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b) Earthed DC MAINS SUPPLIES& P! d/ S D8 K' t
If a DC MAINS SUPPLY is connected to protective earth and is entirely within a single building,
+ A3 {2 v- N. uthe MAINS TRANSIENT VOLTAGE shall be assumed to be 71 V peak. If this connection is within3 P* f# V3 O2 \" l7 |
the EUT, it shall be in accordance with 2.6.1 d).
. O& e: F$ j) w; I$ F `NOTE 3 The connection to protective earth can be at the source of the DC MAINS SUPPLY or at the equipment0 W" m6 g9 k! J l: v* l/ S/ u
location, or both (see ITU-T Recommendation K.27).; a, I, Q' k% T+ c
c) Unearthed DC MAINS SUPPLIES
3 v$ ^% ^! l1 @) z8 Y; K A3 qIf a DC MAINS SUPPLY is not earthed and located as in b) above, the MAINS TRANSIENT VOLTAGE
% r; q+ b# ]' K7 `shall be assumed to be equal to the MAINS TRANSIENT VOLTAGE in the AC MAINS SUPPLY from
" I) N$ D3 `( L; Q7 Q4 B; G; owhich the DC MAINS SUPPLY is derived.
! `. T: g$ ^8 n2 m8 o5 y0 @- Y; d/ l
你可以先归类,看属于B,还是C |
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