JPS5495348A - Apparatus for protecting ac three-phase load against phase omission - Google Patents

Apparatus for protecting ac three-phase load against phase omission

Info

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
Application number
JP309478A
Other languages
Japanese (ja)
Inventor
Tsuyoshi Hokutou
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shimadzu Corp
Original Assignee
Shimadzu Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shimadzu Corp filed Critical Shimadzu Corp
Priority to JP309478A priority Critical patent/JPS5495348A/en
Publication of JPS5495348A publication Critical patent/JPS5495348A/en
Pending legal-status Critical Current

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  • 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
JP309478A 1978-01-13 1978-01-13 Apparatus for protecting ac three-phase load against phase omission Pending JPS5495348A (en)

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)

* Cited by examiner, † Cited by third party
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

Cited By (4)

* Cited by examiner, † Cited by third party
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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