Protective Impedance versus no-load voltage6 @4 m5 U, a3 _
18f)( t8 r9 @2 n, @; s
60601-1(ed.2);am1;am2# v' A( S( V4 w+ M
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Standard(s)- (year and edition): 3 @. f- y* B: B- P1 O t8 |IEC 60601-1:1988 Ed.2 Am1+Am27 K9 Q7 I& e! c
Sub clause(s): 18f) $ t t2 r- H( ?8 F- R, ISheet n°: DSH-432 " N% L! T" i- D# I7 eSubject: Protective Impedance versus noload voltage % i0 \! k, u. [; ~* XKey words: Protective, impedance, earth, connection, no-load ' @& H& H& J2 I; t+ ^; m5 jConfirmed by CTL at its 39th meeting, in Cologne2 s) `* r: d4 O! U' x
Question:" \) f* W8 K% R& f# D* q
EQUIPMENT for example having a rated current of 30 A require a test current of 1.5 times 30 A.0 j4 }4 H8 G0 {4 M" m. d1 e' S, Z2 G
With a maximum impedance of 0.2 W the voltage drop has to be 9 V (0.2 W * 45 A = 9 V). This is" ~) g: G* h6 z5 @; {
in contradiction to the required no-load voltage of 6 V maximum.2 O% o& ]: B3 r
Decision:- y, t: N8 x8 T7 z5 x. P
Measuring the protective earth connection has in fact two reasons. It is to determine impedance 8 n: X" T- ~; f; Zand cross-sectional area of protective earth connections. For a measuring current of 25 A both0 \/ R9 K7 ^: o' H: E
can be done with one measurement. Requiring a measuring current of more than 25 A it shall be , G0 A, p) X0 w0 o5 j2 c0 Rsplitted up into two measurements. In this case, the impedance shall be determined first, using a # ]* F4 b. t2 Z4 I$ e [2 cvoltage not exceeding 6 V. 3 x+ ]2 _: T( S9 yIf cross-sectional area of the protective earth connections cannot be determined as equal to the ( ^5 t1 h5 U5 Y yone for the phase by measurement of the area, then measurement with current shall be from a $ t2 Q+ t. s% K3 Z5 z6 }source with a higher voltage than 6 V. . ? k7 l7 ?) z( `; S. X9 w - h4 S, y- ~) s3 W[attach]77075[/attach] " n+ Z3 E% h/ { c2 f
DSH 432