Method of controlling a ventilation system configured to at least evacuate smoke from a fire

Abstract

Method for controlling a ventilation system (1, 1') allowing smoke from a fire to be evacuated, implementing: A step of closing a contactor (K1); An insulation control step in which a first measuring device (2) measures an image (Id) of a leakage current (If) while at least one phase of a motor (4) of the fan is powered so as to apply a nominal voltage to the at least one phase (U1, U2, U3), and a zero differential voltage of the at least one phase (U1, U2, U3); A step of comparing the image (Id) of the leakage current (If) and a leakage current threshold; A step of controlling the ventilation system (1) Figure 1

Description

Title of the invention: Method for controlling a ventilation system configured to at least evacuate smoke from a fire Technical field

[0001] The invention relates to the field of ventilation systems and more particularly to a method for controlling a ventilation system. State of the prior art

[0002] A ventilation system for a building can have two main roles. On the one hand, in normal situations, it ensures a flow of renewed air in the building in order to maintain air quality, and on the other hand, in a fire situation, it ensures the evacuation of smoke from circulation spaces in order to allow the evacuation of occupants.

[0003] It is known that each of these roles is performed by at least one specific fan. Thus, the ventilation system comprises at least one smoke extraction fan for evacuating fumes and at least one comfort fan to ensure the air renewal flow.

[0004] The smoke extraction fan is stopped in normal conditions but must be able to start at any time. To ensure this, a permanent check of the insulation level of a smoke extraction fan motor is carried out. This makes it possible to detect possible corrosion, infiltration of the motor, etc., causing a current leak and potentially compromising its operation.

[0005] There is a known solution for detecting a leakage current from a motor of a smoke extraction fan when stopped by means of an ohmic measurement in which at least one phase of the motor is supplied with a specific permanent current, generally 12V or 24V, i.e. a current independent of a main electrical supply of the motor.

[0006] The disadvantage of this solution is that it requires a specific electrical insulation test circuit in order to be able to measure the impedance of the coils.

[0007] A second disadvantage is that this solution is only relevant for asynchronous motors, since a simple ohmic measurement is carried out.

[0008] Furthermore, this electrical insulation test circuit does not allow for testing an electrical element that would be positioned between the main power supply and the motor, such as, for example, a frequency converter or a motor controller. In addition, said electrical element prevents the insulation test of the motor coils: This is why a state-of-the-art solution consists of carrying out this test downstream of the frequency converter, by going back through the relay box.

[0009] There is therefore a need for a ventilation system which notably comprises a smoke extraction fan and which makes it possible to ensure insulation control of a fan motor when stopped which is economical, simple and which makes it possible to control all the elements positioned between the main power supply and the motor as well as the motor. Statement of the invention

[0010] One embodiment relates to a method for controlling a ventilation system which comprises a main electrical power supply, at least one motor of a fan, said fan being configured to ensure at least one evacuation of smoke from a fire, the at least one motor comprising at least one electrical phase, at least one contactor having a closed state in which the main electrical power supply is electrically connected to the at least one phase of the motor, at least one first measuring device configured to measure a leakage current positioned between the at least one contactor and the at least one motor, the method implementing: - A step of closing at least one contactor; - An insulation control step in which the at least one first leakage current measuring device measures an image of the leakage current while the at least one phase of the motor is electrically powered by means of the main power supply so as to apply a nominal voltage to the at least one phase, and a zero differential voltage of the at least one phase; - A comparison step in which at least the leakage current image is compared to a leakage current threshold; - A control step in which the ventilation system is controlled based on a result of the comparison step.

[0011] The main power supply corresponds to the power supply of the motor during its normal operation, that is to say when it is rotating. The main power supply preferably has a voltage of 230V or 400V. The main power supply preferably generates an alternating current at 50Hz.

[0012] The fan of the ventilation system provides at least one smoke extraction function during a building fire situation. It is therefore at least one smoke extraction fan whose leakage current must be measured continuously and in particular when it is stopped.

[0013] In certain embodiments, the fan is also configured to ensure air renewal of the building in a normal situation. It is then a comfort fan whose leakage current must be measured when it is in operation.

