SE542774C2

SE542774C2 - Heated DIN rail

Info

Publication number: SE542774C2
Application number: SE1950060A
Authority: SE
Inventors: Fredrik Grivans; Ulf Holgersson
Original assignee: Swerail Ab
Priority date: 2019-01-17
Filing date: 2019-01-17
Publication date: 2020-07-07
Also published as: SE1950060A1

Abstract

The present disclosure relates to a DIN rail (1) for mounting of electrical equipment. The DIN rail (1) comprising an elongated support section (2) with a front side (2') and a back side (2"), wherein the front side (2') comprising two elongated mounting flanges (3) along opposite sides of the front side (2"), for fastening the electrical equipment, and an elongated groove (4) therebetween. The DIN rail (1) comprises at least one heating element (5) arranged in direct contact with the support section (2) and that the at least one heating element (5) comprises at least one Positive Temperature Coefficient heater (6). The disclosure also relates to the use of the DIN rail (1) to heat mounted electrical equipment and DIN rail system comprising a circuit breaker mounted to the DIN rail (1) and electrically connected to the at least one heating element (5).

Description

HEATED DIN RAIL Technical field The present invention relates to a DIN rail and a DIN rail system for mounting of electrical equipment.

Background DIN rails are used for mounting circuit breakers and control equipment in racks. They are commonly made from cold rolled carbon steel sheet and can have a zinc-plated or chromated bright surface finish. The DIN rail is for mechanical support of the circuit breakers and control equipment There are three major types of DIN rail: Top hat rail, C-section rail and G-section rail. And within these types, there are many variations, some of which are: Top hat rail IEC/EN 60715 - 35 x 7.5. It is known as the TS35 rail in the US Top hat rail IEC/EN 60715 - 35 x 15. It is also known as the TS35 rail in the US mm x 7.5 mm top-hat rail (EN 50022, BS 5584, DIN 46277-3) Miniature top-hat rail, 15 mm x 5.5 mm (EN 50045, BS 6273, DIN 46277-2) 75 mm wide top-hat rail (EN 50023, BS 5585) C20 (The number suffix corresponds to the overall vertical height of the rail: e.g.: AS 2756.1997(C3) C30 C40 C50 EN 50035 (G32 in the US), BS 5825, DIN 46277-1 The DIN rails are all elongated rails with an elongated flat back part that is to be fastened to a suitable surface. They also have two protrusions on the upper and lower side of the elongated flat back part for mounting electrical equipment. The protrusions have different shapes and dimensions for the different types. Different cross sections of DIN rails are illustrated in figure 1 to 3. Figure 1 illustrates a Top hat rail, figure 2 a C-section rail and figure 3 a G-section rail.

A problem in rack cabinets, especially those who are located outdoors, is the varying temperature in the cabinets. Circuit breakers are designed to break the current to a circuit at exceedance of a predetermined Ampere. If the temperature in the cabinet gets very low, the circuit breakers may malfunction and break the current at much higher load than specified, i.e. at higher Amperage.

Another problem is that systems located in cold environments often accumulate condensation, which can damage electronic components.

A solution for the above is to put an electric heater inside the cabinet with a temperature controller so that that a desired temperature can be maintained in the cabinet.

Summary It is an aim of the present invention to at least partly overcome the above problems, and to provide an improved way to avoid condensation around electrical equipment in cabinets, to maintain a good working temperature for the electrical equipment as well as saving energy.

The present disclosure aims to provide a DIN rail for mounting electrical equipment and a DIN rail system including a circuit breaker.

This aim is achieved by the DIN rail as defined in claim 1 and the DIN rail system as defined in claim 15.

According to an embodiment of the disclosure, it comprises a DIN rail for mounting of electrical equipment. The DIN rail comprises an elongated support section with a back side and a front side, wherein the front side comprises two elongated mounting flanges along opposite sides of the front side, for fastening the electrical equipment, and an elongated groove therebetween. The DIN rail comprises at least one heating element arranged in direct contact with the support section and the at least one heating element comprises at least one Positive Temperature Coefficient heater. When mounting electrical equipment on the DIN rail, the electrical equipment will be heated both through thermal radiation from the heaters and the DIN rail and by thermal conductivity through the DIN rail. By heating the DIN rail and by having the heating elements so close to the electrical equipment, there is no need to heat the whole rack cabinet to avoid condensation and malfunctioning circuit breakers. In other words, the circuit breakers are heated by the heated DIN rail and thus, there is no need for heating the cabinet and energy is thus saved. Since PTC heaters 6 are used, there is also no need for any additional circuitry for controlling the temperature due to the self-limiting nature of PTC heaters 6.

