CN203707750U - Phase failure protective device - Google Patents

Abstract

Disclosed is a phase failure protective device. The device comprises a control loop, a phase failure monitor loop, an intermediate relay 1ZJ control circuit, an intermediate relay 2ZJ control circuit, and a magnetic starter C control circuit. The intermediate relay 1ZJ control circuit is connected to one phase of a main circuit of a cooling motor. The device further comprises a manual start button IITA, an intermediate relay 1ZJ coil, a manual start button QA1, an electric contact thermometer ITWJ1, a normally open contact 1ZJ1 controlled by an intermediate relay 1ZJ, a electric contact thermometer IITWJ2, a normally closed contact 1ZJ2 controlled by the intermediate relay 1ZJ, and a changeover switch QK. The manual start button QA1, the electric contact thermometer ITWJ1, and the normally open contact 1ZJ1 controlled by the intermediate relay 1ZJ are in parallel connection. The electric contact thermometer IITWJ2 and the normally closed contact 1ZJ2 controlled by the intermediate relay 1ZJ are in parallel connection. The manual start button IITA, a manual start button IQA, the electric contact thermometer IITWJ2, the changeover switch QK, and the intermediate relay coil 1ZJ are in series connection. The phase failure protective device is simple in structure, convenient in installation and usage, and suitable for phase failure protection of four or more three-phase asynchronous motors.

Description

A kind of open phase protection

Technical field

The utility model relates to cooling tower technical field, especially relates to a kind of circulation-water pump electric machine group's used for cooling tower open phase protection.

Background technology

Open phase protection be rely on current vanishes in a phase conductor of polyphase circuit and disconnect protected equipment or rely on polyphase system one mutually or a few phase decompression to prevent that power supply is applied to a kind of protected mode on protected equipment.Common open phase protection is made up of control loop and disconnected phase monitoring circuit; when disconnected phase time occurs motor; disconnected phase monitoring circuit can make to move post sound system and sound, carries out sound and light alarm action, and can be used for control loop automatic cut-off power, and protection motor is not burned.In fuel gas-steam generation engineering; general supporting more than two cooling tower; many cooling fans are installed on every cooling tower; according to the setting of above-mentioned open phase protection; the three phase electric machine of every cooling fan all needs to install a set of independent open phase protection, and this design cost is high, floor space is large.

Summary of the invention

The purpose of this utility model is to overcome the shortcoming existing in prior art, a kind of Cooling Towers open phase protection is provided, this device connects according to star the principle that asterism voltage raises after a threephase asynchronous phase power-off in service and reaches the object of controlling protection, the technical scheme adopting is: a kind of open phase protection, comprise control loop and disconnected phase monitoring circuit, it is characterized in that: described control loop comprises auxiliary relay 1ZJ control circuit, auxiliary relay 2ZJ control circuit and magnetic starter C control circuit, auxiliary relay 1ZJ control circuit is connected to wherein going up mutually of a cooling motor main circuit, comprise manual actuation of button II TA and auxiliary relay 1ZJ coil, also comprise the manual actuation of button QA I being connected in parallel, the contact 1ZJ1 open in usual of electric contact thermometer I TWJ1 and auxiliary relay 1ZJ, also comprise the normally closed type contact 1ZJ2 that the electric contact thermometer II TWJ2 that is connected in parallel and auxiliary relay 1ZJ control, also comprise diverter switch QK, described manual actuation of button II TA, manual actuation of button I QA, electric contact thermometer II TWJ2, diverter switch QK and auxiliary relay coil 1ZJ are cascaded, auxiliary relay 2ZJ control circuit comprises the motor phase failure signal relay XJ contact open in usual and the auxiliary relay 2ZJ control coil that are cascaded, magnetic starter C control circuit comprises the contact open in usual of the auxiliary relay 1ZJ being cascaded, normally closed type contact and the magnetic starter C control coil of magnetic latching relay RJ, and all the other two are connected magnetic starter C control circuit and cooling motor main circuit, described disconnected phase monitoring circuit comprises separate unit motor phase failure monitoring circuit, every separate unit motor phase failure monitoring circuit comprises rectifier diode ZD, the light-emitting diode GD and many voltage stabilizing didoe WD, current-limiting resistance XLD and the motor phase failure signal relay coil XJ that cooling motor is shared that are connected to separate unit cooling motor asterism, on motor phase failure signal relay coil, be also parallel with fly-wheel diode XD, more than two separate unit motor phase failure monitoring circuit is connected in parallel.

Technical characterictic of the present utility model also has: control loop is connected between the fuse RD and magnetic latching relay RJ of cooling motor main circuit.

Technical characterictic of the present utility model also has: disconnected phase monitoring circuit is connected between the magnetic latching relay RJ and fuse 1RD of cooling motor main circuit.

The beneficial effects of the utility model are: the utility model is simple in structure, install and use facility, be applicable to 4 and above threephase asynchronous group's open phase protection.