[0014] Thus, the fan can have a smoke extraction function only or a smoke extraction and comfort function.

[0015] The motor comprises at least one electrical phase, and preferably three. Each electrical phase supplies an electrical coil, which are coupled together in a star or delta connection.

[0016] In some embodiments, the motor is an asynchronous motor.

[0017] In some embodiments, the ventilation system comprises a contactor per electrical phase. Alternatively, the ventilation system includes a contactor for all electrical phases.

[0018] The closing step consists of positioning the contactor in the closed state.

[0019] A common mode voltage is defined as the voltage measured between a part active part of the motor, such as a coil, and an electrical ground.

[0020] A differential voltage is defined as the voltage measured between two active parts of motors, that is to say between two coils.

[0021] The insulation control step consists of electrically supplying the motor via the main power supply, ensuring that at least one phase is at the nominal voltage, and the differential voltage of the at least one phase is zero.

[0022] Thus, at least one phase of the motor is under nominal voltage when searching for the leakage current. This voltage is high enough to guarantee accurate leakage current detection.

[0023] Furthermore, since the differential voltage, i.e. the voltage difference across the phase coil, is zero, the motor is not set into rotation.

[0024] The first measuring device is configured to measure an image of a leakage current. It is a device measuring an electric current of the ammeter type.

[0025] The first measuring device therefore detects a current leak, which may come from an insulation fault, across the entire electrical circuit downstream of the measurement.

[0026] The comparison step makes it possible to compare the leakage current with a leakage current threshold so as to determine whether the electrical circuit downstream of the measurement has an insulation fault.

[0027] Finally, the control step makes it possible to adapt the operation of the ventilation system based on the result of the comparison step.

[0028] The invention thus makes it possible to measure and detect, when the motor is stopped, an insulation fault.

[0029] The subject matter of the present disclosure may also have one or more of the following characteristics taken alone or in combination.

[0030] In some embodiments, the method comprises an insulation monitoring step in which the at least one first measuring device measures the leakage current image while the at least one phase of the motor is electrically powered by means of the main power supply so that the motor is in normal operation.

[0031] The first measuring device therefore also measures the image of the leakage current when the motor is in operation, i.e. when it is rotating.

[0032] Thus, the detection of an insulation fault is carried out continuously: whether the motor is stopped or rotating.

[0033] In some embodiments, controlling the ventilation system is positioning the at least one contactor in an open state in which the main power supply is electrically separated from the at least one phase of the motor, and / or issuing an alarm.

[0034] When the leakage current is higher than the leakage current threshold, an insulation fault is present in the installation. A command from the ventilation system can then be to position the contactor in the open state. Thus, the motor is no longer powered and there is no longer any risk of electrocution.

[0035] Furthermore, the command can also be the emission of an alarm. An alarm is any signal indicating that the ventilation system has a problem. The alarm can be visual, audible, haptic or information transmitted to a controller of a control center monitoring fire protection systems, for example by means of an electric wire. In this way, the ventilation system indicates that a fault is present.

[0036] In some embodiments, the ventilation system comprises a variable frequency drive positioned between the at least one first measuring device and the at least one motor.

[0037] A power supply frequency can vary thanks to a frequency converter allowing pulse width modulation (PWM) also called Pulse Width Modulation to adapt to the needs of the installation.

[0038] In some embodiments, the motor is an electronically commutated motor and the ventilation system comprises a controller of said motor, said controller being positioned between the at least one first measuring device and the at least one motor.

[0039] The motor controller allows modulating by means of pulse width modulation (PWM) also called PWM for Pulse Width Modulation, the voltage and therefore a rotation speed of the fan motor and therefore ultimately a ventilation flow rate.

[0040] The advantage of being able to vary the ventilation flow rate on a smoke extraction fan, and therefore the depression created in a building in which the ventilation system is installed, is to be able to adapt the flow rate of the fan in smoke extraction mode to a specific floor of the building. In this way, the depression created in the floor is adapted and does not require the installation of additional means of regulating pressure losses at the levels of the smoke extraction hatches, for example. In addition, since the flow rate is adapted to the floor, there is no risk of destratification of the fumes.

