Internal protection circuit for electrically driven device

Claim 2

A protection circuit for providing additional internal protection to a device contained within a shell of said device, said device being driven by an electric motor having an internal line break to interrupt electric motor power to said motor responsive to a specific operating condition of said motor, said circuit comprising: a sensor for detecting a predetermined condition of said device; power means disposed within said shell for providing power to said circuit including an auxiliary winding within said motor and electromagnetically coupled thereto for supplying power relatively lower than said power to said motor; means for assisting in actuating said line break including a heater thermally coupled to said break for thermal actuation thereof to interrupt power to said motor; and power connection means for connecting said power means to the heater in response to said sensor detecting a certain predetermined condition.

Claim 3

The protection circuit of claim 1 including a plurality of sensors for detecting various predetermined conditions of said device with each of said sensors causing said actuation means to interrupt power to said motor in response to the detection of a certain predetermined condition.

Claim 4

The protection circuit of said claim 1 wherein said sensor is a pressure sensor.

Claim 5

The protection circuit of claim 3 wherein said device is a fluid machine having a gas discharge path and said sensor is located to sense pressure in said gas discharge path.

Claim 6

The protection circuit of claim 4 wherein said sensor is adapted to detect a low pressure condition indicative of reverse rotation of said fluid machine.

Claim 7

The protection circuit of claim 1 wherein said sensor is a temperature sensor.

Claim 8

The protection circuit of claim 6 wherein said device includes a discharge path and said sensor is located so as to detect temperature in said discharge path.

Claim 9

The protection circuit of claim 1 wherein said power connection means includes at least one switch with normally open contacts which are closed in response to the detection of a certain predetermined operating condition.

Claim 10

The protection circuit of claim 8 including a plurality of switches disposed in parallel relationship such that any one of said plurality of switches can function to connect said power to said heater to actuate said line break.

Claim 11

In a shell enclosed device having an internal electric drive motor including motor windings, and an internal line break thermally responsive to said motor for interrupting power to said motor upon the occurrence of a specific temperature of current level in said motor, an internal protection circuit comprising: condition sensing means within said shell for sensing a predetermined condition within said shell; heater means thermally coupled to said internal line break; an auxiliary winding within said motor electromagnetically coupled to said motor windings for supplying relatively low power to said heater means when connected thereto; and actuating means responsive to said condition sensing means to connect said auxiliary winding to said heater means to assist in actuating said line break and interrupting power to said motor when a certain predetermined condition is sensed.

Claim 12

In a shell enclosed device having an internal electric drive motor including motor windings, and an internal line break thermally responsive to said motor for interrupting power to said motor upon the occurrence of a specific temperature of current level in said motor, an internal protection circuit comprising: condition sensing means within said shell for sensing a predetermined condition within said shell; heater means thermally coupled to said internal line break; an auxiliary winding within said motor electromagnetically coupled to said motor windings for supplying relatively low power to said heater means when connected thereto; and actuating means responsive to said condition sensing means to connect said auxiliary winding to said heater means to assist in actuating said line break and interrupting power to said motor when a certain predetermined condition is sensed.

Claim 13

The internal protection circuit of claim 10 wherein said condition sensing means comprises a plurality of sensors located in said device to detect various predetermined operating conditions of said device, with each of said sensors causing said actuating means to interrupt power to said motor in response to the detection of a certain predetermined conditions.

Claim 14

The internal protection circuit of claim 10 wherein said condition sensing means comprises a pressure sensor.

Claim 15

The internal protection circuit of claim 12 wherein said device is a fluid machine with a gas discharge path and said sensor is located in sense the pressure conditions in said discharge path.

Claim 16

The internal protection circuit of claim 13 wherein said sensor is adapted to detect a certain low pressure condition which is indicative of reverse rotation of said fluid machine.

Claim 17

The internal protection circuit of claim 10 wherein said condition sensing means is a temperature sensor.

Claim 18

The internal protection circuit of claim 14 wherein said fluid machine includes a gas discharge path and said sensor is located to sense the temperature conditions is said gas discharge path.

Claim 19

The internal protection circuit of claim 10 wherein said actuating means includes at least one normally open switch which closes in response to the detection of a certain predetermined operating condition to thereby connect said auxiliary winding to said heater means.

Claim 20

The internal protection circuit of claim 17 including a plurality of switches disposed in relative parallel relationship such that the closing of any one switch in response to the detection of a certain predetermined condition will cause the said power means to be applied to said heater means and thereby actuate said line break to interrupt power to said motor.

Claim 21

In a hermetic scroll compressor having a shell, an inlet, fixed and orbiting scroll means, a gas discharge path, motor means within said shell including motor windings and an internal line break including normally closed contacts thermally responsive to the temperature and current of said motor means for opening and interrupting power to said motor means upon the occurrence of an excessive temperature or current in said motor means, additional internal protection comprising: a circuit including an auxiliary winding within said motor means electromagnetically coupled thereto for supplying relatively low power to said circuit; temperature sensing means within said shell and located in said fixed scroll means including normally open thermostatically responsive contacts responsive to a predetermined temperature at said discharge; first resistance heater means in said circuit in series with said normally open contacts and thermally coupled to said normally closed thermally responsive contacts of said internal line break, whereby when said normally open thermostatically responsive contacts close responsive to a sensed predetermined temperature, said circuit provides power to said first resistance heater means causing said contacts of said internal line break to open and interrupt power to said motor means; pressure sensing means within said shell and located in said fixed scroll means including normally open pressure responsive contacts located so as to be responsive to a predetermined low pressure in said gas discharge path, indicative of reverse rotation of said orbiting scroll means; second resistance heater means in said circuit in series with said normally open contacts of said pressure sensing means and thermally coupled to said normally closed thermally responsive contacts of said internal line break whereby when said normally open pressure responsive contacts close responsive to a sensed predetermined low pressure, said circuit provides power to said second resistance heater means causing said contacts of said internal line break to open and interrupt power to said motor.