According to some aspects, the at least one heating element is arranged in the groove. When positioned in the groove, the heating elements are physically protected by the mounting flanges and the support section.

According to some aspects, the at least one heating element comprises a material surrounding the at least one Positive Temperature Coefficient heater, the material comprises silicone and has an outer shape such that it fits into the groove and is held in the groove by the mounting flanges. Silicone is a flexible material and it is therefore possible to put the heating element in the grove by pushing it in. The silicone will deform slightly at the edges to hold the heating element in place. This is a very efficient way to fasten the heating elements.

According to some aspects, the at least one heating element is fastened to the support section in the groove by means of at least one resilient element, the at least one resilient element being clamped between the two opposing mounting flanges such that it holds the at least one heating element in place in the groove. By using a resilient element, the heating elements may be attached in the groove instantly. This is also a cheap and fast way of securing the heating element.

According to some aspects, the at least one heating element is fastened to the support section by means of an adhesive. There are very strong adhesives and an adhesive is a fast and cheap way of attaching the heating elements to the support section.

Both using an adhesive and a resilient element for fastening the heating element may be used in an efficient way in mass producing the DIN rail.

According to some aspects, the at least one heating element comprises wiring for powering the at least one Positive Temperature Coefficient heater, the wiring being arranged in the groove. An advantage with this is that the wiring is physically protected in the groove by the mounting flanges. The wiring is thus protected from physical damage and from getting hooked on something during handling. Another advantage is that it is visually appealing to hide the wiring in the grove such that they are visually less apparent.

According to some aspects, the at least one heating element is attached to the back side of the support section. For simplifying mass production of the Din rail, the heating element may be attached to the back side of the support section. This may also be advantageous depending on the type of standard used for the DIN rail. For some standards, the heating element may be in the way of mounting the electronic equipment when located in the groove. In such cases, arranging the heating elements on the back side is advantageous.

According to some aspects, the at least one heating element is embedded in the material of the support section. This is advantageous especially in demanding environments where the heating elements and/or the wiring needs to be protected from the environment. This may also be a very secure alternative since a user of the DIN rail will not be able to access the heating element or its wiring.

According to some aspects, the at least one heating element comprises a plurality of heating elements arranged at a distance from each other along the elongated support section. DIN rails come at different lengths and they usually have holes at regular intervals in the support section for fastening to a surface using for example screws or the like. The heating elements may therefore be distributed with a distance between them so that the holes are accessible for fastening the rail.

According to some aspects, the plurality of heating elements are evenly distributed along a length of the elongated support section. That the heating elements are evenly distributed may be advantageous in production, since there is no resetting of the distances, and it may also be visually appealing with regular intervals between the heating elements.

According to some aspects, each of the at least one heating element comprises a plurality of Positive Temperature Coefficient heaters distributed in the heating element. PTC elements can be produced in various sizes and shapes and each heating element may therefore comprise one or several PTC heaters 6. For simplifying production, it may be advantageous with one PTC heater per heating element but more than one may give a more even spread of heat.

According to some aspects, the Positive Temperature Coefficient heaters are evenly distributed along a length of the heating element. An advantage with this is even heat distribution in the heating element.

According to some aspects, the Positive Temperature Coefficient heaters are arranged between two steel plates which are arranged along a length of the heating element, the Positive Temperature Coefficient heaters and the steel plates being embedded in an electrically insulating material.

According to some aspects, the at least one heating element has a maximum surface temperature between 30° and 45° Celsius and preferably a maximum temperature of 40° Celsius. The temperature is to ensure a good working temperature for electrical equipment mounted in the DIN rail. Electrical equipment is usually made for functioning best in room temperature or slightly above room temperature. A surface temperature between 30 and 45 degrees Celsius will provide optimal working conditions for the electrical equipment.