[0041] Furthermore, the advantage of being able to vary the ventilation flow rate on a comfort fan is that it allows the ventilation flow rate to be adapted to the number of people present in the building and / or to the activities carried out, such as use of the toilets for example.

[0042] Finally, the use of a frequency converter or an electronically commutated motor makes it possible to reduce the level of energy consumption of the motor.

[0043] Thus, the invention makes it possible, for example, to use the fan as a comfort fan while allowing permanent monitoring of the leakage current, which also makes it possible to use the same fan as a smoke extraction fan.

[0044] In some embodiments, the motor comprises a plurality of phases, the insulation monitoring step being performed while at least two phases of the motor are each electrically supplied with a current in phase with each other.

[0045] In this embodiment, the motor comprises at least two phases, the zero differential voltage between the two phases is obtained by supplying each phase with a current in phase with each other. The insulation control step then consists of measuring the overall leakage current of the phases.

[0046] Another way of carrying out the insulation control step between coils consists of measuring the differential leakage current between two phases of the motor. For this, only one phase of the motor is supplied with the nominal current, the other phases not being electrically supplied: the measurement of the insulation current is made between two coils. The operation must be repeated as many times as there are combinations between coils on a three-phase motor and it is checked that each combination offers an identical insulation current measurement.

[0047] In some embodiments, the method also comprises an electrical control step in which a continuity current is measured while the at least one phase of the motor is electrically powered by means of the main power supply so as to apply a non-zero differential voltage to the at least one phase of the motor. at least one phase, said differential voltage not allowing said motor to rotate.

[0048] The control step makes it possible to detect a continuity current representative of a continuity fault in the electrical circuit downstream of the measurement carried out, such as a short circuit, a cut or disconnected wire.

[0049] The control step makes it possible to detect an imbalance of the phases, and the integrity of each of the coils.

[0050] The differential voltage seen by the phase is chosen so as not to allow the motor to start.

[0051] The control step is performed between the closing step and the comparison step.

[0052] The comparison step then also compares the continuity current to a threshold continuity. The comparison stage then emits a fault signal when at least the continuity threshold or the leakage current threshold is exceeded.

[0053] In some embodiments, the continuity current is measured by the first measuring device.

[0054] In some embodiments, the continuity current is measured by the motor controller or drive.

[0055] In some embodiments, the comparison step compares the at least one continuity current, respectively the at least one image of the leakage current, with at least one previously measured continuity current, respectively the at least one image of the previously measured leakage current.

[0056] The comparison step then makes it possible to monitor the general evolution over time of the continuity current and / or the leakage current in order to detect and prevent any premature aging.

[0057] The measurements of the continuity currents and / or the leakage current are stored so that at each new measurement, the new measurement, i.e. the current measurement, is compared to at least one stored measurement, both for an overall value of the motor corresponding to the leakage current and for each of the coils corresponding to the continuity current.

[0058] In some embodiments, the leakage current threshold is modified depending on an operating situation of a building in which the ventilation system is installed.

[0059] Several operating situations of the building are distinguished, including a fire situation, in which at least one piece of information about the presence of a fire in the building is emitted, and a normal situation in which no information about the presence of a fire is emitted.

[0060] According to the invention, the leakage current threshold is modified depending on the operating situation of the building. Thus, it is possible to adapt the threshold from which An electrical fault is detected by the ventilation system. In this way, when the fan is operating as a comfort fan, the leakage current threshold is adapted to protect people. For this purpose, the leakage current threshold can, for example, be set to 30 mA.

[0061] When the fan is stopped or operating as a smoke extraction fan, the leakage current threshold can be removed in order to operate the fan without stopping.

[0062] In some embodiments, the continuity threshold is modified depending on an operating situation of the building in which the ventilation system is installed.

[0063] In some embodiments, the ventilation system receives data relating to the operating situation of the building by means of at least one dry contact, at least one analog signal, or at least one digital bus.

[0064] The operating situation of the building is generally determined by a fire controller which transmits this information to the ventilation system according to the invention and more particularly to a main controller of the ventilation system which may have the form of a relay box.

