting piping. DEVI
has supplied various range of such
systems to 5 continents over many
years.

Benefits

• Eliminate risk of foundation damage – ice buildup

in the foundation, which can result in problems
such as: uncontrolled movement or elevation of
the building foundation causing damage to the
construction. DEVI prevents frost heaving damage
in commercial freezers & ice stadiums by eliminating
the possibility of such ice buildup.

• Investment safety – reduces the possibility of cold
storage stock loss or destruction of the building due
to the damaged foundation.

• Reduced energy loss - smooth operation of doors,
protects the construction and prevents energy loss
through untightly closed doors.

• Safety of working environment - prevents slippery
floors and ensures frost protection of firefighting
pipes and sprinklers.

• Power saving solution – DEVI uses Advanced
Controls to ensure power saving by: minimizing
running time of the system, while maintaining the
appropriate foundation temperature to prevent its
freezing.

• Space saving – as compared to alternative
solutions, DEVI system is less complicated, easier for
planning & installation and requires no extra space.

• Lower initial costs – competitive solution with
over 50% lower cost of the system, comparing to
Pumped Fluid solution (Glycol) in pipes built into
the foundation.

• No Environmental Concerns – DEVI electric
heating systems do not pose any environmental
hazards, e.g. glycol leak into the soil. DEVI systems
use electric heating cables instead of glycol-water
mixture.

• Lowest ownership costs - 20 years of full warranty
from Danfoss Group and 50 years of expected
lifetime for all DEVI serial resistive heating cables.

4 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

1. Frost heave prevention system

1.2. System Description

The main object of heating, in the
Frost Heave Prevention System,
is to provide frost protection of
foundation in premises where
temperature is constantly
maintained below zero (cold
storages, ice stadiums, etc.).

Installation of an indoor frost
protection system is required
and electrical heating cables
embedded in concrete is a
solution to prevent frost heaving.
Frost heave can cause floor slab
cracking, damage to support
structures and foundations. In
such cases underfloor heating is
needed in order to avoid freezing
or other related problems and
prevent destruction of foundation
structures.

Frost Heaving

As the soil temperature under
a freezer drops below zero,
the moisture contained in the
soil freezes up and expands
significantly.

This ice formation results in
floor cracking and its change of
elevation or “heaving”.

Ice formation can lift up columns,
push over foundation walls
and rip open roofs. Almost all
components of the cold store can
be repaired, whilst the major part
of space is still used for storage,
but this doesn’t apply to the floor.

The problem cannot be solved by
insulation alone.

The heating cable in this case
is located below the main floor
insulation of the cold storage,
typically in the sand backfill or in
concrete screed.

For safety reasons: two identical
parallel heating systems should be
installed (main and reserve).

5Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

1.2. Products

Heating cables

To prevent ground freezing the
heating system may include the
following resistive (constant wattage)
heating cables:

DEVIflex™ 6T, DEVIflex™ 10T,
DEVIflex™ 18T;
DEVIbasic™ 10S, DEVIbasic™ 20S.

DEVI resistive heating cables allow
safe, efficient and economical cold
store installation.

Note. The number at the end of the
cable’s name refers to its specific
output in W/m, at voltage of 230 V
or 400 V. Letter “T” means twin
conductor cable (Twin), letter ”S” –
single-conductor cable (Single).

DEVIflex™ is a twin conductor heating
cable for installation in concrete
floors, pipe heating etc. The cable
complies with IEC 60800:2009 class
M2, and is designed for applications
with the high risk of mechanical
damage. It is supplied in readymade
sets with 2,3 m cold lead (supply
cable), sealed joints and end muff.

Cable diameter is Ø 6,9 mm.

The cable is available for 230 V power
supply.

Cables of 6, 10 or 18 W/m (230 V)
linear output are available.

Available cable length:
DEVIflex™ 6T: 30 - 200 m;
DEVIflex™ 10T: 2 - 210 m;
DEVIflex™ 18T: 7 - 170 m.

DEVIbasic™ is a single conductor
heating cable complying with
IEC 60800:1992 and intended for
installation in concrete floors, for
pipe heating etc. It is supplied in
readymade sets with 2x3 m cold
leads and sealed connection muffs.

Cable diameter is Ø 5,5 mm.

DEVIbasic™ 20S is available for 230 V
and 400 V power supply voltage.

To decrease linear output (W/m) the
400 V cable can be connected to 230 V
means – in this case the cable linear
output is 6,6 W/m.

Available cable length:
DEVIbasic™ 10S, 230 V: 21 - 407 m;
DEVIbasic™ 20S, 400 V: 56 - 229 m.

Fixing

In case of heating cables application,
it is recommended to use fitting
bands to fix the cable to the floor,
e.g. DEVIfast™ metal galvanized
fitting band. It should be attached
to the floor (e.g. nailed down) in
parallel lines usually at intervals of
100 cm or using one meter of fitting

DEVIflex™ DEVIbasic™

band per each square meter of cable
installation. The same applies to
DEVIclip™ C-C and Montagestege™
plastic bands.

For quick cable fixing to reinforced
mesh DEVIclip™ Twist plastic fixing is
recommended.

For cable fixing to metal columns etc.
Alutape adhesive aluminum tape is
recommended.

6 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

Thermostats

For control of Frost Heave Prevention
System the DEVIreg™ 330 (-10…+10 °C)
thermostat with DIN rail attachement
is recommended. Additionally a wall
mounted DEVIreg™ 610, IP44 can be
used.

All thermostats are equipped with
wire temperature sensors –
NTC 15 kOhm @ 25 °C with 3 meter
long cable.

DEVIreg™ 330 DE VIreg™ 610

To provide correct temperature
measuring the sensor cable should
be of e.g. 10 m, to measure the
temperature in the heated area
(depends on the local conditions). 10
m long sensor is available, but needs
to be ordered separately.

Note! For safety reasons: installations
in cold storages should contain
two independent circuits (main
and reserve) controlled by separate
thermostats.

