Danfoss Ground application. Ice & Snow Melting Application guide

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Ground application. Ice & Snow Melting

Application manual

Let Danfoss do the work

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.

The value of experience

We have installed literally thousands of systems across the globe, in every conceivable setting. This experience means that we can offer you practical advice about precisely which components you need to get the best results at the lowest cost.

Ground application. Ice & Snow Melting

This design guide presents Danfoss’s recommendations for design and installation of ice and snow melting systems for ground application.

It provides guidance for heating cable positioning, 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.

Our quality management system and compliances

ISO 9001

TS 16949

ISO 14001

Along with full compliance with EU directives and product approvals

Index

1. Application Briefing	4
2. System Description	5
3. Products	6
4. System Design	10
5. Installation	15
6. Appendixes	19
7. Cases	24

1. Application

Briefing

Winter weather costs

In recent years there have been plenty of new stories about human and financial costs caused by harsh winter weather. Property damage, increased maintenance expenses, lost productivity, rising insurance premiums, personal injuries and even worse. Installation of Danfoss Ice &

Snow Melting System ensures a steady solution to address cold weather related problems.

Danfoss’s ice and snow melting system is designed to provide safety for people, vehicles, and buildings safety through safe walking and driving during winter and safety in terms of less damage to buildings.

Ground solutions –

with a first class product range

By using Danfoss heating cables and mats controlled by electronic thermostats with moisture sensors, you can cost-effectively protect large areas such as parking areas, ramps or pedestrian accesses to buildings giving you convenience and safety while saving a lot of tiring and timeconsuming manual work.

One of the greatest advantages of these systems is the most energy efficient solution for the ground ice and snow melting applications.

Benefits

•Efficient snow removal - area is kept free from ice and snow at all times

•No manual snow removal and salting becomes unnecessary.

•Safe traffic and working areas for people

•Flexible system for most common surface covering materials

•Cost saving for outdoor surface repair after winter

•Environment is protected against salting and antifreeze related damages.

•Automatic ”Around the Clock” snow clearing service.

•Smart 2-zone control with low energy consumption

•Prioritizing – limited power output solution

•A maintenance free system with 20 year full warranty on cables

4 Application manual · Ground application. Ice & Snow Melting · VGHWD102 · ©Danfoss

2. System Description

Main purpose of the system is to melt and remove snow and ice from ground surfaces.

The most common Danfoss ice and snow melting ground applications are in residential car parking areas, driveways, pavements, outdoor steps, loading platforms, ramps, bridges and drainage areas. It is even possible to melt snow and ice on mastic asphalt surfaces by using special heating cables.

When heating cables are installed to melt snow or slippery ice on the

ground, safety and cost saving go hand in hand.

It can be done manually or in a smart way – by means of electrical Ice & Snow Melting system with thermostat control and moisture and temperature sensors that can control 2 zones simultaneously. Inactive during cold but dry weather 2 zone control saves energy and reduces costs.

The automatic regulation of the snow melting system keeps areas free from snow and passable at all times – night and day.

When installing ice and snow melting systems on steep slopes it may be necessary to provide some drainage for melted water at the slope bottom. The drain system should also be protected against ice formations.

Application manual · Ground application. Ice & Snow Melting · VGHWD102 · ©Danfoss 5

3. Products

Electrical heating system consists of two major components:

•Heating element – heating cable or heating mat;

•Thermostat with a temperature sensor or regulator/controller with temperature and moisture sensor(s).

Heating cables and mats for Ground applications are usually installed into concrete construction or into special glue under tiles.

Danfoss heating cables and mats for Ground applications are designed for installation in concrete constructions or into special glue under tiles. Usual thickness of top/finish concrete layer for outdoor applications is at least 5 cm. But the thickness should comply with a ground construction and local norms and regulations.

Heating cables used in ground constructions are serial resistive cables, single or twin conductor. Most of cables and mats are manufactured as ready-to-install heating elements wth a specific length (i.e. 7, 10, 15, up to 229 m), with connecting power supply cable (cold lead or cold tail) and sealed joints (muffs or end terminals).

