roof application special

VärmeKabelTeknik Velox Frost protection of roofs

From

Velox Frost protection of roofs VärmeKabelTeknik 2

Index

History ................................................................................................................................................................................. 3

General about roof applications ......................................................................................................................................... 3

Rule of thumb for power feed ............................................................................................................................................ 3

Choosing material ............................................................................................................................................................... 3

Problem issues/icicles ......................................................................................................................................................... 4

The solution of the problem ............................................................................................................................................... 5

The construction of the system .......................................................................................................................................... 6

Heating lengths ................................................................................................................................................................... 7

Accessories, junction boxes, protective channels ............................................................................................................... 8

Accessories, Clips ................................................................................................................................................................ 9

Control, function ............................................................................................................................................................... 10

Control cabinets ................................................................................................................................................................ 11

Installation ........................................................................................................................................................................ 12

Installation tip ................................................................................................................................................................... 13

Education .......................................................................................................................................................................... 14

Suggestion on sketch for projecting ................................................................................................................................. 15


3

General about roof applications

In most cases a new supply cable must be installed from the distribution box of the building (often in the ground floor or basement) to provide the roof application with power.

At larger applications a slave distribution box are placed in the attic in order to distribute the power to the control cabinet. The slave cabinet should be provided with an energy meter to measure the power consumption of the roof application. All slave cabinets should be provided with lockable main switch to prevent electrical accidents at maintenance work.

The number and size of the control cabinet depends on the size and shape of the roof.

Rule of thumb for power feed:

Calculate the total amount heating cable by sum the number of meter roof / Gutter which are to be frost protected.

Add the number of drainpipes x length plus 1 m per drainpipe if these are connected to the surface water.

The calculated total amount heating cable needed for your roof application x 50 W/m gives the total power required of the roof, add 20 to 30% in margin: 300m will then give > 300 x 50 x 1,3= 19,5KW

At roofs facing different cardinal points or roofs with long lengths should be divided into sections to improve the selectivity of control and to limit the cable run with connection cables on the roof.

Choosing material:

Where considerations must be taken to the heat of the sun during summer‐time in combination with UV‐radiation brings high temperatures and ice and cold in winter‐time causing a rough environment, which required great demands on material used on roofs. Thus, the material should withstand temperatures down to ‐25‐30 degrees below 0 and up to 50‐60 degrees above 0 without taking any damage.

These requirements exclude largely all installations and heating cables with PVC‐sheath. Suitable choice of material is thermoplastic/rubber /fluorpolymer.

Consideration to galvanic currents should be taken when choosing material in fastening devices, due to a faulty choice could result in roof cover panel corrodes in a short time.

We believe there are cause to change of the installation methods for roof applications due to the severe failures causing risk on damages on persons and properties.

A close cooperation with “Elsäkerhetsverket” and ”Plåtslagarnas Riksförbund” have made us recommend that in the future only use the material which withstand requirement6s on these environments.

Easy installation and Service. Velox Frost protection of roof – the only system with plug connection. This reduces the work of the electrician out on the roof where experienced tin-men with ease installs and connects heating cable standard lengths. A electrician is however required for pulling the supply cable and installation of distribution box, control cabinet and connection boxes on the roof.


Dimensioning

ICICLES

Icicles on roof are formed when snow and ice are melting on the roof despite that the air have a temperature below 0 degrees.

Causes:

1. The most common cause to icicles are midday thaw, i.e. the sun is shining on the roof and melts the snow and ice despite degrees below 0 in the air, the melting water then escapes to the gutter and further down the drainpipe. Since the house surface are shadowed by surrounding buildings, the melting water freezes in the drainpipe.

2. Heat loss due to changed presumptions in the usage of the house, attic spaces are more often used as residences and offices in order to better exploit the areas of the building. This, however, brings the origin roof construction with a chiller attic and the roof insulation are replaced with a ventilated pocket nearest the outer roof with a underlying insulation which are minimized to prepare a maximum roof height.