Products - general overview of Frost Heave Prevention Systems

Product Options Description

DEVIflex™
Resistive heating cable

DEVIbasic™
Resistive heating cable

DEVIbasic™
Resistive heating cable

Assembly kits

DEVIreg™ thermostat DEVIreg™ 330 (-10…+10 °C) -10…+10 °C, 16 A, IP20, DIN rail

DEVIreg™ thermostat DEVIreg™ 610

Temperature sensor 10 m, PVC

Temperature sensor 40 m, silicone covered

Fixing

Fixing DEVIclip™ Twist

Fixing Alutape

DEVIflex™ 6T, 230 V;
DEVIflex™ 10T, 230 V

DEVIbasic™10S, 230 V;
DEVIbasic™20S, 400 V

DEVIbasic™ on drum,
0,0134 - 34,1 Ohm/m

DEVIcrimp™ assembly kit
DEVIcrimp™ CS2A/CS2B

DEVIfast™ Metal
DEVIclip™ C-C
Montagestege™ 6 mm
Montagestege™ 8 mm

Twin conductor, 100% screen.
6, 10 W/m (230 V).
DIN IEC 60800:2009 M2

Single conductor, wire screen.
10 W/m (230 V), 20 W/m (230 V/400 V).
DIN IEC 60800:1992 M2

Single conductor, wire screen.
Max. 20 W/m; max. 400 V.
DIN IEC 60800:1992 M2

For single conductor cable.
For twin conductor cable

-30…+50 °C, 10 A, IP44,
on wall/pipe installation

Wire sensor, Ø 8 mm, IP65,
NTC 15 kOhm @25 °C

Wire sensor, Ø 5 mm, IP67,
NTC 15 kOhm @25 °C

25 m pack; galvanized metal, fixings every 2,5 cm.
10 x 1 m; plastic, fixes cable Ø every 1 cm.
1 m; plastic, fixes cable Ø 5,6-6,5 mm every 2,5 cm.
1 m; plastic, fixes cable Ø 6,6-8 mm every 2,5 cm

Bag with 1000 pcs.;
Ø 17 mm; fixing cable to reinforced mesh

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

For details please refer to the DEVI Catalogue.

7Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

1.3. System design

The heating cable for the Frost Heave
Prevention System is located under
the main floor insulation of the
cooling facility, typically into sand
backfill or concrete screed (fig. 1 and
fig. 2).

Heating cable should be placed
under the insulation layer of the
floor to offer frost protection. Cables
should be placed directly on top of
the hardened concrete only, as an
option can also be separated from
the floor surface with the damp
proof membrane. The cables should
be installed at least 5 cm below the
insulation. The floor construction
must comply with local norms and
regulations.

Installed output

Under normal conditions calculated
values of heat loss aren’t very high,
e.g. 3-8 W/m² only. However it is
recommended to use 15-30 W/m²
as a standard value or at least 15 W/m²
for frost protection installations. In
any case an output value should
be calculated and correspond to
downward heat loss.

The foundation cooling rate
depends on:

• the rate of heat/cold emission
through the floor;

• soil/ground temperature;

• interior temperature of the cold
room or surface temperature of ice
stadiums etc.

Floor in cold store Floor in cold store

Reinforced concrete Reinforced concrete

Thermal insulation Thermal insulation

Concrete

Concrete

DEVIfast™ fitting

Sand backfill

Sand backfill

Reinforced mesh

Ground Ground

Fig. 1 – Heating cable in in the concrete screed Fig. 2 – Heating cable in the sand backfill

To estimate the required power
density in [W/m²] of the freeze
protection system, the thermal

Heating system output can be
determined from the following

formula:
resistance of multilayer floor
construction should be calculated.

P = Δt · U · 1,3 [W/m²],
While comparing actual values of all
layers the thermal resistance of each
layer, except the insulation layer,
should be neglected.

where

Δt – the temperature difference

between ground/soil and cold store

interior [°C];

U – the floor heat transfer factor,

typically for insulation only [W/m²·°C];

1,3 – safety factor.

For insulation U value can be

determined as follows:

U = λ/δ = (thermal conductivity

coefficient [W/m·K]) / (thickness [m])

Calculation example

A cold store has the following
parameters:

Cold store temperature: -25 °C.

Ground temperature: +5 °C.

Insulation: 0,2 m thick,
λ = 0,04 W/m·°C.

8 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

The U-value of the insulation:
U = 0,04 / 0,2 = 0,2 W/(m²·°C).

Δt = +5 °C - (-25 °C) = 30 °C.

Calculation of heating system output
per square meter:

P = 30 °C · 0,2 W/(m²·°C) · 1,3 =
= 6 W/m² · 1,3 = 7,8 W/m².

Output calculation is 7,8 W/m², but as

per recommendations, the installed

minimum should be 15 W/m²!

For example, three lines of DEVIflex™ 6T

per m² provide 18 W/m² output and

ensure cold store protection against

frost heaving.

C-C distance

There must not be any subzero
temperature gaps between the
heating cable lines! Otherwise it will
not prevent frost heave!

The temperature distribution in
geometry of cold store floor has to be
evaluated. The result depends on a
number of parameters, the main are
the following:

• thermal conductivity of the
ground;

• linear output of the heating cable;

• C-C distance.

The thermal conductivity of the
soil may vary significantly during
operation, hence in practice following
simplification rule is often used:

to ensure even heat distribution
with no cold gaps the maximum
central-central distance (C-C
distance) between the heating
cables should not exceed 50
cm (fig. 3). In other words, an
installation of minimum 2 meter
heating cable per m², is necessary.

C-C ≤ 50 cm

Fig. 3 – Heat/cold distribution and max C-C without cold gaps

It's very strongly advisable to always
place a second supplementary cable
loop with the same C-C distance.

For installations with max. C-C
distance of 50 cm power output
per 1m² for some cable types is the
following:

DEVIflex™ 6T – 12 W/m²;
DEVIflex™ 10T – 20 W/m²;
DEVIbasic™ 20S, 400 V connected to
230 V – 19,8 W/m².