According to an embodiment of the disclosure, it comprises the use of the DIN rail according to any of the above features, to heat mounted electrical equipment.

According to an embodiment of the disclosure, it comprises a DIN rail system comprising a DIN rail according to any one of clams 1-13, the system comprising a circuit breaker mounted to the DIN rail and electrically connected to the at least one heating element. With a circuit breaker for the at least one heating elements already attached to the DIN rail, the DIN rail system provides a ready to use DIN rail which provides optimal working conditions for electrical equipment. The DIN rail system is thus easy to mount to a surface and connecting electricity to the circuit breaker.

According to some aspects, the circuit breaker is a miniature circuit breaker, MCB.

Brief description of the drawings The invention will now be explained more closely by the description of different embodiments of the invention and with reference to the appended figures.

Figure 1 illustrates a cross section of a Top hat rail Figure 2 illustrates a cross section of a C-section rail and Figure 3 illustrates a cross section of a G-section rail Figure 4 illustrates an example DIN rail comprising heating elements arranged in the groove viewed from above Figure 5 illustrates the DIN rail of figure 4 from the side Figure 6 illustrates a cross section of the DIN rail of figures 4 and 5 Figure 7 illustrates a cross section of an example DIN rail where the heating element is snapped into the groove Figure 8 illustrates the DIN rail of figures 4, 5 and 6 from a perspective view Figure 9 illustrates a cross section of an example DIN rail with an embedded heating element Figure 10 illustrates a cross section of an example heating element Detailed description Aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. The device disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

The terminology used herein is for the purpose of describing particular aspects of the disclosure only and is not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

As discussed in the background section, different cross sections of DIN rails 1 are illustrated in figure 1 to 3. Figure 1 illustrates a Top hat rail, figure 2 a C-section rail and figure 3 a G-section rail. DIN rails 1 are typically made from cold rolled carbon steel sheet with a zincplated or chromated bright surface finish. Although metallic, they are meant only for mechanical support, and are not used as a busbar to conduct electric current, although they may provide a chassis grounding connection.

A DIN rail 1 for mounting of electrical equipment is disclosed. The DIN rail 1 comprises an elongated support section 2 with a back side 2" and a front side 2', wherein the front side 2' comprises two elongated mounting flanges 3 along opposite sides of the front side 2', for fastening the electrical equipment, and an elongated groove 4 therebetween. In other words, the DIN rail 1 has first and second mounting flanges 3 extending lengthwise along opposite sides of the support section 2. In the examples of different DIN rail standards, these features are common for all standards. As can be seen in figures 1 to 3, as well as figure 6 which will be discussed below, the mounting flanges 3 are bent at some point to form a part that is parallel with the support section 2. Function and variations in shape and size of DIN rails 1 are common knowledge to a person skilled in the art and defined in the various standards discussed in the background section.

Electrical equipment is for example circuit breakers, industrial control equipment and the like adapted to be mounted on a DIN rail 1.

The DIN rail 1 presented in this disclosure comprises at least one heating element 5 arranged in direct contact with the support section 2 and the at least one heating element 5 comprises at least one Positive Temperature Coefficient heater 6. In other words, the support section 2 is heated by the heating elements 5 with Positive Temperature Coefficient, PTC, heaters. When mounting electrical equipment on the DIN rail 1, the electrical equipment will be heated both through thermal radiation from the heaters and the DIN rail 1 and by thermal conductivity through the DIN rail 1. By heating the DIN rail 1 and by having the heating elements 5 so close to the electrical equipment, there is no need to heat the whole rack cabinet to avoid condensation and malfunctioning circuit breakers. In other words, the circuit breakers are heated by the heated DIN rail 1 and thus, there is no need for heating the cabinet and energy is thus saved. Since PTC heaters 6 are used, there is also no need for any additional circuitry for controlling the temperature due to the self-limiting nature of PTC heaters 6.

There are several alternatives to where to arrange the heating element/elements 5 in direct contact with the support section 2 which will be further described below.

