EP2461643A1 - Système de mise à la terre pour la sécurité électrique - Google Patents

Système de mise à la terre pour la sécurité électrique Download PDF

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Publication number
EP2461643A1
EP2461643A1 EP11191493A EP11191493A EP2461643A1 EP 2461643 A1 EP2461643 A1 EP 2461643A1 EP 11191493 A EP11191493 A EP 11191493A EP 11191493 A EP11191493 A EP 11191493A EP 2461643 A1 EP2461643 A1 EP 2461643A1
Authority
EP
European Patent Office
Prior art keywords
current
conductor
layer
combination according
conductors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11191493A
Other languages
German (de)
English (en)
Inventor
Mathew Robins
Ryan Kwasnica
Gregory Gulyas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alternative Heating Systems Inc
Original Assignee
Alternative Heating Systems Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alternative Heating Systems Inc filed Critical Alternative Heating Systems Inc
Publication of EP2461643A1 publication Critical patent/EP2461643A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B1/00—Details of electric heating devices
    • H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
    • H05B1/0227—Applications
    • H05B1/0252—Domestic applications
    • H05B1/0272—For heating of fabrics
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
    • H05B3/34—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater flexible, e.g. heating nets or webs
    • H05B3/36—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater flexible, e.g. heating nets or webs heating conductor embedded in insulating material
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
    • H05B2203/026—Heaters specially adapted for floor heating