Recommendations: the preferred
C-C distance between cable lines
is 33 cm. It allows implementation
of a simple rule for cable length
calculation – 3 m of cable per 1 m².

For example three lines of DEVIflex™
6T per 1 m² provides 18 W/m² (230 V)
output. It is applicable for almost all
types of cold stores, ice stadiums etc.

Minimum requirement: 10 W/m
cable should be installed with a C-C
distance of maximum 50 cm.

Safety

For safety reasons two identical
heating systems should be installed
in parallel – the main and the reserve
one.

Elements for such system are
following:

• two identical parallel circuits of
heating cable (main and reserve);

• two identical thermostats with
temperature sensors for each
cable;

• alarm signals in case of reserve
cables operation – light and
acoustic alarm;

• two separate power supply lines;

• separate fuses, RCD relays,
contactors, etc.

Please note that the reserve cable
system is obligatory for this type
of installations. Reserve cables are
usually mounted in parallel to the
main cable with a distance of
2,5-5 cm, to the primary system.

2,5-5 cm

Main cable

Reserve cable

The C-C distance is determined as a
median line between the main and
reserved cable, see fig. 4.

Note! One thermostat per heating
cable should be installed.

C-C C-CC-C

Fig. 4 – Main and reserve heating cables

9Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

Control

The most commonly used thermostat
for Frost Heave Prevention System is
DEVIreg™ 330 (-10…+10 °C) with DIN
rail attachment.

Two identical thermostats, with
separate temperature sensors, should
be used.

The thermostat which controls the main
circuit should be set to a temperature of
+5 °C. It provides adequate protection
against the ground freezing.

The thermostat which controls the
reserve circuit should be set to a
temperature +3 °C. Additionally it
should be connected to an alarm
system (acoustic and light).

In case of failure of the main heating
circuit the reserve circuit, with lower
temperature settings, is switched ON
and the alarm system is activated.

Main thermostat Reserve thermostat +

+5 °C +3 °C

Fig. 5 – Main and reserve thermostats with settings

Alternatively current flow control
devices can be recommended for use.
This is required for each main and
reserve heating cables.

Alarm lamp & bell*

Flow control devices should be
connected to special control system
ensuring alarm activation if any cable
fails to heat (no current flow).

Special heated zones

For large rooms, the system should
be divided into zones, ensuring
protection by separate heating
circuits. An individual thermostat is
required for control of each zone.

Columns, concrete walls, etc. inside
a cold store call for special attention.
They can cause cold bridges with
downward cold flows, that may
provoke soil freezing around its
base. In any case, we recommend
arrangement of thermal insulation
over the entire height of the columns.
However, extra heating of the column
base is required, either by the same
heating cable installed in the floor or
an individual one.

Ensure proper thermal contact
between the heating cable and
a column. For concrete columns
it is recommended to cover the
cable with a plaster layer, tile glue,
concrete, etc. For metal columns the
heating cable should be attached to
the surface by adhesive aluminum
tape along the entire length.

In order to calculate the required
heating power thermal insulation
parameters and the column design
data are needed. Heat/cold loss
calculation is the same as described
above in "Installed output".

Extra heating along the outside
wall perimeter of the cold room is
recommended – directly nearby
outside walls.

The floor surface along the perimeter
gets in contact with the ground
outside the facility and during winter
period freezing is possible.
Two additional cable lines with
C-C = 5…7,5 cm are recommended in
such cases.

10 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

Cables on drum

A single conductor DEVIbasic™ is
available on drums. In this case
heating cables can be selected
with any linear output (W/m), not
exceeding 20 W/m. As a result the
length of a separate heating cable
can be very long. Long cables allow
reducing amount of heating zones.

As an additional advantage the
accurate length of heating cables can
be ensured during installation. But it
should be noted that cold tail joints
and terminal connections should be
performed by qualified personnel.
Ensure that proper type and size of
cold tail and joints are selected.

1.4. Installation

As mentioned above (ref. to 1.3) there
are two variants of cable installation:

• in the concrete screed of base floor
structure;

• in the sand backfill below all
building structures.

For example the most widely used
DEVIbasic™ cable on drums with
0,0134 Ohm/m min. resistance and
5 W/m linear output can be approx.
850 m for 230 V and approx. 1400 m
for 400 V.

You should use appropriate
DEVIcrimp™ assembly kits to perform
cold tail connection and terminations
of heating cables. For a single
conductor DEVIbasic™ it can be used
DEVIcrimp™ assembly kit (product
number: 18055442) and for twin­conductor cables (DEVIflex™ etc.)
– DEVIcrimp™ assembly/repair kit
2-cond. CS2A/CS2B (product number:

18055350).

The cable should be spread evenly
on the floor of the cold store and
securely attached, usually by means
of DEVIfast™ fitting band. Installation
in the concrete screed is virtually the
same as installation of the underfloor
heating. When cable is mounted in
sandy backfill it is important to fix it
securely to a metal or plastic mesh.

For details concerning Ohm/m values
please refer to the DEVI Catalogue.

For calculation of cable on drums the
following formula can be used:

L = U / √(p·r),

where
L – length of heating cable (m);
U – supply voltage (V);
p – linear output (W/m);
r – linear resistance (Ohm/m).

As an example the Frost Heave
Prevention System with 3 heating
zones and with 3 pairs of heating
cables is shown in fig. 6.

Cable muffs Two floor sensors in conduit tube Two heating cables: main and reserve

< 1 m

DEVIfast™Cable channel

Zone 1

Zone 2

Zone 3

Fig. 6 – Heating system with 3 zones. There are pairs of heating cables and sensors (main and reserve)

11Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

Temperature sensor

The temperature sensor (wire
sensor) should be installed in
a conduit pipe of 14-20 mm
diameter. The pipe should provide
free access to the wire sensor
for replacement (remove-insert)
through a hole in the mounting
box. Large bending radius is
recommended where the pipe
is bent between the floor and
the wall. The pipe end should be
sealed to avoid concrete from
entering.

