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
Link To Document :
