DocumentCode
951044
Title
Differential transformer cores for ground fault interrupting circuit breakers
Author
Finke, Güenter B.
Author_Institution
Magnetic Metals Company, Camden, N.J.
Volume
10
Issue
2
fYear
1974
fDate
6/1/1974 12:00:00 AM
Firstpage
144
Lastpage
148
Abstract
The magnetic requirements of differential transformers used in ground fault interrupters (GFI) for the sensing of 5 mA ground faults over the temperature range from -35°C to +66°C have been established. Ring laminations made of vacuum-melted permalloy and annealed so that the magnetocrystalline anisotropy 
just above the maximum operating temperature meet these requirements. Such heat treatment will produce rings with low remanence in which the low-flux-density permeability is stable with temperature and changes little from the demagnetized to the remanent state. The processing of rings and the influence of impurities are briefly discussed.
just above the maximum operating temperature meet these requirements. Such heat treatment will produce rings with low remanence in which the low-flux-density permeability is stable with temperature and changes little from the demagnetized to the remanent state. The processing of rings and the influence of impurities are briefly discussed.Keywords
Differential transformers; Ground-fault-interrupting circuit breakers; Magnetic cores; Circuit breakers; Circuit faults; Interrupters; Lamination; Land surface temperature; Magnetic anisotropy; Perpendicular magnetic anisotropy; Temperature distribution; Temperature sensors; Transformer cores;
fLanguage
English
Journal_Title
Magnetics, IEEE Transactions on
Publisher
ieee
ISSN
0018-9464
Type
jour
DOI
10.1109/TMAG.1974.1058304
Filename
1058304
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