The pipe/sensor must be
positioned in the center at an open
end of a cable loop and usually at
the same level or a little above.

Some examples with heating cables installed on the base of cold store floors.

For sensors to measure correct
temperature, avoid placement of
sensor(s) near walls where extra
heating from outside is possible.
The recommended distance of
the sensor is approx. 5-10 m from
the wall. A wire sensor with a
dedicated long connecting cable,
e.g. 10 m, is required.

The sensor cable can be extended
to any reasonable length
(e.g. 100 m) using a cable of
min. 2 x 0,75 mm². It is important
to place the sensor (sensor tube),
in the middle, between the heating
cables.

As an option the sensor can be
placed in the center of a heated
zone. Considering that the
heated zone center is located far
from the service access point.
It is recommended to install
the sensor by means of U-tube
accompanied by U-shaped wire
hawser/rope. This helps to avoid
possible problems with the sensor
replacement.

12 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

2. Protection against condensation on floors

2.1 Systems description

Cold rooms suffer from one more
problem related to floor areas
nearby doors and doorframes –
slippery floor. In the areas where
very cold dry air meets warm moist
air, the moisture from the warm air
flow may settle on the cold surface
and turn into ice. To prevent this,
an anti-slippery heating system
should be installed.

Floor heating systems are
necessary for anti-slippery and frost
protection. Electrical heating cable,
embedded in concrete, is a solution
for small floor areas nearby doors.

In doorways between cold
stores and heated rooms
condensed water may form on
the floor: opening and closing
of doors causes the constant
shifts between cold and warm
air. This can result in dangerous
and operation-limiting ice
formations on the floor or
in the door opening and
therefore, the floor in these
areas must be heated.

As an extra comfort, it will also
limit the flow of cold air to the
heated area.

2.2 Products

Heating cables

For a heating system to prevent
freezing of the ground following
resistive heating cables and mats
can be used:

DEVIflex™ 18T (230 V);
DEVIbasic™ 20S (230 V and 400 V);
DEVIsnow™ 300T (230 V and 400 V).

Note. The number at the end of the
cable’s or mat's name refers to its
specific output – W/m or W/m², at
voltage of 230 V or 400 V. Letter “T”
means twin conductor cable/mat
(Twin), letter ”S” – single-conductor
cable (Single).

Fixing

For cable fixing to the floor
basement it is typically used
DEVIfast™ metal galvanized fitting
band -with fixing elements at
intervals of 2,5 cm. It is attached
to the floor (nailed) in parallel
lines usually at 25 cm intervals or 4
meter fitting band per each square
meter of a cable installation.
The same applies to DEVIclip™ C-C
and Montagestege™ plastic bands.

For quick cable lines fixing to a
reinforced mesh it is recommended
to use DEVIclip™ Twist plastic fixing
element.

Thermostats

To control floor heating
system DEVIreg™ 330 (5…45
°C) thermostat with DIN rail
attachment is recommended as a
standard solution.

Wall mounted DEVIreg™ 610 (IP44),
can also be used.
All thermostats are equipped with
wire temperature sensors as a set –
NTC 15 kOhm @ 25 °C, 3 m.

Find thermostat pictures in
chapter 1.2.

13Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

Products - general overview of Protection against condensation on floor

Product Options Description

DEVIflex™
Resistive heating cable

DEVIbasic™
Resistive heating cable

DEVIsnow™
Resistive heating mat

DEVIreg™ thermostat DEVIreg™ 330 (5…45 °C) 5…45 °C, 16 A, IP20, DIN rail mounting

DEVIreg™ thermostat DEVIreg™ 610

Fixing

Fixing DEVIclip™ Twist

DEVIflex™ 18T, 230 V

DEVIbasic™20S, 230 V
DEVIbasic™20S, 400 V

Resistive heating mat DEVIsnow™
DEVIsnow™ 300T, 230 V
DEVIsnow™ 300T, 400 V

DEVIfast™ Metal
DEVIclip™ C-C
Montagestege™ 6 mm
Montagestege™ 8 mm

Twin conductor, 100% screen.
18 W/m (230 V).
DIN IEC 60800:2009 M2

Single conductor, wire screen.
20 W/m (230 V/400 V)
DIN IEC 60800:1992 d

Twin conductor, 100% screen, UV stabilized.
300 W/m² (230 V/400 V). Width: 0,5, 0,75, 1 m.
DIN IEC 60800:2009 M2

-30…+50 °C, 10 A, IP44,
wall/pipe installation

25 m pack; galvanized metal, fixings every 2,5 cm.
10 x 1 m; plastic, fixes cable Ø every 1 cm.
1 m; plastic, fixes cable Ø 5,6-6,5 mm every 2,5 cm.
1 m; plastic, fixes cable Ø 6,6-8 mm every 2,5 cm

Bag with 1000 pcs.;
Ø 17 mm; fixing cable to reinforced mesh

For details please refer to the DEVI Catalogue.

2.3 System design

The heating cable and mats for
protection against condensation
around doorways are located
typically in concrete screed just
below the floor surface.

Heating cables/mats must be
planned at both sides of the doorway,
but they should not be laid across
expansion joints. This means that
it is better to use separate heating
elements for installation inside and
outside doorways.

Installed output

The installed output for condensation
protection of floors is normally
250-300 W/m² per each side of the
doorway.

C-C distance

For standard heating cables the C-C
distance should be 7,5 cm, which
ensures output of 240 W/m² for
DEVIflex™ 18T and 265 W/m² for
DEVIbasic™ 20S.

Note. C-C = 7,5 cm is relevant to
a cable length as follows: 1 m² of
heated area requires 13 m cable.

The system should cover an area of
min. 2 meters from each side of the
door.

Cable and mats are usually installed
in the same way as for ordinary
concrete floors.

