GB972413A - Apparatus for preventing single-phase operation of three-phase electric motors - Google Patents
Apparatus for preventing single-phase operation of three-phase electric motorsInfo
- Publication number
- GB972413A GB972413A GB1649/63A GB164963A GB972413A GB 972413 A GB972413 A GB 972413A GB 1649/63 A GB1649/63 A GB 1649/63A GB 164963 A GB164963 A GB 164963A GB 972413 A GB972413 A GB 972413A
- Authority
- GB
- United Kingdom
- Prior art keywords
- phase
- current
- ripple
- motor
- contactor
- 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
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/12—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to underload or no-load
- H02H3/13—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to underload or no-load for multiphase applications, e.g. phase interruption
Landscapes
- Protection Of Generators And Motors (AREA)
Abstract
972,413. Protective arrangements. HITACHI Ltd. Jan. 14, 1963 [Jan. 16, 1962], No. 1649/63. Heading H2K. A system for preventing single phase operation of a three phase electric motor 1 comprises current transformers 8, 9 associated with any two of the phase conductors 2, 3, 4 and connected to supply three phase current to a full wave rectifier 10, the output of which passes through the primary of a non-saturable current transformer 11 and a thermal relay 12 supplied with ripple current from the secondary of the transformer 11. Under normal conditions the ripple current is small but in the event of one phase of the supply failing only single phase current will be supplied to rectifier 10 and the amplitude of the ripple will increase sufficiently to operate the thermal relay 12 to close its contacts and thus trip a circuit-breaker 5 to stop the motor. In a modified circuit (Fig. 2, not shown), the contacts of relay 12 are normally closed to energize a contactor. Upon phase failure the contactor is released to stop the motor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP85562 | 1962-01-16 | ||
| FR921582A FR1344697A (en) | 1962-01-16 | 1963-01-16 | Apparatus for preventing single-phase operation of a three-phase motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB972413A true GB972413A (en) | 1964-10-14 |
Family
ID=73198045
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1649/63A Expired GB972413A (en) | 1962-01-16 | 1963-01-14 | Apparatus for preventing single-phase operation of three-phase electric motors |
Country Status (2)
| Country | Link |
|---|---|
| FR (1) | FR1344697A (en) |
| GB (1) | GB972413A (en) |
-
1963
- 1963-01-14 GB GB1649/63A patent/GB972413A/en not_active Expired
- 1963-01-16 FR FR921582A patent/FR1344697A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR1344697A (en) | 1963-11-29 |
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