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| DSH 791
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| TRFs – Values to be reported# S5 D; L1 n/ V$ Y
| General
; [8 v: k( p' t0 h | All IEC standards
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Standard(s):: k# b3 m) R P. l
All IEC standards
& s. S" w$ ?- @6 {Subclause(s):
4 K) l, S& H0 g+ |. kGeneral& s% F0 A; |& v
No. Year
1 p; e7 a% B QDSH
9 x/ U5 e" i5 {7 Q$ t' @0791 20105 r4 _$ Y& `4 U, E' q A
Category: VARIOUS Developed by: WG4) o. [/ O. D3 l- F8 d) ?8 [
Subject:9 t9 G" O8 ?$ ]2 E
TRFs – Values to be reported7 L9 \$ ?* T0 D- C$ H
Key words:. Y$ y( _9 N* M" L3 t
- TRFs
8 |" w; L* j+ x( |0 [$ Y: ?- Required minimum value
. t! P% h& B' u+ c% ?- OD-CB2020 Ed. 1.7 § 4.6.1
9 |! q$ M* R/ {: H0 MApproved at the 48th CTL
9 o( P: K6 I# M! F+ u# RPlenary Meeting, in 2011, X) R9 ?) j# `# b# h: _, u
Question:# g1 Z3 ] T! }
Based on OD-CB2020-Ed.1.7 Sub-clause 4.6.1., it is not allowed to use statements such as “OK”, “meets! f4 ]: l& e; H( n2 j
the standard”, “more than”, “less than”, or similar instead of the measured value, unless otherwise, N/ n5 b9 {- A* |+ q, S( R9 t
specified by CTL.
" Y$ `8 q. W0 M/ y2 _1 ]; jIn certain cases the required minimum value is exceeded by a great margin.4 o" y( R8 |7 ?7 S4 ?4 g
Decision:) r7 s( [7 U8 @$ F: |
In case that the measured minimum or maximum value is exceeding or is below the limit value for2 g$ h+ K7 O, f
more than 30%, the value given in the TRF should be >[minimum required value + 30%] or should
% F3 x/ Q' i' Q6 C, Y/ ]) M- wbe < [maximum required value - 30%]. The accuracy of the used instruments is in line with CTL- Q# b/ m$ J& t5 x4 U, m G
DSH 251B or better.
# e# G0 y" o1 {5 dFor example measurement of insulation resistance:+ Q% R! D0 @4 K' E2 q$ b
· required 5 M;
2 F9 }. {+ {& f: @, }9 E2 d& O· measurement range of test equipment 0 … 10 M;6 v `6 e3 m1 q# W8 M
· the measurement instrument shows full-scale deflexion.
7 X4 S/ ?/ z9 s2 ?; V8 b1 f2 CThe value given in the TRF should be > 6.5 M.
7 k' }5 }0 L! U& F5 j _4 X7 yFor example measurement of creepage distance:
0 i1 U! {. S: z- J$ C- The required creepage distance is 3.0 mm.;0 ]) @' i' ~2 G$ t
- The real distance is exceeding 4 mm.;
$ Y0 F. B+ K4 R* H+ @) t9 C5 fThe value given in the TRF should be > 4 mm.+ _8 }9 B$ P4 B! U5 b* u9 L: e: Y n
For example measurement of leakage current:- y+ [& P& Y: `8 Q
- The current limit is 0.5 mA;
/ @2 J, o# d. s. H; K- The real current is below 0.35 mA;5 k5 Y+ v- ~4 B+ O
The value given in the TRF should be < 0.35 mA.
+ T5 h* t$ m5 J& b4 C! i# bThe following two situations are allowed:4 M4 h, V r( y, l e3 Q
1 – The meter reading is less than the smallest measurable graduation on a meter scale. For6 Y' a& ~# |% e0 ]* M U
example, touch current measured was less that 0.1 mA.0 k+ Z# y( E. ]
2 – In checking creepage and clearance distances with a probe the same dimension as the8 ^) V: N& {" i7 ?0 v, V
requirements. For example, creepage and clearance distances were greater than 0.8 mm./ F8 M+ Z5 {3 {; A3 Y
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