Definitions

  • This invention relates to an electrical safety grounding system.
  • a heating element includes two flexible plastics layers connected in overlying relationship with first and second conductors each running along the element between the layers the side edges with a row of printed conductive strips at right angles to the conductors.
  • a grounding layer comprising a sheet of foil laminated to a carrier is laminated to the heating element.
  • a reinforcing layer in the form of a bitumen anti-fracture membrane is applied on one surface and a reinforcing layer of a fiber reinforced material is applied on the opposite surface for engagement into a tile adhesive layer.
  • First and second strips of an electrically insulating material are applied over the first and second conductors to define slots allowing insertion into the slots of respective clamp type terminals.
  • the heating element comprises a flexible, electrically insulated polyester coated element in the form of an elongate sheet formed of top and bottom overlying layers of a polyester material where the element consists of two electrodes or bus bars running parallel the length of the element between the layers along the side edges.
  • a row of conductive ink strips are printed onto the top surface of the bottom one of one layer of the polyester at right angles to the electrodes, contacting the electrodes thereby setting up parallel electrical heating circuits across the elongate sheet.
  • the electrodes applied on top of the printed conductive heating strips can be formed of tinned copper and may cover a printed layer of a silver ink applied onto the edges of the bottom layer.
  • the printed heating conductors and the bus bars are covered by the top layer.
  • the heating element comprises a continuous serpentine heating wire embedded in or carried by a scrim to form a layer which can be laid over a sub-floor with the wire as part of the layer.
  • heating elements are well known and widely used for many different end uses.
  • One end use which is preferred but not the only end use with which the present application is concerned is that of heating tile or other floors where the heating element is located between the sub-floor and the covering material with the floor adhesive applied over the heating element.
  • the element can also be used with other types of covering layer such as concrete.
  • the current limiting device is a simple resistor which can operate satisfactorily.
  • other more complex devices can also be used.
  • This method is particularly applicable in an arrangement in which the first conductor is maintained at or close to a ground potential and an alternating voltage is applied to the second conductor.
  • the alternating voltage can be of the order of 120V or of the order of 240V.
  • the current limiting device is arranged to maintain the current at less that 15mA.
  • the load comprises a heating element defined by a flat sheet having a first surface and a second surface each of which is defined by an insulating material, a first conductor and a second conductor for connection thereacross of an electrical voltage and a conductive material extending between the first and second conductors and located between the first and second surfaces such that the voltage causes a current through the conductive material which generates heat substantially across the full extent of the sheet, wherein the ground conductor comprises a grounding layer laminated to the heating element and comprising a sheet of a conductive foil attached to the first surface of the flat sheet defining the heating element and a covering layer of an electrically insulating plastics material over the foil.
  • the GFCI or GFI systems work on the principle that current entering through the Hot lead will return through the Neutral similar principle and any difference between the currents is indicative of a fault. This is correct both for 120/240 VAC systems. Some new GFCI/GFI devices monitor current on the actual ground lead rather than differences in current flowing between the Hot and Neutral leads.
  • the device can trip a breaker if the current between the Hot and Neutral differs by more than 5 to 15mA depending on the make of GFCI and its classification; up to 500mA for some industrial and equipment protection.
  • These arrangements are provided primarily for fire protection but also are used to prevent shock to persons contacting the equipment.
  • CLD Current Limiting Device
  • the invention concerns a grounding sheet covering the top side of a planar heating mat.
  • the heat mat consist of 2 bus bars separated by resistive elements in turn creating a resistive heating mat.
  • a grounding sheet is laminated over the element separated by a thin plastic sheet. The grounding sheet provides an alternative path to ground for any punctures to the heat mat(s) elements.
  • a current limiting resistor is used to limit current flowing from the grounding sheet. By the use of this current limiting resistor false triggering of the GFCI or GFI as the case may be can be reduced and still have the safety provided by the grounding sheet and the current interrupter.
  • the problem with the induced current is more noticeable triggering the GFCI or GFI as the case may be.
  • the current limiting resistor keeps the current exiting the ground sheet from exceeding the GFCI's fault current (typically 15mA), unless a fault occurs.
  • the problem with the induced current/voltage is more noticeable triggering the RCD (Residual Current Device) used in European systems.
  • the current limiting resistor keeps the current exiting the ground sheet from exceeding the RCD's fault current (typically 30mA).
  • a resistor is the preferred device, however a capacitor/inductor or a combination of the devices can be used as long as the series impedance equals the required value.
  • the heating element comprises:
  • Paper can be used as the material on which the conductors and the printed ink is carried.
  • the conductive strips are printed conductive ink.
  • the first and second layers are polyester.
  • a second sheet of a conductive foil attached to the second surface of the heating element for retarding fire.
  • a reinforcing layer on one side of the heating element which comprises an anti-fracture membrane.
  • the anti-fracture membrane comprises a resilient elastomeric layer.
  • the elastomeric layer is bitumen.
