Title:
CONTROL METHOD FOR CIRCUIT BREAKER
Document Type and Number:
Japanese Patent JP3292856
Kind Code:
B2
Abstract:
PURPOSE: To prevent unnecessary or erroneous function by resampling the load current value after a time limit operation and delivering a trip drive signal only when a current higher than a predetermined level is detected.
CONSTITUTION: A circuit breaker begins the control operation (S101). The load current is then sampled (S102) and a load current value is operated based on the sampled value (S103) A decision is made whether an overcurrent is flowing based on the operated value of load current. When an overcurrent is detected, a time limit is reset (S105). A time limit value corresponding to the overcurrent value is operated (S106) and a decision is made whether a predetermined time limit is reached (S107). Upon reaching the predetermined time limit, the load current is resampled (S108) and a decision is made whether a load current higher than a predetermined level is flowing. A trip drive signal is outputted only when the detection of a load current higher than a predetermined level is determined.
Inventors:
Eetsu Sato
Hideki Hayakawa
Hideki Hayakawa
Application Number:
JP829894A
Publication Date:
June 17, 2002
Filing Date:
January 28, 1994
Export Citation:
Assignee:
株式会社日立製作所
株式会社 日立インダストリイズ
株式会社 日立インダストリイズ
International Classes:
H02H3/093; (IPC1-7): H02H3/093
Domestic Patent References:
| JP522840A | ||||
| JP1270718A | ||||
| JP4372519A | ||||
| JP6141456A |
Attorney, Agent or Firm:
Yoshihiko Izumi