An advantage with using Positive Temperature Coefficient heaters 6, i.e. PTC heaters 6, is that no temperature sensors are needed to turn the heat on and off to keep the desired heat. PTC heaters 6 are resistive heaters and when PTC heaters 6 reach a certain temperature, the resistance increases so much that it is no longer heating up. In other words, a PTC material is designed to reach a maximum temperature, since at a predefined temperature, any further increase in temperature would be met with greater electrical resistance. PTC materials are thus inherently self-limiting in temperature so that there is no risk of the heating element 5 overheating. A PTC material does not get any hotter than the temperature where the resistance of the material increases rapidly. It is thus impossible for the PTC material to get hotter than the temperature it was manufactured for.

PTC heaters 6 are manufactured to have a predefined maximum temperature. The PTC heaters 6 are therefore chosen beforehand on what their maximum temperature is. The structure of the PTC heaters 6 will not be further discussed here since it is known to a person skilled in the art.

A PTC heater 6 may be manufactured in many different sizes, for example around 20x15x2 mm. The PTC heaters 6 are for example between 3 and 40 mm long, between 1 and 25 mm wide and between 0.1 and 5 mm thick.

An example of a DIN rail 1 comprising a heating element 5 is illustrated in figures 4 to 8. In the illustrated example the at least one heating element 5 is arranged in the groove 4. Electrical equipment is in general mounted on the mounting flanges 3. There is thus room for the heating element/elements 5 in the groove 4. When positioned in the groove 4, the heating at least one heating element is also physically protected by the mounting flanges 3 and the support section 2. In this example, the size and shape of the heating element 5 is such that it fits into the groove 4.

In figures 4 to 8 the elongated support section 2 and the two elongated mounting flanges 3 can be seen.

In the cross section of figure 6, it can be seen that this example DIN rail 1 has a cross section slightly different from the DIN rails 1 of figures 1 to 3. The mounting flanges 3 are more curved than those of the previous examples. The features presented in this disclosure are applicable to all DIN rail standards unless explicitly stated otherwise.

In the cross section of figure 7, an example way to fasten the heating element 5 in the groove is illustrated. According to some aspects, the at least one heating element 5 comprises a material surrounding the at least one Positive Temperature Coefficient heater 6, the material comprises silicone and has an outer shape such that it fits into the groove and is held in the groove 4 by the mounting flanges 3. Silicone is a flexible material and it is therefore possible to put the heating element in the grove by pushing it in. The silicone will deform slightly at the edges to hold the heating element in place. This is a very efficient way to fasten the heating elements. It may also be combined with any of the other ways to fasten it. To increase the thermal conductivity and the stiffness of the silicone it may be mixed with for example silicon. Other materials may be added to increase the thermal conductivity and/or the stiffness of the material.

One way to attach the heating element 5 in the groove 4 is to use an adhesive. Thus, according to some aspects, the at least one heating element 5 is fastened to the support section 2 in the groove 4 by means of an adhesive. There are very strong adhesives and an adhesive is a fast and cheap way of attaching the heating element/elements 5 to the support section 2. The adhesive may be thermally conductive so assist in transferring heat from the at least one heating element 5 to the support section 2. The adhesive is for example glue or a resin.

There are alternatives to attaching the at least one heating element 5 with an adhesive, such as using a clamp, cable ties or screws. According to some aspects, the at least one heating element 5 is fastened to the support section 2 in the groove 4 by means of at least one resilient element 7, the at least one resilient element 7 being clamped between the two opposing mounting flanges 3 such that it holds the at least one heating element 5 in place in the groove 4. In figures 4 to 7, resilient elements 7 are illustrated as pieces of material that is resilient and which is clamped between the inner sides of the mounting flanges 3. In the illustrated examples there are two resilient elements 7 holding each heating element 5, but it may also be that one or several resilient elements 7 are used to hold a heating element 5. The resilient element 7 is preferably made of a thermally conducting material. It may also be that the heating element/elements 5 is attached with both an adhesive and resilient elements 7. By using a resilient element 7, the heating element/elements 5 may be attached in the groove 4 instantly. This is also a cheap and fast way of securing the at least one heating element 5.

Another term for the resilient is restraint element because it is a resilient material that restraints the heating element 5 to the groove 4.

Using a resilient element 7 is preferably used in combination with a DIN rail standard where the mounting flanges 3 are curved, for example as the one shown in figures 4 to 8. The resilient element 7 is more easily secured to curved mounting flanges 3. The DIN rails 1 can alternatively be equipped with protrusions for securing the resilient elements 7.