Range of heating cables linear output for ground application is usually 15-30 W/m. Danfoss ready-made cables are available with 18, 20,

30 W/m output (for 230 and 400 V).

Most Danfoss cables are manufactured and approved in accordance with the latest revision of IEC 60800:2009, with M2 mechanical strength class (for rough concrete constructions).

The main type of Danfoss heating cables is twin conductor heating cables. Internal design of a modern twin conductor ECflex cable are shown in the figure below.

Heating elements

For Ground Ice and Snow Melting systems the following resistive (constant wattage) heating elements can be used.

Heating cables:

•Twin conductor ECflex 18T and ECflex 20T (230 V);

•Single conductor ECbasic 20S (230 V);

•Twin conductor ECsafe 20T (230 V);

•Twin conductor ECsnow 20T and ECsnow 30T (230/400 V);

Note. The number at the end of the cable’s and mat’s name refers to its linear output – W/m or area output – W/m², at 230 V or 400 V.

Letter “T” means twin conductor cable/mat (Twin), letter ”S” – singleconductor cable/mat (Single).

Danfoss resistive heating cables ensure safe, efficient and economical ground application.

To ensure long life-time and quality all cables are thoroughly inspected including tests for ohmic resistance, high voltage and material control.

The most used heating elements for Ground Ice and Snow Melting systems are ECbasic, ECflex and ECsafe heating cables.

ECflex. It is a twin conductor fully screened heating cable for installation in concrete, 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, sealed joints and end muffs.

Cable diameter is Ø 6,9 mm.

The cable is available for 230 V power supply.

Cables of 18 and 20 W/m (230 V) linear output are available.

Cable length:

ECflex 18T: 7,3-150 m ;

ECflex 20T: 7,1-148 m.

ECflex

ECbasic. It’s a single conductor screened heating cable complied with IEC 60800:1992 class C and intended for installation in concrete, for pipe heating etc. It’s supplied in readymade sets with 2 x 3 m cold leads and

2 sealed connection muffs.

Outer coating made of PVC

Protective screen foil (Aluminum)

Protective conductor

Internal insulation ( XLPE)

Heating element (resistance thread)

ECflex heating cable construction

6 Application manual · Ground application. Ice & Snow Melting · VGHWD102 · ©Danfoss

Cable diameter is Ø 5,5 mm.

ECbasic 20S is available with

20 W/m output for 230 V power supply.

Cable length:

ECbasic 20S, 230 V: 9-228 m.

ECbasic 20S readymade

ECsafe. It is a twin conductor fully screened heating cable for installation on roofs, in gutters, down drain pipes and on the ground.

The cable has UV stable tough outer sheath which 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 2,5 m cold lead, sealed joints and end muffs.

Cable diameter is Ø 7 mm.

The cable is available with linear output of 20 W/m for 230 V power supply.

Cable length:

ECsafe 20T, 230 V: 6-194 m.

ECsnow. It is a twin conductor fully screened heating cable for installation mainly on roofs, in gutters, down drain pipes. It can be an option for installation on the ground too. The cable has UV stable tough outer sheath, FEP conductor insulation, it 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 2,5 m cold lead, sealed joints and end muffs.

Cable diameter is Ø 7 mm.

ECsnow

The cable is available with linear output of 20 W/m and 30 W/m in two options for 230 V and 400 V power supply.

Cable length:

ECsnow 20T, 230 V: 12-205 m; ECsnow 30T, 230 V: 8,5-215 m.

Fixing

In case of heating cables application,it is recommended to use fittingbands to fix the cable to the base, e.g. ECfast metal galvanized fitting band (see Appendix A.2 ). It should be attached to the ground (e.g. nailed down) in parallel lines usually at intervals of

50 cm or using 2 meters of fitting band per each square meter of cable installation. The same applies to plastic bands.

ECfast

Control

Ice and snow melting systems are different and require different thermostats/regulators.