Brief description of the drawings

Accompanying drawing 1 is the utility model structural representation, wherein, C is magnetic starter, 1ZJ is auxiliary relay I, 2ZJ is auxiliary relay II, TWJ1 is electric contact thermometer I, TWJ2 is electric contact thermometer II, QA is manual actuation of button I, TA is manual actuation of button II, QK is diverter switch, 1ZD is rectifier diode, 1GD is light-emitting diode, WD is voltage stabilizing didoe, XJ is signal relay, XLD is current-limiting resistance, XJ is motor phase failure signal relay, XD is fly-wheel diode, DK is mains switch, RD is fuse, 1 RD is fuse, 1D is cooling motor coil, RJ is magnetic latching relay.

Embodiment

Below in conjunction with accompanying drawing, embodiment of the present utility model is described.The utility model discloses a kind of open phase protection, this open phase protection connects according to star the principle that asterism voltage raises after a threephase asynchronous phase power-off in service and designs, and has realized the phase failure protection function of a cooling motor group of planes.This protective device comprises control loop and disconnected phase monitoring circuit, control circuit can be according to the automatic start-stop cooling motor of the variation of cooling column water temperature, in the time there is open phase fault in cooling motor, disconnected phase monitoring circuit can make to move post sound system and sound, and sound and light alarm, and can be used for the disconnected phase power supply of control loop automatic switchover, protection cooling motor is not burned, the power line of last cooling motor power line and First cooling motor is connected in parallel, it is looping supply line, in the time that in annular electric supply circuit, a place breaks, can avoid cooling motor phase-deficient operation.

Concrete structure is: the control loop of this device comprises auxiliary relay 1ZJ control circuit, auxiliary relay 2ZJ control circuit and magnetic starter C control circuit, auxiliary relay 1ZJ control circuit is connected to one of a cooling motor main circuit and goes up mutually, comprise manual actuation of button II TA and auxiliary relay 1ZJ coil, also comprise the manual actuation of button I QA being connected in parallel, the contact 1ZJ1 open in usual of electric contact thermometer I TWJ1 and auxiliary relay 1ZJ, also comprise the normally closed type contact 1ZJ2 that the electric contact thermometer II TWJ2 that is connected in parallel and auxiliary relay 1ZJ control, also comprise and there are two selectable diverter switch QK of state.Manual actuation of button II TA, manual actuation of button I QA, electric contact thermometer II TWJ2, diverter switch QK and auxiliary relay coil 1ZJ are cascaded.Auxiliary relay 2ZJ control circuit comprises the motor phase failure signal relay XJ contact open in usual and the auxiliary relay 2ZJ control coil that are cascaded; Magnetic starter C control circuit comprises the contact open in usual of the auxiliary relay 1ZJ being cascaded, normally closed type contact and the magnetic starter C control coil of magnetic latching relay RJ, and all the other two are connected magnetic starter C control circuit and cooling motor main circuit.Disconnected phase monitoring circuit comprises separate unit motor phase failure monitoring circuit, every separate unit motor phase failure monitoring circuit comprises rectifier diode ZD, the light-emitting diode GD and many voltage stabilizing didoe WD, current-limiting resistance XLD and the signal relay coil XJ that cooling motor is shared that are connected to separate unit cooling motor asterism, on signal relay coil, be also parallel with fly-wheel diode XD, more than two separate unit motor phase failure monitoring circuit is connected in parallel.

Operation principle: the control loop of cooling tower cooling motor is made up of electrical equipment such as magnetic starter C, auxiliary relay 1ZJ and 2ZJ, electric contact thermometer TWJ and buttons.In the time that cooling column water temperature reaches cooling fan cranking temperature (being generally 30～40 DEG C), electric contact thermometer I TWJ1 electricity is connected, auxiliary relay 1ZJ obtains electric adhesive, and self-sustaining, the contact open in usual 1ZJ3 closure of auxiliary relay 1ZJ makes magnetic starter C adhesive, and 4 cooling motors turn round simultaneously.Due to the cooling effect of cooling fan, cooling column water temperature declines, in the time that water temperature drops to fan electromotor and stops below temperature (25～20 DEG C), electric contact thermometer TWJ2 contact disconnects, auxiliary relay coil 1ZJ dead electricity, the contact 1ZJ3 open in usual of auxiliary relay control disconnects, magnetic starter C dead electricity, 4 cooling motors stop, and circuit recovers original state.When oil temperature is increased to adjusting when temperature of electric contact thermometer I TWJ1 again, circuit repeats said process, and cooling column water temperature is no more than the electric contact thermometer I TWJ1 temperature of adjusting all the time.When the effect of manual actuation of button I QA, manual actuation of button II TA is the temperature of cooling column water temperature between electric contact thermometer I TWJ1～electric contact thermometer II TWJ2, manually start-stop cooling motor.