3. Ventilation spill from aggregate located on the roof and calorific machines emitting heat aginst the roof.

Problem:

Icicles when falling against the ground can cause damages on people and property.

Frost damages on roof dewatering‐system such as gutters and pipes are destroyed by frostburst as a result of melting‐water freezes in the gutters and pipes which are not heated by above given causes.

Damage caused by putrefaction on barge‐boards and front in consequence of melting‐water overspill gutters.

Damage caused by putrefaction in roofs as a consequence of leaking roof cover panels / ceiling paper in box gutters, valleys, windows etc.

Velox Frost protection of roofs – The only system with plug connection. Electricians wont be needed on the roof.

Easy installation.

Electrical requirements for connection of control cabinets to distribution box and in some cases pulling of cable from control cabinet to distribution box on the attic.


5

The solution of the problem:

1. At midday thaw you must ensure that the melting‐water can find it’s way to a frostless waste pipe. To let the melting‐water flow out on the pavement is just to move the problem. Besides there are often problems at ejectors due to ice formation under the ejector, sealing up the ejector.

2. The heat loss at increased usage of attics often gives the same symptoms as midday thaw and is then handled in the same way.

3. At ventilation spill and calorific machines one should ensure that the melting‐water are prepared for a drainage channel on the roof so that ice do not form between the melted area and the dewatering‐system. Heating cable is then mounted with protective channels in the direction of fall of the roof so that a free passage is prepared.

Installation:

When connecting drain pipes to surface water the heating cable should run down at least one meter below surface level and at roof well with belonging waste pipes (the waste pipe should be heated down to 1m in heated area since down‐draught in the pipe could cause freezing even here).

Gutters are installed with heating cable of self‐limiting type which is protected mechanically by stainless channels. The channel is fixed in the gutter with special clips.

At the drain‐pipes outlet a heating cable is attached with stainless roof hook and then hanging free down the pipe.

At the waste pipe at the roof, heating cable can be allowed to run down in the well and then turn upwards to limit the number of connection points.

In gutters, box gutters with angles it is important to install heating cable in the angle to avoid frost‐burst. Here 2‐4 cable runs are often installed in the centre of the gutter for dewatering. At angled profiles on the gutter also a cable run in each angle.

Heating cable

down to ejector

At least 1m

down with

heating cable

Surface sewer


The construction of the system – Type of heating cable

Self‐limiting heating cable HS‐2 36W/m 230VAC.

• This type of heating cable have many advantages:

• Heating lengths can be adapted on the site with simple tools.

• Energy saving – the power of the heating cable varies after requirements, on dry roof approx. 18W/m and in water/ice up to 40W/m.

• HS‐2 is protected against overheating since emitted power decreases with rising temperature, this allows for direct installation against combustible bases such as roof paper and canvas of butyl without taking any damage.

• The heating cable can be laid double without risk of overheating.

Components:

In the system there are standard components which can be combined to larger and smaller applications.

• Heating cables in standard lengths with mounted plugs of tension unloaded, water‐tight type.

• Installation kits for length adaption of heating cable.

• Junction boxes in UV‐stabile plastic with mounting bracket in stainless steel.

• Stainless protective channels in 1 m lengths.

• Mounting clips in stainless spring steel with adapted dimensions.

• Mounting clips for supply cables.

• Distance clips in stainless steel for installation of heating cables in drain‐pipes.

• Caution labels.

Clip holding cable and channel on it’s place in a gutter

Example on inlet of Stainless roof hooks in cables from roof to attic different colours Available in green – black- Brown


7

Control

VELOX ROOF SYSTEM HEATING LENGTHS

Heating cable element for frost protection of gutters and drain‐pipes with protective channels and fixing devices.

Heating cable HS‐2 in standard lengths with mounted plug of water‐tight type.

Maximum length of the cable

Dependant on fuse

The size of the fuse

HS‐2 installed on roof

10 A

25 m

16 A

45 m

20 A

55 m

Values in the table take consideration to start‐current when using self‐limting cable type HS‐2.

