JPH035673A - Freezing cycle device - Google Patents

Abstract

PURPOSE:To improve an operating efficiency and a reliability by a method wherein a protection device operation sensing circuit for use in detecting a presence or a non-presence of at least one operation of an over-current protection deice as well as a high voltage switch are provided. CONSTITUTION:In case that at least one of a high voltage switch 7 and an over-current protection device 8, e.g. a switch 7 is operated, an electrical energization of an exciting coil 2a of a magnet switch 2 is shielded by releasing its normal-closed contact point, resulting in that a contact point of the switch 2 is released. In turn, at a protection device operation sensor circuit 5, an electrical potential at one end point C of a photo-triac 10 is lower than an electrical potential at the point B and a sinusoidal wave voltage is applied to the point B, so that one of the triacs 10 comes electrically conductive to generate light. This emitted light is received by a photo-transistor 11 and then the transistor 11 comes electrically conductive and thus 5V charged in a capacitor C1 is conducted to an earth through the transistor 11. An electrical potential at an input end point E becomes almost 0V, a control part 13 receives this 0V to assume that the switch 7 is operated and its subsequent operation is controlled.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention is a high voltage switch and overcurrent protection! ! The present invention relates to a refrigeration cycle device having a high-pressure switch and an overcurrent protection device, and more particularly to a refrigeration cycle device including a protection device operation detection circuit that detects whether a high-voltage switch and an overcurrent protection device are operating.

(Prior art) Conventionally, this type of refrigeration cycle device has a high-pressure switch that cuts off current to the compressor when the pressure on the high-pressure side, such as the discharge pressure of the compressor, rises to a predetermined pressure, and a high-pressure switch that cuts off power to the compressor when an overcurrent flows into the compressor. Sometimes, an 11-item filtration current protection device (IOL) is installed to block the current flow to protect the compressor.

These high-voltage switches and overcurrent protection devices are connected downstream of their contacts to an AC interrupt circuit, which is the input port for the A and II controllers, which are made up of a microcomputer and control the operation of the compressor, etc. By opening these contacts when these protection devices are in operation, the power supply to the AC interrupt circuit is cut off, and the operation of the compressor is stopped by stopping the operation of the 11th generator.

Therefore, such conventional refrigeration cycle devices do not have their own circuit for detecting the operation of the protection device.

(Problem to be Solved by the Invention) However, in such a conventional refrigeration cycle device, for example, when a high-voltage switch operates, the power supply to the 111 controller itself consisting of a microcomputer is cut off and its operation is stopped. There is a problem that appropriate control cannot be performed.

In other words, if the refrigeration cycle equipment is air conditioning and the high pressure switch operates during cooling operation, the cooling load in the shell is lighter than the heating load, so if there is a malfunction, Because of this, it is desirable not to automatically restart the cooling operation after it has been stopped.

On the other hand, if the high pressure switch operates during heating operation of Air Conditioning I, it is often an overload because the heating load is higher than the cooling load, and it will automatically return after the heating operation is stopped. You may let them.

However, as described above, in the conventional example, when the high-pressure switch is operated, the υV11II unit itself stops operating due to energization, so it is not possible to perform iil+ control such as automatically returning the heating operation again after the high-pressure switch is operated.

Therefore, the present invention was made in consideration of the above circumstances, and is an IC.
Its purpose is to maintain; by detecting the operation of 1iff,
It is an object of the present invention to provide a refrigeration cycle device that can appropriately perform a and l all after the operation of the protection device, and can improve operating efficiency and reliability.

[Structure of the invention]

(Means for solving the problem) The present invention provides the above-mentioned X! In order to solve the II problem, it is constructed as follows.

In other words, the present invention enables the power supply to the compressor to be 0N-OF.
a high-pressure switch that cuts off current to the compressor when the pressure side pressure of the compressor exceeds a predetermined pressure; In a refrigeration cycle device having a current protection device, the normally open contacts of the high voltage switch and the overcurrent protection device are connected in series to the output side of the excitation coil of the magnetic switch, and the high voltage switch and the overcurrent protection device are connected in series. At least one of the high-voltage switch and the overcurrent protection device is activated by detecting the presence or absence of a current flowing through the output side of the excitation coil of the magnetic switch, which trips when at least one of the devices operates and opens its contacts. The protection device operation detection circuit that detects the presence or absence of operation is
It is characterized by having been pressed.