EFET/EFIT thermostats and regulators are fitted with a complete set of control functions for heating systems for ice and snow melting of any type and allow attaching external sensors for measuring ground temperature as well as control of moisture conditions.

The product range of controls is designed for ground outdoor systems including the following:

•thermostats with a temperature sensor – EFET 330 (5…45 °C), EFET 610;

•regulator with an integrated temperature and moisture sensor(s)

– EFIT 850.

To control simple or low output systems a thermostat with a ground temperature sensor is recommended. EFET 330 (5…45 °C) thermostat

with the DIN rail attachment is recommended as a standard solution. Also can be used EFET 610, IP44 with on wall/pipe mounting.

As an alternative to control small areas near private houses etc. EFET 130 wall mounted room thermostat can be used.

All thermostats above are supplied with a wire temperature sensor – NTC 15 kOhm @25 °C, 3 m.

To control ice and snow melting systems especially with high output the best solution is EFIT 850 regulator/ controller with integrated ground and roof moisture and temperature sensors.

EFIT 850 is a two-zone controller with possibility of connection up to 4 sensors to provide maximum control of the outdoor heating system. Comparing to installations with typical ground temperature measuring this regulator ensures reducing energy consumption costs by up to 40%.

EFET 330 (5…45 °C) with wire sensor in set

EFIT 850

with ground sensor

EFET 610

EFET 130

Application manual · Ground application. Ice & Snow Melting · VGHWD102 · ©Danfoss 7

Zone support saves energy

The EFIT 850 lets you divide your area in to 2 zones, e.g. a North and South side. In this way it is possible to save energy, when the South side is free of ice and snow faster because of the heat from

the sun.

Prioritizing – for limited power output

You can prioritize between the zones, e.g. if you have limited power output. This way one zone is made ice and snow free before focus is put on the other zone.

A

B B A B

Products – general overview for Ground ice and snow melting systems

	Product	Options	Description
	Resistive heating cable	ECflex 18T, 230 V;	Twin conductor, 100% screen, red.
			18, 20 W/m (230 V).
	ECflex	ECflex 20T, 230 V
			DIN IEC 60800:2009 M2
	Resistive heating cable	ECbasic20S,	Single conductor, wire screen, red.
			20 W/m (230 V).
	ECbasic 20S	230 V
			DIN IEC 60800:1992 C
	Resistive heating cable	ECsafe 20T,	Twin conductor, 100% screen, UV stable, black.
			20 W/m (230 V).
	ECsafe 20T	230 V
			DIN IEC 60800:2009 M2
		ECsnow 20T,	Twin conductor, 100% screen, FEP conductor insulation, UV stable,
	Resistive heating cable	230 & 400 V program;	black.
	ECsnow	ECsnow 30T,	20 and 30 W/m (230/400 V).
		230 & 400 V program	DIN IEC 60800:2009 M2
	Fixing	ECfast Metal	25 m pack; galvanized metal, fixings every 2,5 cm.
	Regulator		Connection to Ground and Roof moisture and temp. sensor, max 4
		EFIT 850	sensors, 2 zones,
	EFIT
			2x15 A, PSU 24 V, DIN rail
	Moisture & temperature	Ground sensor	Ø93 x 98 mm, IP67, 15 m connection cable 4x1 mm²
	sensor	for EFIT 850
	Accessories	PSU 24 V	Extra PSU for EFIT 850 with 3-4 sensors
		for EFIT 850
	Thermostat	EFET 330 (5…45 °C)	5…45 °C, 16 A, IP20, with 3 m wire sensor,
	EFET		DIN rail
	Thermostat	EFET 610	-30…+50 °C, 10 A, IP44, with 3 m wire sensor,
	EFET		on wall/pipe installation
	Thermostat	EFET 130	5…45 °C, 16 A, IP30, with 3 m wire sensor,
	EFET		room on wall installation

For additional information please refer to the Danfoss Catalogue.

8 Application manual · Ground application. Ice & Snow Melting · VGHWD102 · ©Danfoss