Control

Thermostats with floor temperature
sensors should be used.

The temperature of the thermostat
must be set to ensure that the floor
surface is kept frost-free, so at least
at +5 °C. However to ensure water
drying up from the floor surface the
temperature can be much higher
and should be determined by an
experiment.

≥ 2 m

≥ 2 m

The most commonly used thermostat
for Protection against condensation
on doors floor is DEVIreg™ 330
(-10…+10 °C) with DIN rail
attachment. Also it can be used a
wall/pipe mounted DEVIreg™ 610.

As an option DEVIreg™ 130 is
the only Comfort Floor Heating
thermostat that can be used for
protection against condensation on
floor. Ensure the correct thermostat
location, taking into account that its
protection class is IP20.

14 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

2.4 Installation

Cables and mats installation in the
concrete screed is almost the same as
installation of the underfloor heating.

The cable is mounted in the floor
basement and usually attached
by DEVIfast™ metal fitting band.
Recommended distance between
fitting bands is 25 cm. In case of
cable fixing to a metal mesh ensure
that it is attached securely. The
heating cable should be covered by
5 cm of concrete.

Temperature sensors (wire sensor)
should be installed in a conduit
pipe of 14-20 mm diameter. The
pipe should provide free access
to wire sensors for replacement
(remove-insert) through a hole in
the mounting box. The pipe end
should be sealed to avoid concrete
from entering. The minimum
bending radius is 6 cm.

The pipe/sensor must be
positioned in the center at an open
end of a cable loop and usually at
the same level.

The temperature of the thermostat
must be set to ensure that the floor
surface is kept frost-free (min. +5 °C),
evenly over the whole heated surface.

DEVIclip™ Twist

For use on reinforcement mesh.

DEVIfast™

For keeping exact C-C distance
(2,5 cm steps) on even surfaces.

Cable ties

For use on reinforcement mesh.
Do NOT fix the loop.
The cable must be able to move.

15Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

3. Freeze protection of doors and gates

3.1 Systems description

In the areas where very cold dry air
meets warm and moist air, moisture
from the warm air flow may settle on
the cold surface and turn into ice. In
cold stores there is permanent frost
influence, which means that the door
can easily freeze. Apart from the
obvious damage to the door sealing
strip, frozen weather stripping may
also prevent the door from shutting
tightly leading also to increased en­ergy consumption in the cold room
due to big temperature differences.

Typically frost protection systems are
used for: sliding doors, swing doors,
gates in car washes, doors in cold
stores, roller edges in water treat­ment plants etc.

For sliding doors and swing
doors, etc. the frost can also be
a problem for slide bars.

This does not apply only to
cold stores but also to gates
and doors of car washes, etc.
where there is a potential frost
risk during winter.

In this case the problem can
also be solved by means of
heating cables.

3.2 Products

Heating cables

For outside doorframes and doors,
any cable with linear output of 15-20
W/m is applicable. The cable should
be fixed to the doorframe by means
of adhesive aluminum tape or em­bedded in concrete connected to the
doorframe.
The following resistive heating cables
are recommended:
DEVIflex™ 18T (230 V);
DEVIbasic™ 20S (230 V);
DEVIhightemp™ (on drum).

For installation inside door frame it is
usually used a single conductor DEVI­hightemp™ high temperature silicone
heating cable. This is because, in most
cases, it is not possible to glue a cable
inside the frame construction and
the cable can be overheated. High
temperature cable is a good solution
for this type if installations.

The product list for DEVIhightemp™
silicone cables includes cables on
drums with different Ohm/m values.
The actual resistance should be calcu­lated using a formula in chapter 1.3.
Please remember that connection of
silicon cold tails should be performed
by means of special high temperature
connections muff.

Fixing

Attachment of cable lines to metal
doors and doorframes is usually
performed by adhesive aluminum
tape, e.g. Alutape.

For cable fixing to concrete the
most commonly used fitting band
is DEVIfast™ - a metal band with
fixing elements at 2,5 cm intervals.
DEVIfast™ can be attached to
concrete by means of nails, screws,
glue etc. at approx. 25 cm intervals.

Thermostats

Such applications usually don’t
require a thermostat, but for limitting
of running cost, it is advisable to
install one.

Like option for high output heating
systems can be used DIN rail
thermostat DEVIreg™ 330 (5…45 °C)
or wall mounted DEVIreg™ 610.

Products - general overview of

Freeze protection doors and gates

Product Options Description

DEVIflex™
Resistive heating cable

DEVIbasic™
Resistive heating cable

DEVIhightemp™
Silicone resistive heating cable

Fixing DEVIfast™ Metal

Fixing Alutape

For details please refer to the DEVI Catalogue.

DEVIflex™ 18T, 230 V

DEVIbasic™20S, 230 V

DEVIhightemp™
0, 82…74 Ohm/m

Twin conductor, 100% screen.
18 W/m (230 V).
DIN IEC 60800:2009 M2

Single conductor, wire screen.
20 W/m (230 V)
DIN IEC 60800:1992 M2

Single conductor, no screen.
Max. 40 W/m, max. 170 °C.

5…45 °C, 16 A, IP20,
DIN rail

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

16 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

3.3 System design

In case of cable installation inside
doorframes etc. it is usually
impossible to secure the cable and it
is just mounted (free henging) inside
the doorframe. Moreover there are
some areas with small bending radius
along the cable route. Therefore
the only solution is to install
DEVIhightemp™ silicon heating cable.

For outside doorframes and along
the door/gate perimeter, heating
cables used for floor heating, are
installed.

In case of cable installation on
outside doorframes, it should be
fixed to the frame by adhesive
aluminum tape or embedded in
concrete, in the close vicinity to the
frame, to ensure appropriate heat
transferring and prevent the cable

overheating.

In case of installation inside doors/
gates it is recommended to fix the
cable by adhesive aluminum tape.
Special flexible connection for power
supply is required due to doors/
frames rotation and movement.

