GB771874A - Improvements relating to thermal protection of single phase a.c. motors - Google Patents
Improvements relating to thermal protection of single phase a.c. motorsInfo
- Publication number
- GB771874A GB771874A GB26606/55A GB2660655A GB771874A GB 771874 A GB771874 A GB 771874A GB 26606/55 A GB26606/55 A GB 26606/55A GB 2660655 A GB2660655 A GB 2660655A GB 771874 A GB771874 A GB 771874A
- Authority
- GB
- United Kingdom
- Prior art keywords
- motor
- winding
- current
- contacts
- starting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/08—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors
- H02H7/085—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against excessive load
Landscapes
- Motor And Converter Starters (AREA)
Abstract
771,874. Control of A.C. motors. GENERAL ELECTRIC CO. Sept. 16, 1955 [Sept- 16. 1954], No. 26606/55. Class 38(3) A split-phase motor having running winding 2 and starting winding 3 is pro- 'tected against over-heating when stalled by means of an auxiliary circuit, comprising resistor 14 and coils 17, 18, which is connected in parallel with that portion of the running winding circuit which includes bimetal member 8, heater 9, and relay coil 10, the coils 17, 18, being in transformer relation with the starting and running windings respectively. When the motor is operating normally, a high current passes through the auxiliary circuit so that the current passing through the elements 8, 9, is insufficient to open the spring- biased overload contacts 7. When the motor is stalled, however, or fails to start, no speed-responsive voltage is induced in the winding 17, the current in the auxiliary circuit is reduced, and that passing through the other branch circuit increases until the contacts 7 are actuated to disconnect the motor. A heavy surge of current when the motor is started causes coil 10 to close contacts 11 and energize the starting winding which is disconnected when the motor reaches a predetermined speed.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US771874XA | 1954-09-16 | 1954-09-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB771874A true GB771874A (en) | 1957-04-03 |
Family
ID=22136581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB26606/55A Expired GB771874A (en) | 1954-09-16 | 1955-09-16 | Improvements relating to thermal protection of single phase a.c. motors |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB771874A (en) |
-
1955
- 1955-09-16 GB GB26606/55A patent/GB771874A/en not_active Expired
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