  • the anti-fracture membrane defines a pressure sensitive adhesive surface on an outer surface thereof.
  • the pressure sensitive adhesive layer is covered by a release sheet which can be peeled away to expose the adhesive.
  • the anti-fracture membrane is translucent.
  • the heating element comprises:
  • the contact is one jaw of a clamp which bites through the layers of insulating material to engage the conductor.
  • the first strip is wider than the second strip so as to provide a location to receive an electrical contact of a terminal for connection to a grounding layer.
  • the contact is one jaw of a clamp which bites through the layers of insulating material to engage the grounding layer.
  • a reinforcing layer of a fiber reinforced material defining an outermost layer on the first side of the heating element, the fiber reinforced material defining a fibrous bonding layer for engagement into a tile adhesive layer.
  • the metal foil layer and covering layer of a plastics material are a pre-formed laminate applied as a common laminate onto the sheet forming the heating element.
  • the pre-formed laminate is laminated to the heating element by a laminating layer formed of a plastics sheet carrying on each side a layer of an adhesive.
  • the foil thickness is less than 0.001 inch.
  • a composite heating element 19 comprises a heating element 20 comprising a first flexible electrically insulating plastics layer 21 defining a first surface; a second flexible electrically insulating plastics layer 22 defining a second surface, the layers being connected in overlying relationship to form an elongate sheet with inside surfaces and outside surfaces and overlying side edges as shown in Figure 5 .
  • First and second conductors are defined by respective ones of two continuous electrodes 24 each running along the element between the layers each along a respective one of the side edges and arranged for connection across a supply of a voltage.
  • a conductive material extends between the first and second conductors and located between the first and second surfaces such that the voltage causes a current through the conductive material which generates heat substantially across the full extent of the sheet.
  • the material is defined by a row of conductive strips formed by printed ink layer 26 applied at right angles to the electrodes, contacting the electrodes 24 and 25 thereby setting up parallel electrical heating circuits across the elongate sheet such that the voltage generates a heating current in the strips.
  • a silver layer 27 is applied over the top of the printed ink to generate better contact to the bus bar or electrode 24.
  • a grounding layer 28 is laminated to the heating element by a laminating layer 29 and comprises a sheet of a conductive foil 30 pre-laminated to a covering layer 31 of an electrically insulating plastics material over the foil.
  • the grounding layer 30 is laminated to the first surface 22 of the flat sheet defining the heating element 20 by the laminating layer 29 formed by a layer of plastics material carrying layers of laminating glue.
  • Other laminating methods and materials can be used as known to persons skilled in this art.
  • the first and second conductors 24 and 25 comprise respective ones of two continuous copper electrodes each running along the element between the layers each along a respective one of the side edges and arranged for connection across a supply of a voltage.
  • the first and second layers 21, 22 are polyester.
  • a reinforcing layer 31 on one side 21 which is the lower side of the heating element 20 which comprises an anti-fracture membrane formed of a resilient elastomeric layer such as bitumen.
  • the anti-fracture membrane 32 defines a pressure sensitive adhesive surface 33 on an outer surface thereof which is covered by a release sheet 34 which can be peeled away at 35 to expose the adhesive.
  • the anti-fracture membrane is translucent or at least can be seen through so as to make visible the conductive ink strips 26 so that a user can cut the element to length in a transverse direction while avoiding cutting through the strips 26.
  • a first strip 36 of an electrically insulating material is applied over the first conductor defining a first slot 37 therebetween allowing insertion into the first slot of an electrical contact ( Figure 3 , 4 ) of a first terminal 38;
  • a second strip 40 of an electrically insulating material over the second conductor defining a second slot therebetween allows insertion into the second slot of an electrical contact of a second terminal 39.
  • the slots are formed simply by the expedient of providing no adhesive between the strip and the respective conductor.
  • the contact is one jaw of a clamp which bites through the layers of insulating material to engage into the respective conductor.
  • the strip 36 is wider than the second strip 40 so as to provide a location to receive an electrical contact of a terminal 41 for connection to a grounding layer.
  • the terminals are covered by an insulating cover as is required for electrical insulation of the installation.
  • the contact of the terminal 41 is one jaw of a clamp which bites through the layers of insulating material to engage the foil grounding layer 30.
  • the contact of the terminals 38 and 39 engages downwardly away from the grounding layer, they do not engage the grounding layer.
  • the terminal 41 is spaced along the strip 36 away from the contact 24, it does not engage the strip 24.
  • a reinforcing layer 45 of a fiber reinforced material is laminated by a laminating layer 46 so as to define an outermost layer on the first or upper side of the heating element, the fiber reinforced material defining a fibrous bonding layer for engagement into a tile adhesive layer.
  • the metal foil layer 30 and covering layer 31 of a plastics material are a pre-formed laminate applied as a common laminate onto the sheet forming the heating element with a foil thickness is less than 0.001 inch and preferably of the order of 0.00035 inch.
  • the arrangement uses a thin gage aluminium of thickness only enough to carry the current to keep the costs down.
  • This thin aluminium itself does not have the structural strength (tears/deforms easily) to be easily processed into our laminate structure.
  • the aluminium is already laminated to a polyester carrier sheet that provides all the structural strength for processing.