Disconnected phase monitoring circuit is made up of rectifier diode ZD, the light-emitting diode GD and 4 the shared elements such as voltage stabilizing didoe WD, signal relay XJ, current-limiting resistance XLD of cooling motor that are connected on motor asterism.In the time that motor normally moves, asterism voltage equals null value in theory, but because motor triphase parameter and three phase mains are not absolute equilibrium, make asterism there is low voltage, the direct voltage that this voltage obtains after halfwave rectifier is less than the reverse breakdown voltage (burning voltage) of voltage-stabiliser tube, and voltage-stabiliser tube is in reverse blocking state, and signal relay coil no current flows through, light-emitting diode is not luminous, signal relay be failure to actuate cooling motor keep run well.If when wherein one or several motors lack a phase power supply, when this motor action asterism voltage raises, rectification output dc voltage is greater than the burning voltage of voltage-stabiliser tube, voltage-stabiliser tube is breakdown, corresponding lumination of light emitting diode, signal relay action, contact point signal relay XJ action, it is electric that the contact point signal relay XJ closing of contact open in usual of its control obtains auxiliary relay 2ZJ, the contact 2ZJ2 open in usual that auxiliary relay 2ZJ controls has connected " cooling tower fault " alarm window loop, the electric bell warning that pipes.Operations staff can, according to the instruction of alarm window (cooling tower fault), signal relay (cooling motor phase shortage) and light-emitting diode (position of diverter switch QK in signal "×"), can judge rapidly the cooling motor of phase shortage and process.If QK is in the time of tripping operation " T " position, except Normal Alarm, 2ZJ1 makes 1ZJ dead electricity, and 1ZJ3 makes C dead electricity, and 4 motors shut down.Now, in order to judge that phase shortage motor can be placed in QK " X " position, involution XJ resets cooling motor, observes light-emitting diode, determines after phase shortage motor, shuts down and processes.

In the time that cooling motor phase shortage is started, UN0 is 110V, and disconnected phase monitoring circuit electric current is large, for fear of damaging diode and signal relay, sealed in loop have nonlinear characteristic current-limiting resistance-incandescent lamp bulb XLD of (electric current hour resistance is little).In order to reduce current impulse, the two ends parallel connection of motor phase failure signal relay XJ coil fly-wheel diode XD.

In control loop, magnetic starter C coil power (380V) is taken from AB phase, and auxiliary relay 1ZJ coil power (220V) is taken from C phase, and in the time of power bus phase shortage, circuit can refuse to start cooling motor; In electric power loop below magnetic starter C; the power line of the 4th motor and the power line of First motor are connected in parallel, i.e. looping supply line, when place when broken string occurs on toroid; can avoid cooling motor phase-deficient operation, realize the open phase protection of a cooling electric group of planes.

Certainly; above-mentioned explanation is not limitation of the utility model; the utility model is also not limited only to above-mentioned giving an example, and variation, remodeling, interpolation or replacement that those skilled in the art make in essential scope of the present utility model, also belong to protection range of the present utility model.

Claims (3)

1. an open phase protection, comprise control loop and disconnected phase monitoring circuit, it is characterized in that: described control loop comprises auxiliary relay 1ZJ control circuit, auxiliary relay 2ZJ control circuit and magnetic starter C control circuit, auxiliary relay 1ZJ control circuit is connected to wherein going up mutually of a cooling motor main circuit, comprise manual actuation of button II TA and auxiliary relay 1ZJ coil, also comprise the manual actuation of button QA I being connected in parallel, the contact 1ZJ1 open in usual of electric contact thermometer I TWJ1 and auxiliary relay 1ZJ, also comprise the normally closed type contact 1ZJ2 that the electric contact thermometer II TWJ2 that is connected in parallel and auxiliary relay 1ZJ control, also comprise diverter switch QK, described manual actuation of button II TA, manual actuation of button I QA, electric contact thermometer II TWJ2, diverter switch QK and auxiliary relay coil 1ZJ are cascaded, auxiliary relay 2ZJ control circuit comprises the motor phase failure signal relay XJ contact open in usual and the auxiliary relay 2ZJ control coil that are cascaded, magnetic starter C control circuit comprises the contact open in usual of the auxiliary relay 1ZJ being cascaded, normally closed type contact and the magnetic starter C control coil of magnetic latching relay RJ, and all the other two are connected magnetic starter C control circuit and cooling motor main circuit, described disconnected phase monitoring circuit comprises separate unit motor phase failure monitoring circuit, every separate unit motor phase failure monitoring circuit comprises rectifier diode ZD, the light-emitting diode GD and many voltage stabilizing didoe WD, current-limiting resistance XLD and the motor phase failure signal relay coil XJ that cooling motor is shared that are connected to separate unit cooling motor asterism, on motor phase failure signal relay coil, be also parallel with fly-wheel diode XD, more than two separate unit motor phase failure monitoring circuit is connected in parallel.

2. according to open phase protection claimed in claim 1, it is characterized in that: control loop is connected between the fuse RD and magnetic latching relay RJ of cooling motor main circuit.

3. according to open phase protection claimed in claim 1, it is characterized in that: disconnected phase monitoring circuit is connected between the magnetic latching relay RJ and fuse 1RD of cooling motor main circuit.