A: Copper conductors B: Self‐limiting material C: Thermoplastic insulation D: Aluminium foil E: Fluor plastic sheath

Note! Heating cable is double insulated. All heating cable on roofs shall be installed first and covered by protective channel.

Heating lengths for roof

Part.no Length Power Fuses Part.no Length Power Fuses

3400001 1 m 36 W 10A 3400021 21 m 756 W 10A 3400002 2 m 72 W 10A 3400022 22 m 792 W 10A 3400003 3 m 108 W 10A 3400023 23 m 828 W 10A 3400004 4 m 144 W 10A 3400024 24 m 864 W 10A 3400005 5 m 180 W 10A 3400025 25 m 900 W 10A 3400006 6 m 216 W 10A 3400026 26 m 936 W 16A 3400007 7 m 252 W 10A 3400027 27 m 972 W 16A 3400008 8 m 288 W 10A 3400028 28 m 1008 W 16A 3400009 9 m 324 W 10A 3400029 29 m 1044 W 16A 3400010 10 m 360 W 10A 3400030 30 m 1080 W 16A 3400011 11 m 396 W 10A 3400031 31 m 1116 W 16A 3400012 12 m 432 W 10A 3400032 32 m 1152 W 16A 3400013 13 m 468 W 10A 3400033 33 m 1188 W 16A 3400014 14 m 504 W 10A 3400034 34 m 1224 W 16A 3400015 15 m 540 W 10A 3400035 35 m 1260 W 16A 3400016 16 m 576 W 10A 3400036 36 m 1296 W 16A 3400017 17 m 612 W 10A 3400037 37 m 1332 W 16A 3400018 18 m 648 W 10A 3400038 38 m 1368 W 16A 3400019 19 m 684 W 10A 3400039 39 m 1404 W 16A 3400020 20 m 720 W 10A 3400040 40 m 1440 W 16A

The heating lengths are delivered as standard with 3 meter connection cable and special plug. Other lengths on request. Suitable junction box


Deicing roof hook, canopy and larger roof surfaces (TCPR)

Accessories

In the system there are standard components which can be combined to larger and smaller applications.

Mounting kits for length adaptation of heating cable (is carried out with simple tools)

Part.no Denomination

1500505 Shrinking tubing kit for length adaptation of heating length HS‐2. End termination

3400205 Shrinking tubing kit for end termination HS‐2

Connection box in UV-stabile plastic with mounting bracket in stainless steel

The box is provided with 2 or 3 special outlets of water‐tight tension unloaded type for an easy connection of cable element.


3400301 Connection box 2 x 10A


3400303 Connection box 2 x 10A + 1 x 16A

3400304 Connection box 2 x 16A + 1 x 10A



3400320 Rf. Mounting plate, connection box 230x160

Stainless protective channels in 1 m lengths

The channel is U‐shaped and is placed above the heating cable as a mechanical protection.


3400401 Stainless protective channel – internal width 12mm

3400402 Stainless protective channel internal width 12mm Flexible

3400403 Stainless protective channel – internal width 16mm

3400404 Stainless protective channel – internal width 16mm Flexible

Distance cl ip in stainless steel Used for installation of heating cable in drain‐pipes.


3400501 Stainless distance clip for gutters

8999245 Stainless distance hook for gutters SAFE‐T.

Junction box

Stainless console for junction box on edge.

Mounting kit


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Mounting cl ips in stainless spring steel

Clips intended for fixing heating cables and protective channel in the gutter.

The clips are available for gutter 8cm – 24cm with 2cm sections, 8‐10‐12‐ etc.

Part.no Denomination Length

3400600 Rf‐clip 49mm roof‐foot gutter black 56 mm










3400610 Rf‐clip 49mm roof‐foot gutter green 56 mm










3400620 Rf‐clip 49mm roof‐foot gutter reddish‐brown 56 mm





3400625 Rf‐Clip 49mm roof‐foot gutter reddish‐brown 160 mm




3400630 Rf Mounting clip gutter 5 – 6”

3400631 Rf clip for connection cable on edge

Clip for roof‐foot gutter in adpted lengths

Connection cable on folding


Control Distribution central Distribution central for connection of supply cable from destribution box. Suitable for 4‐5 conductor systems.