(Function) When at least one of the high-voltage switch and the overcurrent protection device operates, its contacts open, the excitation coil of the magnetic switch is demagnetized, and the magnetic switch is tripped.

Then, the no-current state of the excitation coil is detected by the protection device operation detection circuit, and it is detected that the protection device has operated.

Therefore, according to the present invention, since it is possible to detect whether or not the protection bag U is in operation, it is possible to appropriately perform v control after the protection bag U is operated, thereby improving the operating efficiency and reliability of the refrigeration cycle device. You can also aim to improve your skills.

(Example) An example of the present invention will be described below based on FIGS. 1 and 2.

FIG. 1 is a wiring diagram showing the overall configuration of an embodiment of the present invention. In the figure, a three-phase Ti source 1 includes three phases (R, S, T
), a converter 3a, an inverter 3b, and a compressor 4 are connected in series in this order.

The magnet switch 2 connects a required one phase, for example, the T phase, of the three-phase three wires R, S, and T connecting the three-phase power supply 1 and the magnet switch 2 to the input side of the excitation coil 2a, for example, the T phase of the magnet switch relay. It is connected via a normally closed contact 6, and a protective device operation detection circuit 5 is provided.

The protective device operation detection circuit 5 is connected to the output side of the excitation coil 2a,
High pressure switch 7 and over? 1! The normally open contacts of the current protection device 8 are connected in series in this order, and then connected to, for example, the R phase of the three-phase three-wire system.

Also, the output side of the excitation coil 2a and the normal 1 of the high voltage switch 7 are connected to each other.
A midpoint A of the wiring connecting the two points 1ifIF is connected to one end B of the phototriac 10 of the photocoupler 9 via a resistor R1 having a sufficiently large resistance with respect to the impedance Z of the magnet switch 2.

The other end C of the phototriac 10 is connected to a three-phase, three-wire, for example, R phase.

On the other hand, the output end of the phototransistor 11 of the photocoupler 9 is connected to a 5V battery 12 via a resistor R2, and is also connected to the input end E of the υBit unit 13 via a V1 resistor R3. vJ weapon 13 input terminal E and resistor R3
The middle of the wiring connecting the two is grounded via a capacitor C1.

The control unit 13 has means for applying an operating frequency command signal to the inverter 3b and controlling the rotation speed of the compressor 4 to ii'Jtll.

Further, the tIIJtil device 13 has a control means for closing the normally closed contact 17i1 of the magnet switch relay 6.

Next, the operation of this embodiment will be explained.

First, when a control signal is given to the magnet switch relay 6 from IIJtilW13, its normal m contact is closed, and the excitation filter 2a of the magnet switch 2 is energized through this closed contact, thereby closing the contact of the magnet switch 2.

For this purpose, the voltage of the three-phase power supply 1 is applied to the converter 3a, the inverter 3b, and the compressor 4 through the diagonal contacts of the magnetic switch 2, and the compressor 4 is driven at the required rotational speed to drive the refrigeration cycle device. For example, an air conditioner is operated.

During this air conditioning operation, if both the high voltage switch 7 and the overcurrent protection device 8 are malfunctioning, the current flowing through the excitation coil 2a of the magnetic switch 2 It flows through the contact to the T phase.

At this time, in the protection device operation detection circuit 5, the excitation coil 2
The potentials at point A on the output side of a and one 1fiB point of the phototriac 10 of the photocoupler 9 are at the same potential at llfffi level.

Therefore, the phototriac 10 of this photocoupler 9 is not energized and is OFF, and does not emit light.

Therefore, the phototransistor 11 is also turned off,
5V of the battery 12 is applied to the potential at the output 'IAD point, and this 5V is further charged to the capacitor C1 via the resistor R2 and the resistor R3.

Therefore, the control 11513 has a potential of 5 at its input end point E.
In response to (2), it is determined that both the high voltage switch 7 and the 'A current protection device 8 are inoperable and T is normal.

On the other hand, when at least one of the high voltage switch 7 and the excess I flow protection mHm8, for example, the high voltage switch 7 operates,
By opening the normally open contact, the excitation coil 2a of the magnet switch 2 is de-energized, so the excitation coil 2a
is deenergized, the contacts of the magnet switch 2 are opened, the power supply from the three-phase m source 1 to the converter 3a is cut off, and the power supply to the inverter 3b and the compressor 4 is cut off, thereby stopping their driving. As a result, air conditioning operation also stops.