[0065] In some embodiments, the at least one first leakage current measuring device comprises a self-monitoring device.

[0066] Thus the first measuring device analyses its proper functioning.

[0067] Another aspect of the invention relates to a ventilation system implementing a method according to the invention. Brief description of the drawings

[0068] The invention will be better understood, thanks to the following description, which relates to several embodiments according to the present invention, given as non-limiting examples and explained with reference to the appended schematic drawings, in which:

[0069] [Fig. 1] is a schematic representation of a first embodiment of a ventilation system according to the invention;

[0070] [Fig.2] is a schematic representation of a second embodiment of a ventilation system according to the invention;

[0071] [Fig.3] is a representation of the supply voltages of each phase of a motor during the insulation control step;

[0072] [Fig.4] is a representation of the supply voltages of each phase of the motor during normal supply. Description of the embodiments

[0073] Only the elements necessary for understanding the invention have been shown. To facilitate reading of the drawings, the same elements bear the same references from one figure to another.

[0074] Figures 1 and 2 show a ventilation system 1,1' according to two embodiments of the invention. Said ventilation systems 1,1' are configured to be positioned in a building. In the remainder of the description, reference is made only to a single ventilation system, however, unless otherwise stated, the characteristics relate to both embodiments.

[0075] Several operating situations of said building are distinguished, including a fire situation, in which at least one piece of information C; of the presence of a fire in the building is emitted, and a normal situation in which no information of the presence of a fire is emitted. The operating situation of the building is generally determined by a fire controller Fi which transmits this information to the ventilation system 1, 1' and more particularly to a main controller F2 of the ventilation system 1, 1'.

[0076] Said ventilation system 1,1' comprises a main power supply 7 which corresponds to the power supply of the ventilation system 1,1' during its normal operation, that is to say when it is put into operation and more particularly when a fan 3 of the ventilation system 1,1' is put into operation. The main power supply 7 preferably has a voltage of 230V. The main power supply 7 preferably generates an alternating current at 50Hz.

[0077] Said ventilation system 1,1' comprises a motor 4 of a fan 3. The fan 3 provides at least one smoke extraction function during a fire situation in the building. It is therefore at least one smoke extraction fan for which a leakage current If, or at least an ohmic resistance of the coils, must be measured continuously and in particular when it is stopped in order to guarantee its proper operation.

[0078] In certain embodiments, the fan 3 is also configured to ensure air renewal of the building in the normal situation. It is then a comfort fan whose leakage current If must be measured when it is in operation.

[0079] Thus, the fan 3 can have a smoke extraction function only, or smoke extraction and comfort.

[0080] The motor 4 of the fan 3 comprises at least one electrical phase, and preferably three phases Ul, U2, U3 as illustrated in [Fig.l] and 2. Each electrical phase Ul, U2, U3 supplies an electrical coil, which are coupled together in a star or delta connection. [Fig.4] illustrates a schematic representation of the supply voltages of each phase Ul, U2, U3 of motor 4 during normal power supply.

[0081] In certain embodiments, illustrated in [Fig.l] and 2, the motor 4 is an asynchronous motor. In this case and as illustrated in [Fig.l], said ventilation system 1 preferably comprises a frequency converter 6 positioned between a first measuring device 2 and the motor 4. Alternatively, and as illustrated in [Fig.2], the asynchronous motor is directly connected to the first measuring device 2.

[0082] Alternatively, and as illustrated in [Fig.l], the motor 4 is an electronically commutated motor and the ventilation system 1 comprises a controller 6 of said motor 4, said controller 6' being positioned between the first measuring device 2 and the motor 4.

[0083] The frequency converter 6 or the controller 6' comprises a rectifier and an inverter which is provided with switching cells Q1, Q2, Q3, Q4, Q5, Q6 so as to supply, from the main power supply 7, each phase of the motor 4.

[0084] The frequency converter 6 or the controller 6' make it possible to modulate by means of pulse width modulation (PWM) also called Pulse Width Modulation, the voltage and therefore a rotation speed of the motor 4 of the fan 3 and therefore ultimately a ventilation flow rate.