Diazed fuses for outgoing groups. Can be obtained with kWh‐counter.

Part.no Denomination #Cabinets

3400701 Distribution central 2 x 3‐phase

2 pcs

3400702 Distribution central 3 x 3‐phase

3 pcs

3400703 Distribution central 2 x 3‐phase/KWh

2 pcs

3400704 Distribution central 3 x 3‐phase/KWh

3 pcs

CONTROL We recommend control with double thermostat. With this an economic control with good function is obtained. The price for a double thermostat allows more units to be installed on the roof where different conditions are present (for example different cardinal points) which benefits the function at the same time limit the operation to the parts of the roof application where heat is needed.

The function of the double thermostat consist in that the application is activated when ” sensor + ” (mounted in protective pipe against the roof) feel the melting‐temperature and “sensor – “ (which are mounted in shadow on the northern wall) indicates that that air have a freezing temperature. The temperature setting is adjustable to compensate unfavorable location on the roof.

At roof applications with roofs in the different cardinal points a cabinet is used for each cardinal point to obtain better selectivity (improved function to lower power consumption). We combine this thermostat with components from Siemens such as automatic fuses, ELCB, contactors, operating and main switch. In the cabinets there also are current sensing LED‐indicators, marked with correspondingly to the installed heating lengths , hereby one can establish if the application works and if error should arise one can directly see which heating length is faulty.

Slave central with 3 control cabinets, one for each cardinal point – west – south, yard

Thermostat

Distribution box

Slave central


11

Control Automatikskåp

The purpose with control equipment is to achieve maximum function to lowest possible cost.

Double thermostats with two transmitters control operation of the heat by reading the melting temperature on roofs in combination with frost temperatures in the outdoor temperature.

Part.no Denomination # Lengths3400711 Control cabinet 11‐ROOF 3 pcs3400721 Control cabinet 21‐ROOF 6 pcs3400731 Control cabinet 31‐ROOF 9 pcs3400741 Control cabinet 41‐ROOF 12 pcs3500711 Control cabinet 11‐ROOF‐LCD 3 pcs3500721 Control cabinet 21‐ROOF LCD 6 pcs3500731 Control cabinet 31‐ROOF LCD 9 pcs

The Double thermostat is the brain of the system (are included in cabinets 3400711- 3400731)

Thermostat 1442 has 2 transmitters where one of them is mounted in a protective pipe on the roof and the second in a shadowed northern wall.

The thermostat has such price that one can divide tha application i multiple parts without the cost shoot up, more controls gives an improved function to a lower operational cost. The thermostat start‐up the application when snow on the roof melts and the air have freezing temperature. The temperature settings are adjustable.

Function indication (included in all cabinets)

We have assembled current‐sensing operational indication where each heating length has a signal lamp showing that the heating length is operational.

Other components (included in all cabinets)

We use Siemens quality components in our cabinets such as; ELCB, automatic fuses, main switch, alteration switch, ensuring soperational safety and easy exchange since the program is available at most wholesalers.


Installation / Connection

The basic installation of the application with control cabinets and supply cables are carried out by an authorized electrician.

Installation of plug‐connected heating cables can be done by a tin‐man, experienced doing work on high roofs and which are correct equipped for these kind of work. Adaptation of sheet details are simplified and exchange of eventual damaged or flaw parts of the heating application can be done in combination with maintenance of the roof.

The control cabinet is constructed for 3‐9 heating lengths. Control with double thermostats are relatively cheap. This allows a number of smaller control cabinets with separate control system are mounted in the attic connected to slave cabinets with an energy‐meter. This construction also admits a good selectivity since the location of the transmitters comes in direct connection to the part of the roof which the thermostats serves.

A system with several smaller control cabinets simplifies the installation since the connection cables to the junction boxes can be limited.