Both using an adhesive and at least one resilient element 7 for fastening the at least one heating element 5 may be used in an efficient way in mass producing the DIN rail 1.

The at least one heating element 5 may comprise wiring 8 for powering the at least one Positive Temperature Coefficient heater 6. The wiring 8 is, for example, arranged in the groove 4. The wiring 8 is for example arranged in the bend between the support section 2 and the mounting flanges 3 as can be seen in the examples of figure 4 and 8. An advantage with arranging the wiring 8 in the groove 4 is that the wiring 8 is physically protected in the groove 4 by the mounting flanges 3. The wiring 8 is thus protected from physical damage and from getting hooked on something during handling. Another advantage is that it is visually appealing to hide the wiring 8 in the grove such that they are visually less apparent.

For simplifying mass production of the DIN rail 1, the at least one heating element 5 may be attached to the back side 2" of the support section 2. Depending on the method to produce the DIN rail 1, it may be advantageous to arrange the at least one heating element 5 on the back side 2". According to some aspects, the at least one heating element is attached to the back side 2" of the support section 2. This may also be advantageous depending on the type of standard used for the DIN rail 1. For some standards, the at least one heating element 5 may be in the way of mounting the electronic equipment when located in the groove 4. In such cases, arranging the heating element/elements 5 on the back side 2" is advantageous. The at least one heating element 5 may for example be attached to the back side 2" with an adhesive. Again, alternatives to attaching the at least one heating element 5 with an adhesive are using a clamp, cable ties or screws. Since the heating element/elements 5 are then arranged between the support section 2 and the surface the DIN rail 1 is attached to, it is preferred that the material of the at least one heating element 5 has a structural integrity to not be harmed when mounting the DIN rail 1. The at least one heating element may for example have an outer material of steel, silicone or a mix of silicone and silicon.

An alternative to arranging the at least one heating element in the back side 2" or in the groove 4, is to arrange it inside the material of the support section 2. An example of this is illustrated in figure 9, where the DIN rail 1 is a C-section DIN rail 1 with an embedded heating element. The feature is of course applicable to all DIN rail standards, not just the C-section. Thus, according to some aspects, the at least one heating element is embedded in the material of the support section 2. The support section 2 is in this case made in two layers with the at least one heating element 5 therebetween. This is advantageous especially in demanding environments where the at least one heating element 5 and/or the wiring 8 needs to be protected from the environment. This may also be a very secure alternative since a user of the DIN rail 1 will not be able to access the at least one heating element 5 or its wiring 8 if the wiring 8 is also embedded in the support section 2. Since the at least one heating element 5 is not accessible for users of the DIN rail 1, the life time of the DIN rail 1 may increase.

Both in the case when the at least one heating element 5 is arranged openly in the groove 4 or on the backside 2" and when it is arranged embedded in the material of the support section 2, the outer surface of the at least one heating element 5 is preferably not conducting a current. The PTC heaters 6 are thus electrically insulated from the surface of the heating element/elements 5. This may be done with for example an electrically insulating material arranged around the PTC heaters 6. The electrically insulating material is preferably thermally conducting to increase heat transfer to the surface of the at least one heating element 5.

There are many ways to realize and arrange the heating element/elements 5. According to some aspects, the at least one heating element 5 comprises a plurality of heating elements 5 arranged at a distance from each other along the elongated support section 2. DIN rails 1 come at different lengths and they usually have holes 10 at regular intervals in the support section 2 for fastening to a surface using for example screws or the like. The heating elements 5 may therefore be distributed with a distance between them so that the holes 10 are accessible for fastening the rail. If the DIN rail 1 is a short one, there may be only one heating element 5 comprised at the support section 2. According to some aspects, the plurality of heating elements 5 are evenly distributed along a length of the elongated support section 2. That the heating elements 5 are evenly distributed may be advantageous in production, since there is no resetting of the distances, and it may also be visually appealing with regular intervals between the heating elements 5. If the fastening holes 10 of the support section 2 are arranged at regular intervals, the heating elements 5 may be arranged regularly between the holes 10.

