JPS5495348A - Apparatus for protecting ac three-phase load against phase omission - Google Patents
Apparatus for protecting ac three-phase load against phase omissionInfo
- Publication number
- JPS5495348A JPS5495348A JP309478A JP309478A JPS5495348A JP S5495348 A JPS5495348 A JP S5495348A JP 309478 A JP309478 A JP 309478A JP 309478 A JP309478 A JP 309478A JP S5495348 A JPS5495348 A JP S5495348A
- Authority
- JP
- Japan
- Prior art keywords
- relay
- phase
- resistors
- capacitors
- omission
- 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.)
- Pending
Links
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
PURPOSE: To permit reliable phase detection without using any expensive current transformer by providing rectifying elements in series with resistors and capacitors between adjacent ones of the three phase bus bars and bridging the output terminals of the rectifying elements with a DC relay.
CONSTITUTION: A parallel circuit consisting of capacitors C1 to C4 and resistors R1 to R4 is connected to points R', S' and T' of the respective three phases through diodes D1 to D5. A DC relay RY is connected to the output terminals of the diodes D2, D3 and D5, and a brake contact b of the relay RY is controlled by an on-off control circuit 4 to open contacts 3 of a load circuit main switch 2. Thus, when the three phases are normal, the difference voltage impressed between the opposite terminals of the DC relay RY is low. In case of phase omission, a high difference voltage is applied due to the discharge characteristics of the capacitors and resistors to cause momentary operation of the relay RY. In this way, burning of the motor can be prevented.
COPYRIGHT: (C)1979,JPO&Japio
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP309478A JPS5495348A (en) | 1978-01-13 | 1978-01-13 | Apparatus for protecting ac three-phase load against phase omission |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP309478A JPS5495348A (en) | 1978-01-13 | 1978-01-13 | Apparatus for protecting ac three-phase load against phase omission |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5495348A true JPS5495348A (en) | 1979-07-27 |
Family
ID=11547749
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP309478A Pending JPS5495348A (en) | 1978-01-13 | 1978-01-13 | Apparatus for protecting ac three-phase load against phase omission |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5495348A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6358764U (en) * | 1986-10-03 | 1988-04-19 | ||
US8107204B2 (en) | 2007-11-13 | 2012-01-31 | Emerson Climate Technologies, Inc. | Three-phase detection module |
-
1978
- 1978-01-13 JP JP309478A patent/JPS5495348A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6358764U (en) * | 1986-10-03 | 1988-04-19 | ||
US8107204B2 (en) | 2007-11-13 | 2012-01-31 | Emerson Climate Technologies, Inc. | Three-phase detection module |
US8724275B2 (en) | 2007-11-13 | 2014-05-13 | Emerson Climate Technologies, Inc. | Three-phase detection module |
US9557389B2 (en) | 2007-11-13 | 2017-01-31 | Emerson Climate Technologies, Inc. | Three-phase detection module |
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