[0085] The frequency converter 6 or the controller 6' exchanges control information Ct bidirectionally with a main controller F2 of the ventilation system 1. The control information Ct makes it possible to control and modify the phase currents of the motor 4 so as to start it, modify its speed, or stop it.

[0086] Said ventilation system 1,1' comprises at least one contactor Kl which has a closed state in which the main electrical supply 7 is electrically connected to at least one phase of the motor 4, and an open state in which the main electrical supply is electrically separated from the at least one phase of the motor 4. The contactor Kl receives an opening or closing order Co / f making it possible to modify its state.

[0087] In certain embodiments, the ventilation system 1, 1' comprises a contactor per electrical phase. Alternatively and as illustrated in Figures 1 and 2, the ventilation system 1, 1' comprises a contactor K1 for all the electrical phases.

[0088] Said ventilation system 1,1' also comprises a first measuring device 2 positioned between the contactor K1 and the motor 4, the first measuring device 2 is a device measuring an electric current of the ammeter type. The first measuring device 2 detects a current leak If, which may come from a insulation fault, on the entire electrical circuit downstream of the measurement, i.e. between the first measuring device 2 and the fan 3.

[0089] In the embodiment of [Fig.2], the first measuring device 2 can also detect a continuity current Ic. In the embodiment of [Fig.l], the continuity current Ic is detected by.

[0090] The continuity current Ic may come from a continuity fault, such as a short circuit, a cut or disconnected wire, on the entire electrical circuit downstream of the measurement, i.e. between the first measuring device 2 or between the controller 6 or the frequency converter 6', and the fan 3.

[0091] According to one embodiment, the at least one first measuring device 2 comprises a self-monitoring device. Thus the first measuring device analyzes its proper functioning.

[0092] The ventilation system 1,1' comprises the main controller F2 which controls an operation of the ventilation system 1,1'. The main controller F2 may be a relay box, i.e. an Actuated Safety Device (ASD) used in a fire protection system to control the smoke extraction fans.

[0093] The main controller F2 receives at least signals from the first measuring device 2 2 such as the image Id of the leakage current If and in certain cases the continuity current Ie, issues the opening or closing order Co / f to the contactor Kl, and exchanges control information Ct with the frequency converter 6 or the controller 6'. The main controller F2 also receives comfort commands Cc from a comfort control system Fc. These comfort commands Cc may be, for example, an operating situation of the building and more particularly a normal situation, an operating request, a flow level, a requested pressure, etc.

[0094] The main controller F2 also receives fire commands Ci from a fire controller Fi. These fire commands Q may be, for example, data relating to the operating situation of the building and more particularly a fire situation, a floor of the building where the fire is located, etc. The fire commands C; may be received by means of at least one dry contact, at least one analog signal, or at least one digital bus.

[0095] The main controller F2 emits at least one fault signal, also called alarm AA in the remainder of the description, to the fire controller Fi. The alarm AA indicates a malfunction of the ventilation system 1. An alarm AA is any signal indicating that the ventilation system has a problem. The alarm AA can be visual, audible, haptic or information transmitted to the fire controller Fi, for example by means of an electric wire. In this way, ventilation system 1 indicates that a fault is present.

[0096] The ventilation system 1,1' implements a control method which comprises a step of closing the at least one contactor K1. This step consists of positioning the contactor K1 in the closed state.

[0097] The method also comprises an insulation control step in which the at least one first measuring device 2 measures the image Id of the leakage current If while the at least one phase of the motor 4 is electrically powered by means of the main power supply 7 and so as to apply a nominal voltage to the at least one phase, and a zero differential voltage of the at least one phase. In other words, the insulation control step consists of electrically powering the motor 4 by the main power supply 7 while ensuring that the at least one phase Ul, U2, U3 is at the nominal voltage, and the differential voltage of the at least one phase is zero.

[0098] Thus, the at least one phase of the motor 4 is under nominal voltage when searching for the leakage current If. This voltage is sufficiently high to guarantee accurate leakage current detection If. Furthermore, since the differential voltage, i.e. the voltage difference across the terminals of the phase coil, is zero, the motor 4 is not rotated.