Installation on door seal around
gates and doors, etc is performed
by attaching a silicone cable with
aluminum tape at the back of door
seal before it is secured.

For the purpose of frost protection
of floor slide bars the cable must be
placed in concrete directly under the
slide bar. It is important that the cable
is placed in such a manner to prevent
its damage during the bar mounting
and movement.

Installed output

The installed output for gates and
doors of cold rooms is typically
15-20 W/m per each door seal.

For swing doors and slide bars of
outside gates, the installed output
must correspond to the output used
for ice and snow melting systems,
e.g. typically 250-350 W/m²
(C-C = 7,5 cm).

The recommended linear output for

C-C distance

For cables installed in concrete (slide
bars, doorframes, etc.) it is common
to use 2 cable lines with C-C distance
of 5 or 7,5 cm.

Virtually the same should apply for
cables installed along the inside
perimeter of doors etc.

PVC and silicon heating cables is 15­20 W/m and max. 40 W/m for silicone
cables.

Control

For limitting of running cost, it is
advisable to install a thermostat.

As an option for high output heating
systems it can be used DEVIreg™
330 thermostat (5…45 °C) with DIN
rail attachment or wall mounted
DEVIreg™ 610.

Safety

For safety reasons, door heating
applications can be powered by low
voltage power supply, e.g. 12 V.

For standard heating cables the
C-C = 7,5 cm provides output of
240 W/m² for DEVIflex™ 18T and
265 W/m² for DEVIbasic™20S .

17Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

Silicon cables on drum

DEVIhightemp™, a single conductor
silicone resistive heating cable, is
available on drums only. In this case
heating cables can be considered of
any linear output (W/m). Cable on
drums can be calculated using the
formula in chapter 1.3.: L = U / √(p·r).

Max. linear otput is 30 W/m.

Length of DEVIhightemp™ cable with
linear output of 20 W/m and power
supply of 230 and 12 V are presented
in the table.

For details please refer to the DEVI
Catalogue.

Example 1

An automatic sliding gate to a cold
room is to be protected against frost.
The door is 4,5 m high and 6 m wide.
Power supply is 230 V.

A silicone cable is attached to
the back of the door seal before
the latter is secured. The required
cable length is 4,5 + 4,5 + 6 = 15 m.
DEVIhightemp™ silicone cable of
appropriate length (the closest value)
and of 8,93 Ohm/m can be chosen
(see table above). For L = 15 m and
r = 8,93 Ohm/m the calculated linear
output is 26,3 W/m (from the formula
in chapter 1.3. p = U² / (L²·r)). This is a
correct W/m value for silicone cable
restrictions with max. 30 W/m.

Cable should be fixed to the door seal
by means of an adhesive aluminum
tape, e.g. Alutape.

DEVIhightemp™

linear resistance 230 V 12 V

74 O hm/m 6 0,3

8,93 Ohm/m 17 0,9

5,00 Ohm/m 23 1,2

3,34 Ohm/m 28 1,5

2,38 Ohm/m 33 1,7

1,13 Ohm /m 48 2,5

0,82 Ohm/m 57 3,0

Length, m

(20 W/m)

Example 2

For an outside sliding gate the floor
slide bar should be frost protected.
The bar is 8 m long and 0,1 m wide.

This gives an area of:
8 m · 0,1 m = 0,8 m²,
where the output, e.g. for DEVIflex™ 18T
cable with C-C = 7,5 cm is approx.
190 W (240 W/m²).
Two lines of DEVIflex™ 18T with approx.
36 W/m sliding bar must be installed.
Therefore, it can be chosen a twin
conductor DEVIflex™ 18T
of 15 m (270 W).

Heating cable should be laid along
the sliding bar in both directions. For
cable fixing it can be used DEVIfast™
fitting band.

Another special feature of the cable
on drums is: the precisely required
length of heating cables that is
required by the current application.
Please note that cold tail connections
and muffs should be performed by
qualified personnel only. Ensure that
proper type of the cold tail cable is
selected – it has to be silicone (high
temperature) cable.

An appropriate assembly kit is
required to perform cold tail
connections. For a single conductor
DEVIhightemp™ cable Joining-kit for
silicone (product number: 86000080)
can be used – with shrink tubes,
2 x 0,5 m silicon cold tails of 1 mm²,
max. 170 °C.

18 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

3.4 Installation

For outside doorframes and along
the door/gate perimeter, it is usual
to use serial resistive heating cables
applied for the floor heating.

In case of cable installation on
outside doorframes it is used two
types of cable fixing:

• by means of adhesive aluminum
tape, right to the frame back;

• by embedding in concrete in the
close vicinity to the doorframe
concrete construction.

In case of cable installation inside
along the door/gate perimeter, it is
recommended to fix the cable by
adhesive aluminum tape.

Special flexible connection for power
supply is required due to doors/
frames rotation and movement.

Installation on weather stripping
around gates and doors, etc. is
performed by attaching a silicone
cable with adhesive aluminum tape
to the weather stripping back before
it is secured.

For the purpose of frost protection
of floor slide bars, the cable must be
placed in concrete directly under the
slide bar. It is important that the cable
is placed in such a manner to prevent
its damage during the bar mounting.

4. Frost protection of pipes in cold stores

4.1 Systems description

Inside cold stores/rooms the negative
temperature is maintained all the time.
Process pipelines are usually installed.
Additionally firefighting pipelines and
sprinklers should be ready for water
supply in cold stores.
Frost protection is typically used for
heating pipelines with liquids inside
as well as fire pipelines and sprinklers.
DEVI pipe heating systems can be
installed both inside and outside the
pipes.

Benefits

• Frost protection of pipes - eliminating costly
repairs and replacement

• Secures constant flow in pipes

• Any installation areas

• No repair costs

19Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

4.2 Products

Heating cables

The following heating cables can be
used for the pipe heating system:

Resistive (constant wattage):
DEVIflex™ 6T, DEVIflex™ 10T, DEVIflex™ 18T;
DEVIbasic™ 10S, DEVIbasic™ 20S.