There may be one or more PTC heaters 6 in a heating element 5. According to some aspects, each of the at least one heating element 5 comprises a plurality of Positive Temperature Coefficient heaters 6 distributed in the heating element 5. PTC elements can be produced in various sizes and shapes and each heating element 5 may therefore comprise one or several PTC heaters 6. For simplifying production, it may be advantageous with one PTC heater per heating element 5 but more than one may give a more even spread of heat. According to some aspects, the Positive Temperature Coefficient heaters 6 are evenly distributed along a length of the heating element 5. An advantage with this is even heat distribution in the heating element 5.

The heating element 5 can be designed in different ways to realize desired properties. According to some aspects, the at least one heating element 5 has a maximum surface temperature between 30° and 45° Celsius and preferably a maximum temperature of 40° Celsius. The temperature is to ensure a good working temperature for electrical equipment mounted in the DIN rail 1. Electrical equipment is usually made for functioning best in room temperature or slightly above room temperature. A surface temperature between 30 and 45 degrees Celsius will provide optimal working conditions for the electrical equipment.

To reach a maximum surface temperature between 30° and 45° Celsius a small PTC heater with a higher maximum temperature may be used. The temperature is then decreased as the heat is conducted through the material of the heating element 5. For example, a PTC heater with a maximum temperature of between 70° and 100° Celsius may be used. Another way of realizing a maximum surface temperature is to have several PTC heaters 6 or a larger PTC heater with a maximum temperature close to the desired surface temperature. For example, 3 PTC heaters 6 with a maximum temperature of 50° Celsius may be used to reach a surface temperature of 45° Celsius.

Since PTC heaters 6 come in many variations in size and maximum temperatures, it is up to the designer of the system to choose which PTC heaters 6 to use and how many. Depending on what standard DIN rail shape is used, different sizes and maximum temperature PTC heaters 6 may be desirable. For example, it may be advantageous to use larger PTC heaters 6 for DIN rails 1 with a wider supporting section and smaller PTC heaters 6 for more narrow DIN rails 1.

There are different ways to power a PTC heater. One way is illustrated in figure 10, which shows a cross section of an example heating element 5. In the illustrated example, the Positive Temperature Coefficient heaters 6 are arranged between two steel plates 9 which are arranged along a length of the heating element 5, the Positive Temperature Coefficient heaters 6 and the steel plates 9 being embedded in an electrically insulating material. In other words, the two steel plates 9 are elongated and extend through a length of the heating element 5 and between those two steel plates 9, one or more PTC heaters 6 are arranged. Wiring 8 as show in the figures, is then connected to a respective plate to power the PTC heaters 6.

Another example of how the PTC heaters 6 may be powered is that the wires 8 going through the heating element 5 may be shaved so that they are not insulated where they abut the PTC heaters 6. In other words, the two wires 8, as can be seen in the figures, going through the at least one heating element 5 are arranged on opposite sides of the PTC heater/heaters 6 such that they abut the PTC heater/heaters 6 and in the contact area, the wires 8 are shaved to expose the conducting wires.

In the illustrated example of figure 9, the PTC heaters 6 are enclosed in a heat conducting material to form the heating element 5. The heat conducting material is for example aluminum or steel. In other words, the at least one heating element 5 comprises an aluminum or steel material embedded with one or more PTC heaters 6 with some kind of insulation and wiring 8. According to some aspects, the at least one heating element 5 has an elongated shape with PTC heaters 6 arranged in a row with a distance between them. According to some aspects, the at least one heating element 5 comprises two or more rows of PTC heaters 6.

The use of the DIN rail 1 according to any of the above features is to heat mounted electrical equipment, preferably in a rack cabinet or control cabinet.