On the other hand, in the protection device operation detection circuit 5, since the normally open contact of the high voltage switch 7 is opened, the potential at point C at one end of the phototriac 10 becomes lower than the potential at the other eight points. Since a sinusoidal voltage is applied to the phototriac 10 as shown in FIG. 2, one of the phototriacs 10 becomes conductive (ON) and emits light.

This light emission is received by the phototransistor 11, and the phototransistor 11 becomes conductive (ON), so that the voltage of the battery 12 charged in the capacitor C1 is grounded through the phototransistor 11 which is conducting.

Therefore, as shown in FIG. 2, 5.times. is applied to point D of the phototransistor 11, while the potential at point E of the input terminal of the 1tlJ1211 device 13 becomes almost Ov.

1. By receiving the potential O■ at the input terminal E, the IJ III device 13 determines that the high voltage switch 7 has been operated, and performs subsequent air conditioning operation RA control.

That is, if the return of the high pressure switch 7 is not detected within 10 seconds from the operation of the high pressure switch 7 while the air conditioning operation is cooling, the system does not automatically return after the cooling operation is stopped and displays an abnormality.

In other words, since the cooling load is light compared to the heating load, if the high-pressure switch 7 operates during cooling operation, it is more likely to be due to a malfunction than to an overload, so the control that does not automatically restore is necessary. is necessary. Note that the 10 seconds for abnormality determination is provided as the time required for determination to prevent abnormal stoppage due to noise malfunction.

On the other hand, if the high pressure switch 7 operates during heating operation, the heating load is higher than the cooling load, and the original prisoner is often overloaded. If the high-pressure switch 7 returns within seconds, υ control is performed to automatically return the heating operation after a required period of time has passed since the heating operation was stopped. During these 30 seconds, it is common sense that if the compressor 4 stops, the high pressure side pressure will be the high pressure switch 7's operation 1! !
The current situation is sufficient for the price to drop to the point of return.

Therefore, according to this embodiment, the operation of the high-voltage switch 7 and the overcurrent protection bag d8 can be detected, and the control after the operation of these protection devices can be appropriately performed, so that the operating efficiency of the refrigeration cycle device can be improved. It is possible to improve the performance and reliability.

Also, during normal operation when the 2I device does not operate, N current does not flow through resistor R1, so heat generation in resistor R1 is suppressed!
, II.

In addition, although the three-phase compressor 4 was explained in the said Example, this invention is not limited to this, but can also be applied to a single-phase compressor.

(Effects of the Invention) As explained above, the present invention is capable of detecting whether or not the high voltage switch and overcurrent protection device are in operation using the protection device operation detection circuit. t of the subsequent refrigeration cycle equipment, IJ In
can be carried out appropriately, it is possible to improve both the operating efficiency and the reliability of the entire device.

[Brief explanation of the drawing]

FIG. 1 is a wiring diagram of a main part of an embodiment of a refrigeration cycle device according to the present invention, and FIG. 2 is a waveform diagram showing voltage waveforms at points B, D, and E shown in FIG. 1. 2... Magnet switch, 2a... Excitation coil,
5...Protective device operation detection circuit, 7...High voltage switch, 8...Overcurrent protection device, 9...Photocoupler, 1
0...Phototriac, 11...Phototransistor. Figure 1

Claims (1)

[Claims] a magnetic switch that controls ON/OFF power supply to the compressor; a high-pressure switch that cuts off power to the compressor when the high-pressure side pressure of the compressor exceeds a predetermined pressure; In a refrigeration cycle device having an overcurrent protection device that cuts off current to the high voltage switch, the normally closed contacts of the high voltage switch and the overcurrent protection device are connected in series to the output side of the excitation coil of the magnetic switch, and the high voltage The high-voltage switch and overcurrent protection are provided by detecting the presence or absence of a current flowing through the output side of the excitation coil of the magnetic switch, which trips when at least one of the switch and the overcurrent protection device operates and opens its contacts. A refrigeration cycle device comprising a protection device operation detection circuit that detects whether or not at least one of the devices is in operation.