[0099] This type of leakage current measurement If is therefore particularly suitable for smoke extraction fans which are normally stopped.

[0100] For many motors, a single phase supply is sufficient, since the coils are very frequently connected together.

[0101] In Figures 1 and 2, the motor 4 comprises three phases. Thus, the insulation control step can be carried out in several ways, one of which consists of supplying at least two phases of the motor 4 with an electric current in phase with each other and then checking that the images Ie of the leakage currents If are identical for each phase pair configuration. For this, two phases of the motor are supplied with the nominal current in phase with each other and the third phase with a nominal current out of phase. The operation must be repeated as many times as there are combinations between coils on a three-phase motor. Alternatively and as illustrated in [Fig.3], all phases Ul, U2, U3 of the motor 4 are supplied and a single leakage current measurement If is carried out.

[0102] In certain embodiments, the first measuring device 2 also measures the image Ic of the leakage current If when the motor 4 is in operation.

[0103] The method also comprises an electrical control step in which the continuity current 1c is measured while the at least one phase of the motor 4 is electrically powered by means of the main power supply 7 so as to apply a non-zero differential voltage to the at least one phase, said differential voltage not allowing said motor 4 to rotate.

[0104] The differential voltage seen by the phase of motor 4 is chosen so as not to allow motor 4 to start. Thus, the electrical control step is suitable for smoke extraction fans which are normally stopped.

[0105] The electrical control step is carried out between the closing step and the comparison step, before or after the insulation control step.

[0106] Then the method comprises a comparison step in which at least the image Id of the leakage current If is compared to a leakage current threshold so as to determine whether the electrical circuit downstream of the measurement has an insulation fault.

[0107] The comparison step can also compare the continuity current Ic to a continuity threshold.

[0108] The comparison step determines that the ventilation system 1, 1' comprises an insulation and / or continuity fault when at least the continuity threshold or the leakage current threshold is exceeded, i.e. when the image Id of the leakage current If is greater than the leakage current threshold or when the continuity current Lest is greater than the continuity threshold.

[0109] According to the invention, the leakage current threshold and / or the continuity threshold is modified depending on the operating situation of the building. Thus, it is possible to adapt the threshold from which an electrical fault is detected by the ventilation system 1. In this way, when the fan 3 operates as a comfort fan, the leakage current threshold is adapted for protection of persons. For this purpose, the leakage current threshold can for example be set to 30mA.

[0110] When the fan is stopped or operating as a smoke extraction fan, the leakage current threshold and / or the continuity threshold can be suppressed in order to operate the fan without stopping.

[0111] In certain embodiments, the comparison step compares the continuity current L respectively the image L of the leakage current If, with at least one continuity current Ic previously measured, respectively the at least one image Id of the leakage current If previously measured.

[0112] The comparison step then makes it possible to monitor the general evolution over time of the continuity current Ic and / or the leakage current If in order to detect and prevent any premature aging.

[0113] The measurements of the continuity currents L and / or the leakage current If are stored so that at each new measurement, the new measurement, i.e. the current measurement, is compared to at least one stored measurement and this also for a overall value of the motor 4 corresponding to the leakage current as for each of the coils corresponding to the continuity current.

[0114] Finally, the method comprises a control step which makes it possible to adapt an operation of the ventilation system 1, 1' as a function of the result of the comparison step, that is to say as a function of the presence of an insulation or continuity fault.

[0115] The command may be a positioning of the contactor K1 in the open state. Thus, the motor 4 is no longer powered and there is no longer any risk of electrocution. This command is used when the fan 3 is used when the building is in a normal situation, that is to say when the fan is used as a comfort fan. This command is preferably accompanied by the emission of an AA alarm.

[0116] The command can also be the emission of the AA alarm alone. This command is used when the fan 3 is used when the building is in a fire situation, that is to say when the fan is used as a smoke extraction fan.

[0117] The invention thus makes it possible to measure and detect, when the motor 4 is stopped, an insulation and / or continuity fault by means of the main electrical power supply 7.