Self-limiting cables (SLC):
DEVIpipeguard™ 10,
DEVIpipeguard™ 25,
DEVIpipeguard™ 33;
DEVIiceguard™ 18.

Heating cable for installation inside
water pipes:
self-limiting DEVIpipeheat™ 10
and DEVIaqua™ 9T.
This cable is approved for use in
contact with drinking water.

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

Due to the parallel power supply the
self-limiting heating cable can be
shortened or extended anywhere. This
simplifies the planning and installation.

Fixing

Cable lines attaching to metal or plastic
pipes is recommended by means of
Alutape adhesive aluminum tape.

Thermostats

To control a pipe heating system
DEVIreg™ 330 (5…45 °C) thermostat
with DIN rail attachment and pipe or
wall mounted DEVIreg™ 610, IP44 are
recommended.
All thermostats are equipped with wire
temperature sensors in set –
NTC 15 kOhm @ 25 °C, 3 m.

Find the thermostat pictures in
chapter 1.2.

Product overview for Frost Protection of Pipes

Product Options Description

DEVIflex™
Resistive heating cable

DEVIbasic™
Resistive heating cable

DEVIaqua™
Resistive heating cable

DEVIiceguard™
Self-limiting heating cable

DEVIpipeheat™
Self-limiting heating cable inside pipe

Assembly kit DEVIcrimp™ CS2A/CS2B For 2-cond. cable

DEVIreg™ thermostat DEVIreg™ 330 (5…45 °C)

DEVIreg™ thermostat DEVIreg™ 610

Temperature sensor 10 m, PVC

Temperature sensor 40 m, Santropene high temperature

Fixing Alutape

DEVIflex™ 6T, 230 V;
DEVIflex™ 10T, 230 V;
DEVIflex™ 18T, 230 V

DEVIbasic™10S, 230 V;
DEVIbasic™20S, 230 V;
DEVIbasic™20S, 400 V

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

DEVIiceguard™ 18 Readymade, 2-50 m;
DEVIiceguard™ 18, on drum

DEVIpipeheat™ 10 with plug, 2-25 m.
3/4"+1" Pipe fitting (13 bar @ 22 °C)

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

Single conductor, wire screen.
10 W/m (230 V), 20 W/m (230 V/400 V); Ø 5,5 mm.
DIN IEC 60800:1992 M2

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

18 W/m @ 10 °C.
11,8 x 5,8 mm.

10 W/m @ 10 °C, 100% screen.
7,7 mm × 5,3 mm.
Approved for use in drinking water.

5…45 °C, 16 A, IP20,
DIN rail

-30…+50 °C, 10 A, IP44,
wall/pipe installation

Wire sensor, Ø 8 mm, IP65,
NTC 15 kOhm @ 25 °C

Wire sensor, Ø 5 mm, IP67,
NTC 15 kOhm @ 25 °C

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

For details please refer to the DEVI Catalogue.

20 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

4.3 System design

Output of the heating cables installed
on pipe should not be less than the
calculated heat loss from pipe surface
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 insulation thickness is at least
the same as the pipe diameter,

• the temperature of cold store 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 (DEVIflex™ 10T, etc.) is
required. Cable should be laid in a
straight line along the pipe, i.e. the
selected cable length is the same as
the pipe length or the next value in
a row.

Some extra length of the heating
cable is required for valves, joints,
control devices, etc.

For more details on frost protection
of pipes and heat loss calculation
please refer to the DEVI Pipe heating
application. Minimum ambient
temperature to be considered should
be the cold store temperature.

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).

Insulation

Sensor

Aluminium tape

Heating cable

Fig. 7

Insulation Insulation Pipe

Heating cable

Fig. 9

The heating cable is mounted
directly on the pipe and secured with
aluminum tape ensuring optimal
contact (heat transfer) between the

Sensor

Heating cable

Fig. 8

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.

Insulation

cable and the pipe. The same applies
for wire sensors.

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.

Aluminium tape

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 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)
is required for heating cable
connection to the pipe, see
fig. 11.

Fig. 10 Fig. 11

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

21Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

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.

Connection to electricity (power
supply) must be performed by an

4.4 Installation

authorized and qualified electrician
and in accordance with the local
electrical regulations.

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“.

Heating cables for drinking water
pipes must be connected via RCD
relay. It should also be marked with a
distinct warning sign.

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

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

You will need an appropriate
DEVIcrimp™ assembly kit to perform
cold tail connections and end muff
of heating cables on drums. For
instance, DEVIcrimp™ assembly/
repair kit 2-cond. CS2A/CS2B
(product number: 18055350).

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

Besides, the pipes should be
insulated as this reduces the heat loss
from the pipe considerably. This goes
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.

The cable should not be laid on the
sharp edges of the pipe. Treading on
the cables should be avoided and the
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“.

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.

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

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 cable is attached to the pipe with
strips of aluminum tape placed at
intervals of approx. 25-30 cm. 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 box 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 cable must be evenly spread and
the crossing of resistive cables must
be avoided.

22 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

5. Frost protection of drain lines of cooling equipment

5.1 Systems description

Ice leads to unwanted freezing of ele­ments such as drainage of cold store
refrigeration equipment. Condensate
water can freeze up into pipes, water
trays, etc. disabling free water flow ,
and damage the cooling equipment.

5.2 Products

Heating cables

The following self-limiting heating
cables (SLC) can be used for Frost
protection of drain lines:
DEVIpipeguard™ 25,
DEVIpipeguard™ 33;
DEVIiceguard™ 18.

Product overview for Frost protection of drain lines

Product Options Description

DEVIpipeguard™
Self-limiting heating cable

DEVIiceguard™
Self-limiting heating cable

DEVI product choice is: self­limiting heating cables connected
to power/control system of
chilling/refrigerating equipment.

Fixing

Inside pipes the SLC typically is not
fixed.
Fixing cable lines to metal surface
of water trays, etc. is recommended
by adhesive aluminum tape, e.g.
Alutape.