  • the aluminium is anchored to the polyester using a dry cross-linked polyester based laminating adhesive. This structure is commonly used for shielding telecommunication cables.
  • the polyester on top and the heating element below also act as a barrier films preventing the aluminium from exposure to corrosive elements in all applications.
  • terminal clips 38 and 39 must be attached to the assembly before adding the anti-fracture layer 32.
  • additional strips similar to the strips 36 and 40 are used to provide a similar non adhered spaces or slots similar to the slots previously described but located between the anti-fracture layer 32 and the bottom of the element 26 to attach the terminal clips 38 and 39. This allows the manufacturer to add the anti-fracture layer in line at the same time as other layers like layer 45.
  • the Heating Element comprises a flexible, electrically insulated polyester coated element.
  • the element consists of two electrodes or bus bars running parallel the length of the element.
  • a conductive ink strip is printed onto the polyester at right angles to the electrodes, crossing the electrodes thereby setting up an electrical circuit.
  • the conductive ink is resistive as per desired watts required per square foot (meter). Each bar of ink is calculated in resistance (Ohms) and is part of the heater.
  • the entire element is covered by another electrically insulated polyester film.
  • a third bus bar can be used to carry ground current in the event of a fault, this can be omitted in most circumstances since the current values which generate roughly 10 to 12 watts per square foot which is typical are insufficient to require the additional conductive material and the foil will suffice.
  • the foil may be coated on both sides with a plastics insulating material (not shown) and in the event that the bus bar is not used, it is only necessary to connect to the ground layer at a single point by stripping the plastic coating layer on one side.
  • the bus bar can be located underneath or on top of the foil.
  • the top reinforcing layer of a woven or non-woven scrim can be of the type known as Collbond.
  • the top reinforcing layer of woven or non-woven scrim and the bottom anti-fracture membrane can be used in relation to a wire element type construction where the element is grounded with a grounding sheet or not grounded.
  • the wire of the element is contained in a scrim.
  • a further example includes a grounding layer and includes a second foil layer on the opposed side to the grounding layer for purposes of fire retardance.
  • the anti-fracture membrane may incorporate the heating element as part of the membrane or it may be separately applied depending on the manufacturer.
  • the arrangement can be used in a tiled floor comprising a sub-floor; a layer of tiles applied over the sub-floor; and a heating element where the reinforcing layer of a fiber reinforced material is on the upper side of the heating element and fastened to the layer of tiles by a tile adhesive and the anti-fracture membrane is on the bottom side of the heating element and fastened to the sub-floor.
  • the heating element 100 is defined by a flat sheet 110 having a first surface 111 and a second surface 112 each of which is defined by an insulating material.
  • the insulating material is formed by two layers 101 and 102 of a plastics material which are laminated together as described above. Between the layers 101 and 102 is provide the electrical heating conductors defined by a first conductor 103 and a second conductor 105 for connection thereacross of an electrical voltage and a conductive material 104 extending between the first and second conductors 103, 105 and located between the first and second surfaces 111, 112.
  • the voltage applied causes a current through the conductive material 104 which generates heat substantially across the full extent of the sheet 110.
  • a grounding layer 106, 107 is laminated to the heating element 110 and comprises a sheet of a conductive foil 106 attached to the first surface 112 of the flat sheet 110 defining the heating element 100 and a covering layer 107 of an electrically insulating plastics material over the foil.
  • the arrangement described above can include any or all of the constructions described above including the additional layers and the connections to the conductors.
  • the voltage across the conductors 103, 105 is provided from an AC supply 120 through a ground fault interrupter circuit 121.
  • the circuit 121 is typically provided as a breaker in an electrical supply box with connections 122 and 123 to the AC voltage supply 120. In many cases the connection 122 is held at ground or neutral and the alternating voltage is supplied at the connector 123.
  • a ground connection 125 is connected to a connector 124 of the GFI circuit.
  • the GF! Output provides terminals 127 and 128 which connects the voltage from the supply 120 to the conductors 103 and 105 to generate the heating current.
  • the grounding layer 106 includes a terminal 130 which connects to an input connector 129 of the GFI.
  • the GFI circuit is responsive to current leaking to ground greater than a predetermined set value to switch off the supply of voltage to the connectors 127 and 128.
  • the GFI also includes an over-current sensor to detect current through the connectors 127, 128 greater than a predetermined maximum to switch off the supply voltage.
  • the supply 120 supplies a voltage for generating the heating current across the first and second conductors through a ground fault interrupter having a first terminal connected to the first conductor, a second terminal connected to the second conductor together with a ground terminal connected to the grounding layer and a switch operable in response to a current at the ground terminal greater than a predetermined allowable value;
  • a current limiting device 140 in the form of resistor is connected between the grounding layer 106 and the ground terminal 129 which has a resistance value which reduces current flowing to the ground terminal from the grounding layer caused by current induced on the grounding layer by the heating current to a level less than said predetermined allowable value and which maintains current flowing to the ground terminal from the grounding layer caused by current transmitted to the grounding layer from the heating current due to a fault in the heating element to a level greater than said predetermined allowable value.