[0118] In addition, the frequency converter or the electronically commutated motor controller allows the ventilation flow rate to be varied. On a smoke extraction fan, it is thus possible to adapt the depression created in the building to the specific floor of the building where the fire is present. In this way, the depression created in the floor is adapted and does not require the installation of additional means of regulating pressure losses at the levels of the smoke extraction hatches, for example. In addition, since the flow rate is adapted to the floor, there is no risk of destratification of the smoke.

[0119] Furthermore, the advantage of being able to vary the ventilation flow rate on a comfort fan is that it allows the ventilation flow rate to be adapted to the number of people present in the building and / or to the activities carried out, such as use of the toilets for example.

[0120] Finally, the use of a frequency converter 6 or an electronically commutated motor makes it possible to reduce the level of energy consumption of the motor.

[0121] Thus, the invention makes it possible, for example, to use the fan 4 as a comfort fan while allowing permanent control of the insulation current, which also makes it possible to use the same fan 4 as a smoke extraction fan.

[0122] Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0123] It is also obvious that all the characteristics described with reference to a method are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a method.

Claims

Claims

1. Method for controlling a ventilation system (1, 1') which comprises a main power supply (7), at least one motor (4) of a fan (3), said fan (3) being configured to ensure at least one evacuation of smoke from a fire, the at least one motor (4) comprising at least one electrical phase (Ul, U2, U3), at least one contactor (Kl) having a closed state in which the main power supply (7) is electrically connected to the at least one phase of the motor (4), at least one first measuring device (2) configured to measure a leakage current (If) positioned between the at least one contactor (Kl) and the at least one motor (4), the method implementing: - A step of closing the at least one contactor (Kl);- An insulation control step in which the at least one first measuring device (2) measures an image (Id) of the leakage current (If) while the at least one phase of the motor (4) is electrically powered by means of the main power supply (7) so as to apply a nominal voltage to the at least one phase (Ul, U2, U3), and a zero differential voltage of the at least one phase (Ul, U2, U3); - A comparison step in which at least the image (Id) of the leakage current (If) is compared with a leakage current threshold; - A control step in which the ventilation system (1) is controlled according to a result of the comparison step.;

2. Method according to claim 1, wherein the control of the ventilation system (1) is a positioning of the at least one contactor (Kl) in an open state in which the main power supply (7) is electrically separated from the at least one phase (Ul, U2, U3) of the motor (4), and / or an emission of an alarm (AA).

3. A method according to any preceding claim, wherein the ventilation system (1) comprises a frequency converter (6) positioned between the at least one first measuring device (2) and the at least one motor (4).

4. Method according to any one of claims 1 to 2, wherein the motor (4) is an electronically commutated motor and the ventilation system (1) comprises a controller (6') of said motor (4), said controller (6') being positioned between the at least one first measuring device (2) and the at least one motor (4).

5. A method according to any one of claims 3 or 4, wherein the motor (4) comprises a plurality of phases (U1, U2, U3), the insulation monitoring step being carried out while at least two phases of the motor (4) are each electrically supplied with a current in phase with each other.

6. Method according to any one of claims 3 to 5, also comprising an electrical control step in which a continuity current (Ic) is measured while the at least one phase of the motor (4) is electrically supplied by means of the main power supply (7) so as to apply a non-zero differential voltage to the at least one phase, said differential voltage not allowing said motor (4) to rotate.

7. Method according to claim 6, wherein the comparison step compares the at least one continuity current (Ie), respectively the at least one image of the leakage current, with a previously measured continuity current, respectively the at least one image of the previously measured leakage current.

8. A method according to any preceding claim, wherein the leakage current threshold is changed depending on an operating situation of a building in which the ventilation system (1) is installed.

9. Method according to claim 8, in which the ventilation system receives data relating (Cc, Ci) to the operating situation of the building by means of at least one dry contact, at least one analog signal, or at least one digital bus.

10. Method according to any one of the preceding claims, wherein the at least one first measuring device (2) comprises a self-monitoring device.

11. Ventilation system (1) implementing a method according to any one of the preceding claims.

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