DEVIpipeguard™ 25, on drum
DEVIpipeguard™ 33, on drum

DEVIiceguard™ 18 Readymade, 2-50 m
DEVIiceguard™ 18, on drum

Thermostats

Such applications typically do
not require thermostat. Heating
cables are usually connected to
power/control system of chilling/
refrigerating equipment.

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

18 W/m @ 10 °C.
11,8 x 5,8 mm.

Assembly kit DEVIcrimp™ CS2A/CS2B For 2-cond. cable

Fixing Alutape

For details please refer to the Danfoss Catalogue.

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

5.3 System design

Self-limiting heating cable is usually
used, for this type of application. This
is due to the fact, that heating cables
aren’t operated by thermostat and/
or power/control system of chilling/
refrigerating equipment is used.

SLCs with the output of at least
18 W/m @ 10 °C is recommended.

If any part of self-limiting cable is
subjected to the sun, UV-stable cable

(e.g. DEVIireg™ 18), or UV-stable
shrink tube, shdould be used. If cable
is designed for installation in pipes
for condensate water, the cable
length should not be less than the
total pipe length.

Due to the parallel power supply the
self-limiting heating cable can be
shortened or extended into desired
length. This simplifies the planning
and installation.

If cable is designed for installation in
water trays etc. it should be fixed to
metal surface by adhesive aluminum
tape.

Cold tails for self-limiting cables
must be performed by an authorized
and qualified electrician and in

accordance with the local electrical
regulations.

An appropriate DEVIcrimp™ assembly
kit is needed to perform cold tail con­nections and end muff for heating
cables on drums, e.g. DEVIcrimp™
assembly/repair kit 2-cond. CS2A/
CS2B (18055350).

For more details on frost protection
of pipes please refer to chapter 4 and
the DEVI Pipe heating application.

5.4 Installation

For details on installation please refer
to chapter 4.4 and the DEVI Pipe
heating application.

23Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

6. General installation guide

The installation of heating cables
and thermostats should comply with
general and local regulations. The
cables and the thermostats should
only be connected by an authorized
electrician.

The foundation must be clean and
free of sharp objects.

The cables must never get into
contact with the insulation material
or become enveloped by it in any
way.

The cables must be evenly spread on
the available floor.

The cables must be gently attached
so they are not damaged.

To ensure an accurate and easy
installation of the cables, DEVIfast™
fitting bands can be used.

The concrete around the cables
must not contain sharp stones and
should have a consistency enabling
it to surround the cable completely
without leaving air pockets.

The concrete should be applied very
carefully in order not to damage the
heating cables!

If the floor is built on the ground,
a damp proof membrane is
needed to prevent moisture from
moving upwards and into the floor
construction.

The wire of the floor sensor must be
protected by a plastic pipe.

The sensor must be positioned in
the center at an open end of a cable
loop. Where the pipe is bent between
the floor and the wall, the minimum
bending radius is 6 cm.

The pipe must be sealed at the end to
prevent concrete from entering.

Should the cable become damaged
while being laid out or later during
the building process, it is a great
advantage in the fault finding process
to know the exact positioning of
the connection box between the
heating cable and the cold cable
as well the end of the cable end,
as the cable layout. It is therefore
important to make a sketch showing
the positioning of these things in the
room.

The heating cable and the connection
muff between the heating cable and
the cold cable must both be cast

in concrete. If the cable is pushed
down into the insulation material or
covered by it in any other way, the
surface temperature can become
too high, which might result in cable
defects at worst.

It is not recommended to lay cables
at temperatures below -5 °C.
At low temperatures (below 5 °C)
the cable can become difficult to
handle due to the plastic sheath.
This problem can be overcome by
connecting the cables to power
supply for a short period of time.
For this purpose THE CABLE MUST
BE ROLLED OUT! When the cable has
become flexible again, the electrical
flow should be disconnected.

Heating must not be turned on
before the concrete has fully set.
It takes approximately 30 days for
concrete.
It is important to carefully followed to
the manufacturer’s recommendations
and instructions carefully.

The resistance and insulation values
of the heating cables should always
be measured before and after the
concrete, etc. is applied.

24 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

NotesNotes

25Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

NotesNotes

26 Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

NotesNotes

27Application manual · Cold Store Protection Systems · VGLUB102 · ©DEVI

7. Case story

DEVI has been chosen to protect the biggest cold store built on the Middle East.

The biggest Middle Eastern cold
store belonging to a supermarket in
the popular Arabian chain "Panda",
located in Jeddah, Saudi Arabia,
will be equipped with DEVI. The
construction has been finished by the
end of Q3, 2015.

DEVI electrical heating solutions is
used for the protection of thresholds
and floor of the biggest Middle
Eastern cold store. The total size
of the project is 8000 m2 and total
installed power is approximately 160
kW.

“The constant temperature in average
cold room is even up to -30 °C,
which may impact a building
construction and surroundings,
even though the floor is well
insulated. – Serhan Ozten Ismail
from Danfoss Dubai said. – Without
an additional protection such cold
can cause serious damages due to
frost erosion. The best solution to
avoid them is installation of electrical
heating cables during a cold room
construction. We are glad that DEVI,
as the reliable partner, was chosen
for the biggest Middle Eastern cold
sore. It has been the biggest cold
store project for us so far, but we
strongly believe that DEVI meets all
expectations and demands required
by such huge constructions.”

0809XXXX & VGLUB102

The project was completed by YMCO
at the end of September 2015 and,
to meet all needs of such huge
cold store construction, following
products were chosen:

DEVIbasic™ 192 m – 14 pcs;
DEVIbasic™ 229 m – 73 pcs;
DEVIsnow™ 63 m – 13 pcs ;
DEVIsnow ™ 140 m – 18 pcs ;
DEVIfast™ – 982 pcs;
DEVIreg™ 330 (-10...+10 °C) – 30 pcs.

Intelligent solutions
with lasting effect

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