JPS5847267Y2 - Refrigeration equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an overload protection device for an electric compressor incorporated in a refrigeration system.

Conventionally, in order to protect the electric compressor in a refrigeration system from overload, a bimetal and a resistor are connected in series to the electric compressor. When the temperature rises, the bimetallic contacts open and cut off the current.

However, this merely cuts off the electric current to the electric compressor in the event of an overload, and does not actively eliminate the cause of abnormal current or abnormal temperature rise.

Therefore, even though the cause of overload remains in the cooling system, if the overload protection device is restored, excessive current may flow again or abnormal temperature rise of the electric compressor will occur again, resulting in another overload. There was a drawback that the protection device was activated and restarting was not performed smoothly.

The present invention aims to improve these drawbacks, and will be described below with reference to the drawings showing one embodiment thereof.

1 is an electric compressor, 2 is a condenser, 3 is a pressure reducer such as a capillary tube, and 4 is an evaporator, which are connected in a ring to form a well-known refrigeration cycle refrigerant circuit.

5 is a bypass path connected between the high pressure side 6 (refrigerant discharge port side of the electric compressor 1) and the low pressure side 7 (refrigerant suction side of the electric compressor 1) of the refrigerant circuit of the refrigeration cycle; A solenoid valve 8 is provided.

Reference numeral 9 denotes a conventional overload protection device formed by connecting a bimetal contact 9a and a resistor 9b in series, and connects the electric compressor 1 to a power source E via this overload protection device 9 and a starting relay 10.

An electromagnetic coil 8a for opening the electromagnetic valve 8 is connected in parallel to an overload protection device 9.

Here, when an overload is applied to the electric compressor 1' and the overload protection device 9 is activated, the bimetal contact 9a opens and cuts off the drive current to the electric compressor 1.

Then, the electromagnetic coil 8a is energized and the electromagnetic valve 8 is opened.

As a result, the refrigerant quickly flows from the high pressure side to the low pressure side of the refrigeration cycle refrigerant circuit through the bypass path 5, and the high pressure side pressure and the low pressure side pressure are balanced.

As a result, the overload protection device 9 is restored and no excessive load is applied to the electric compressor, allowing smooth startup.

As is clear from the above embodiments, the present invention provides a bypass path equipped with a solenoid valve between the high pressure side and the low pressure side of the refrigeration cycle refrigerant circuit, and the solenoid coil of this solenoid valve is connected to the overload of the electric compressor. This is connected in parallel to the protection device, and when the overload protection device is activated, it actively removes the overload device, so when the overload protection device returns and the electric compressor restarts, it will smoothly restart. It is something that starts.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration system showing an embodiment of the present invention, and FIG. 2 is an electrical wiring diagram of an electric compressor of the refrigeration system. 1... Electric compressor, 2... Condenser, 3
... pressure reducer, 4 ... evaporator, 5 ...
...Bypass path, 6...High pressure side, 7...
...Low pressure side, 8...Solenoid valve, 8a...
Electromagnetic coil, 9... Overload protection device, E...
···power supply.

Claims (1)

[Scope of utility model registration request] An electric compressor connected to a power source via an overload protection device, a condenser, a pressure reducer, an evaporator, etc. are connected in a ring to form a refrigeration cycle refrigerant circuit. A refrigeration system comprising a bypass path provided between the low pressure side, a solenoid valve provided in the bypass path, and an electromagnetic coil for operating the solenoid valve connected in parallel to the overload protection device.