Claim 22

In a hermetic scroll compressor having a shell, an inlet, fixed and orbiting scroll means, a gas discharge path, motor means within said shell including motor windings and an internal line break including normally closed contacts thermally responsive to the temperature and current of said motor means for opening and interrupting power to said motor means upon the occurrence of an excessive temperature or current in said motor means, additional internal protection comprising: a circuit including an auxiliary winding within said motor means electromagnetically coupled thereto for supplying relatively low power to said circuit; temperature sensing means within said shell and located in said fixed scroll means including normally open thermostatically responsive contacts responsive to a predetermined temperature at said discharge; first resistance heater means in said circuit in series with said normally open contacts and thermally coupled to said normally closed thermally responsive contacts of said internal line break, whereby when said normally open thermostatically responsive contacts close responsive to a sensed predetermined temperature, said circuit provides power to said first resistance heater means causing said contacts of said internal line break to open and interrupt power to said motor means; pressure sensing means within said shell and located in said fixed scroll means including normally open pressure responsive contacts located so as to be responsive to a predetermined low pressure in said gas discharge path, indicative of reverse rotation of said orbiting scroll means; second resistance heater means in said circuit in series with said normally open contacts of said pressure sensing means and thermally coupled to said normally closed thermally responsive contacts of said internal line break whereby when said normally open pressure responsive contacts close responsive to a sensed predetermined low pressure, said circuit provides power to said second resistance heater means causing said contacts of said internal line break to open and interrupt power to said motor.

Claim 23

A control system comprising an electrical apparatus, electrical supply means to energize the electrical apparatus, electrical supply means to energize the electrical apparatus having first and second power lines, a line break comprising normally closed switching contacts serially connected to one of said power lines, thermally responsive means operably connected to the switching contacts adapted upon selected conditions of the electrical apparatus to open the switching contacts and de-energize the electrical apparatus, auxiliary heater means disposed in heat transfer relationship with the thermally responsive means, electrical energization means for energizing the auxiliary heater means including an auxiliary winding within the electrical apparatus to provide a low voltage power source and means to selectively energize the auxiliary heater to assist in control the state of energization of the electrical apparatus independently of the said selected conditions of the electrical apparatus.

Claim 24

A control system comprising an electrical apparatus, electrical supply means to energize the electrical apparatus, electrical supply means to energize the electrical apparatus having first and second power lines, a line break comprising normally closed switching contacts serially connected to one of said power lines, thermally responsive means operably connected to the switching contacts adapted upon selected conditions of the electrical apparatus to open the switching contacts and de-energize the electrical apparatus, auxiliary heater means disposed in heat transfer relationship with the thermally responsive means, electrical energization means for energizing the auxiliary heater means including an auxiliary winding within the electrical apparatus to provide a low voltage power source and means to selectively energize the auxiliary heater to assist in control the state of energization of the electrical apparatus independently of the said selected conditions of the electrical apparatus.

Claim 25

The control system of claim 20 wherein the line break comprises a thermally conductive housing and auxiliary heater means comprises a flexible sheet of electrically insulative material, an electrically resistive grid disposed on the sheet, the sheet wrapped around at least a portion of the housing.

Claim 26

The control system of claim 21 wherein the sheet of electrically insulative material is adhesively affixed to the housing.

Claim 27

The control system of claim 21 wherein electrical leads are attached to spaced portions of the resistive grid and a heat shrinkable sleeve of electrically insulative material is disposed over the sheet covering the resistive grid and the electrical leads in the vicinity of the spaced portions to provide electrical over surface clearance and strain relief for the electrical leads.

Claim 28

The control system of claim 21 wherein the means of selectively energize the auxiliary heater includes a manually operable on/off switch.

Claim 29

The protection circuit of claim 21 wherein the line break comprises a thermally conductive housing and the actuation means includes a flexible sheet of electrically insulative material, an electrically resistive grid disposed on the sheet, the sheet wrapped around at least a portion of the housing.

Claim 30

The protection circuit of claim 25 wherein the sheet of electrically insulative material is adhesively affixed to the housing.

Claim 31

The protection circuit of claim 25 wherein electrical leads are attached to spaced portions of the resistive grid and a heat shrinkable sleeve of electrically insulative material is disposed over the sheet covering the resistive grid and the electrical leads in the vicinity of said space portion to provide electrical over surface clearance and strain relief for the electrical leads.

Claim 32

The internal protection circuit of claim 10 wherein the line break comprises a thermally conductive housing and the heater means comprises a flexible sheet of electrically insulative material, an electrically resistive grid disposed on the sheet, the sheet wrapped around at least a portion of the housing.

Claim 33

The internal protection circuit of claim 28 wherein the sheet of electrically insulative material is adhesively affixed to the housing.

Claim 34

The internal protection circuit of claim 28 wherein electrical leads are attached to spaced portions of the resistive grid and a heat shrinkable sleeve of electrically insulative material is disposed over the sheet covering the resistive grid and the electrical leads in the vicinity of said spaced portions to provide electrical over surface clearance and strain relief for the electrical leads.

Claim 35

The protection circuit of claim 25 wherein the actuation means includes a manually operable on/off switch.

Claim 36

The additional internal protection of claim 19 wherein the first and second resistance heater means comprise first and second portions respectively of an electrically resistive grid disposed on a flexible sheet of electrically insulative material, the sheet wrapped around at least a portion of the line break.