Landscapes

  • Surface Heating Bodies (AREA)
  • Central Heating Systems (AREA)
  • Resistance Heating (AREA)
EP11191493A 2010-12-02 2011-12-01 Système de mise à la terre pour la sécurité électrique Withdrawn EP2461643A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA 2724165 CA2724165A1 (fr) 2010-12-02 2010-12-02 Systeme de mise a la terre

Publications (1)

Publication Number Publication Date
EP2461643A1 true EP2461643A1 (fr) 2012-06-06

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EP11191493A Withdrawn EP2461643A1 (fr) 2010-12-02 2011-12-01 Système de mise à la terre pour la sécurité électrique

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EP (1) EP2461643A1 (fr)
CA (1) CA2724165A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111536007A (zh) * 2018-06-08 2020-08-14 杭州启澄科技有限公司 一种降低霍尔推力器热负荷的方法
US10841980B2 (en) 2015-10-19 2020-11-17 Laminaheat Holding Ltd. Laminar heating elements with customized or non-uniform resistance and/or irregular shapes and processes for manufacture
US10925119B2 (en) 2015-01-12 2021-02-16 Laminaheat Holding Ltd. Fabric heating element
USD911038S1 (en) 2019-10-11 2021-02-23 Laminaheat Holding Ltd. Heating element sheet having perforations

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5361183A (en) * 1993-06-30 1994-11-01 Alliedsignal Inc. Ground fault protection for electrothermal de-icing applications
WO2001065891A2 (fr) 2000-03-01 2001-09-07 Calorique, Ltd. Chauffage electrique
WO2005055661A2 (fr) * 2003-12-04 2005-06-16 Iq-Mobil Gmbh Dispositif pour chauffer une surface
DE20321181U1 (de) * 2003-06-03 2006-09-28 Beurer Gmbh & Co Schmiegsames elektrisches Wärmegerät
WO2007008734A2 (fr) 2005-07-12 2007-01-18 Carbonic Heat Corporation Radiateur plat et procede de fabrication
EP1854719A2 (fr) * 2006-05-12 2007-11-14 Goodrich Corporation Panneau de plancher chauffé doté d'un contrôleur intégré et d'un circuit d'interruption en cas de défaut de terre
WO2008063173A1 (fr) 2006-11-21 2008-05-29 Carbonic Heat Corporation Procédé de fabrication d'un dispositif de chauffage plat
US20090266810A1 (en) 2008-04-25 2009-10-29 Edward Chivers Planar heating element for underfloor heating

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5361183A (en) * 1993-06-30 1994-11-01 Alliedsignal Inc. Ground fault protection for electrothermal de-icing applications
WO2001065891A2 (fr) 2000-03-01 2001-09-07 Calorique, Ltd. Chauffage electrique
DE20321181U1 (de) * 2003-06-03 2006-09-28 Beurer Gmbh & Co Schmiegsames elektrisches Wärmegerät
WO2005055661A2 (fr) * 2003-12-04 2005-06-16 Iq-Mobil Gmbh Dispositif pour chauffer une surface
WO2007008734A2 (fr) 2005-07-12 2007-01-18 Carbonic Heat Corporation Radiateur plat et procede de fabrication
EP1854719A2 (fr) * 2006-05-12 2007-11-14 Goodrich Corporation Panneau de plancher chauffé doté d'un contrôleur intégré et d'un circuit d'interruption en cas de défaut de terre
WO2008063173A1 (fr) 2006-11-21 2008-05-29 Carbonic Heat Corporation Procédé de fabrication d'un dispositif de chauffage plat
US20090266810A1 (en) 2008-04-25 2009-10-29 Edward Chivers Planar heating element for underfloor heating
WO2009129595A1 (fr) 2008-04-25 2009-10-29 Alternative Heating Systems Inc. Elément chauffant plan pour chauffage sous plancher

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10925119B2 (en) 2015-01-12 2021-02-16 Laminaheat Holding Ltd. Fabric heating element
US10841980B2 (en) 2015-10-19 2020-11-17 Laminaheat Holding Ltd. Laminar heating elements with customized or non-uniform resistance and/or irregular shapes and processes for manufacture
CN111536007A (zh) * 2018-06-08 2020-08-14 杭州启澄科技有限公司 一种降低霍尔推力器热负荷的方法
USD911038S1 (en) 2019-10-11 2021-02-23 Laminaheat Holding Ltd. Heating element sheet having perforations

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