Ground fault circuit interrupter with combined tripping curve for electric vehicle charging

Abstract

A ground fault circuit interrupter with a residual current device is suggested which comprises a tripping characteristic having a combined time-current curve that implements a minimum tripping time value of a first time-current curve and a second time-current curve for each current value.

Claims

1. Ground fault circuit interrupter (GFCI) with a residual current device comprising a tripping characteristic having a combined time-current curve that implements for each current value a minimum tripping time value of a first time-current curve and a second time-5 current curve.

2. The ground fault circuit interrupter according to claim 1, wherein the first time-current curve is a time-current curve according to the standard UL 2231-2 and the second time-current curve is a time-current curve according to the standard IEC 62752-1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the tripping curve according to the UL 2231-2 standard.

(2) FIG. 2 shows the tripping curve according to the IEC 62752-1 standard.

(3) FIG. 3 shows the resulting tripping curve according to the invention.

DETAILED DESCRIPTION

(4) As can be seen from FIGS. 1 and 2 the tripping characteristics defined by the UL 2231-2 standardtripping curve 1and the IEC 62752-1 standardtripping curve 2do not match. In general, the trip time Ton (vertical axis) decreases with an increasing residual current I (horizontal axis) but there are sections where the trip time Ton associated with the UL 2231-2 standard are above the corresponding time values Ton of the IEC 62752-1 standard and vice versa.

(5) The resulting tripping curve 3 illustrated in FIG. 3 implements the minimum time value of both tripping curves 1, 2 for a given residual current I according to the invention. The tripping characteristic represented by the resulting tripping curve 3 is therefore compliant to UL 2231-2 standard as well as to IEC 62752-1 standard, which standards are incorporated herein by reference.

(6) Moreover there is no additional delay time defined by the resulting tripping curve, meaning that the implemented combined curve utilizes the maximum permissible tripping time (according to the respective standard) in order to avoid false tripping.