The control equipment have an operational indication showing real function by measuring the current in each heating length. The function of the heating lengths are indicated by lamps with reference marking to the connected heating lengths.

The location of the heating length should be marked on an easily available roof sketch in order to give a quick overview of eventual errors at inspection before the cold season.

Exchange of defect material should be simplified by making the connection point easily accessible.


13

Installation tip

Junction boxes/Connection devices:

Cable entries in the roof often gives reason to leakage, since powerful temperature changes, hard weather and sliding ice easily corrupts the sealing ability of the entry.

Our studies have made us always recommending that all cable entries are done at the upturn of the roof.

The valley on these lies well protected and eventual leakages are quickly detected and easily fixed.

Installation of connection cables on roofs should follow foldings in order to easily be attached, mass distortion with advantage be done under the foot‐bridge which always shall be found on all roofs. Attach the cable with UV‐resistant clips/strips, stainless or made of plastic material.

Installation of heating cable

The choice of heating cable should have enough power to ensure transport of melting‐water and be done with consideration to the outer sheath to be made of UV‐stabile material. Self‐limiting heating cables admits furthermore a energy saving power which is important considered high costs for power consumption.

Of most importance for the function of the heating cable is though that they are installed correctly in order to make maximum usage.

What appears are that heating cable on roofs shall be attached in such a manor that they keep the position in the gutters etc and that they have a good contact against the foundation. Furthermore shall attachment at down‐goings in drain‐pipes be made satisfactory and that heating cable in drain‐pipe shall reach frost‐free depth at connection of drain‐pipes to surface water.


Education

Real‐estate companies, electricians, tin‐men, consultants and caretakers, shall be offered education in planning and installation of roof applications.

Värmekabelteknik undertakes total turnkey contract of typical roof applications where we co‐operate with tin‐men and electrician companies with a view to increase the knowledge and insight of the problems occurring at installations.

This is done during 2006‐2007 in co‐operation with tin‐men, member in PLR.

We hope that in this way be able to offer complete solutions, with optimum functioning products to prevent the lacks in roof applications today.

Our goal is also by regular maintenance of roof applications minimize the risk of damages on people and property and in this way reduce costs for compensations and repairs of buildings.

An improved system with simplified maintenance where through a push on a button at the control cabinet can read the function of the heating cables installed.

Ett förbättrat system med förenklat underhåll där man genom en knapptryckning vid automatikskåpet kan avläsa funktionen hos de värmekablar som monterats. Bör även leda till att underhåll blir utfört vart år då kostnaden för funktionskontrollen blir ringa. Underhållsarbetet kan utföras under den varma årstiden då taket är lättillgängligt vid eventuella utbyten av komponenter.

Detta samarbete kommer då att leda till fördelar för samtliga inblandade parter.

Det är lätt att dimensionera:

Börja med att leta rätt på en takplan eller mät ut antal meter ränna och stuprör som skall frostskyddas i vart väderstreck.

För att få rätt på totalt kraftbehov:

Totalt meter antal kabel x 50W (+ 20‐30% i reserv för startström)

Fördela sedan värmekabel slingorna så att dessa täcker en sträcka mellan två stuprör, i ett stuprör eller vid korta stuprör så att en slinga täcker en taklängd + ett stuprör max 25 meter.(se skiss nedan).

Driftskostnaden för anläggningen blir relativt låg, du kan beräkna effekten ca. 50% av den kraftkalkyl vi gjorde längre upp på denna sida. Antal driftimmar är lite svårare att sia om, men med ett snävt spann på termostatinställningen (nära 0°C) kommer anläggningen endast att vara i drift när temperaturen ligger mellan 0°C & ‐3°C.


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Beställningssunderlag

kommer


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Anteckningar

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Telephone: +46‐301‐418 40 – Email: [email protected] – Homepage: www.vkts.se

Industrihuset Södra Hedensbyn 43

S‐430 64 HÄLLINGSJÖ S‐931 91 SKELLEFTEÅ

Sweden Sweden

Fax: +46‐301‐418 70 Fax: +46‐910‐881 33

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