For ensuring secure functionality of the DIN rail 1, it may be connected to a circuit breaker for protecting it from overload or short circuit. According to an embodiment of the disclosure, it comprises a DIN rail system comprising a DIN rail 1 comprising an elongated support section 2 with a back side 2" and a front side 2', wherein the front side 2' comprising two elongated mounting flanges 3 along opposite sides of the front side 2', for fastening the electrical equipment, and an elongated groove 4 therebetween. The DIN rail 1 further comprises at least one heating element 5 arranged in direct contact with the support section 2 and that the at least one heating element 5 comprises at least one Positive Temperature Coefficient heater 6. The Din rail system comprising a circuit breaker mounted to the DIN rail 1 and electrically connected to the at least one heating element 5. With a circuit breaker for the at least one heating elements 5 already attached to the DIN rail 1, the DIN rail system provides a ready to use DIN rail 1 which provides optimal working conditions for electrical equipment. The DIN rail system is thus easy to mount to a surface and connecting electricity to the circuit breaker. The DIN rail 1 of the DIN rail system can of course be according to any of the above described aspects since all of the above are combinable with a circuit breaker. The circuit breaker is designed to be fastened to the protruding parts of the DIN rail 1. According to some aspects, the circuit breaker is a miniature circuit breaker, MCB and it may also be a MCCB, Molded Case Circuit Breaker. The circuit breaker is not illustrated in the figures since any standard circuit breaker may be used that is suitable to use with the at least one heating element 5 and which is mountable to the DIN rail 1.

Reference list: 1. DIN rail 2. Support section 2'. Front side 2". Back side 3. Mounting flanges 4. Groove . Heating element 6. PTC heater 7. Resilient element 8. Wiring 9. Steel plate . Hole

Claims

1. A DIN rail (1) for mounting of electrical equipment, the DIN rail (1) comprising an elongated support section (2) with a front side (2') and a back side (2"), wherein the front side (2') comprising two elongated mounting flanges (3) along opposite sides of the front side (2'), for fastening the electrical equipment, and an elongated groove (4) therebetween, characterized in that the DIN rail comprises at least one heating element (5) arranged in direct contact with the support section (2) and that the at least one heating element (5) comprises at least one Positive Temperature Coefficient heater (6) and wherein the at least one heating element (5) is arranged in the groove (4).

2. The DIN rail (1) according to claim 1, wherein the at least one heating element (5) comprises a material surrounding the at least one Positive Temperature Coefficient heater (6), the material comprises silicone and has an outer shape such that it fits into the groove (4) and is held in the groove by the mounting flanges (3).

3. The DIN rail (1) according to claim 1, wherein the at least one heating element (5) is fastened to the support section (2) in the groove (4) by means of at least one resilient element (7), the at least one resilient element (7) being clamped between the two opposing mounting flanges (3) such that it holds the at least one heating element (5) in place in the groove (4).

4. The DIN rail (1) according to any preceding claim, wherein the at least one heating element (5) is fastened to the support section (2) by means of an adhesive.

5. The DIN rail (1) according to any preceding claim, wherein the at least one heating element (5) comprises wiring (8) for powering the at least one Positive Temperature Coefficient heater (6), the wiring (8) being arranged in the groove (4).

6. The DIN rail (1) according to any preceding claim, wherein the at least one heating element (5) comprises a plurality of heating elements (5) arranged at a distance from each other along the elongated support section (2).

7. The DIN rail (1) according to claim 6, wherein the plurality of heating elements (5) are evenly distributed along a length of the elongated support section (2).

8. The DIN rail (1) according to any preceding claim, wherein each of the at least one heating element (5) comprises a plurality of Positive Temperature Coefficient heaters (6) distributed in the heating element (5).

9. The DIN rail (1) according to claim 8, wherein the Positive Temperature Coefficient heaters (6) are evenly distributed along a length of the heating element (5).

10. The DIN rail (1) according to claim 8 or 9, wherein the Positive Temperature Coefficient heaters (6) are arranged between two steel plates (9) which are arranged along a length of the heating element (5), the Positive Temperature Coefficient heaters (6) and the steel plates (9) being embedded in an electrically insulating material.

11. The DIN rail (1) according to any preceding claim, wherein the heating element (5) has a maximum surface temperature between 30° and 45° Celsius and preferably a maximum temperature of 40° Celsius.

12. Use of the DIN rail (1) according to any one of claims 1-11, to heat mounted electrical equipment.

13. A DIN rail system comprising a DIN rail (1) according to any one of clams 1-11, the system comprising a circuit breaker mounted to the DIN rail (1) and electrically connected to the at least one heating element (5).

14. The DIN rail system according to claim 13, wherein the circuit breaker is a miniature circuit breaker, MCB.