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b) Earthed DC MAINS SUPPLIES" r! |* o0 X% E5 S+ ?6 p& k" \
If a DC MAINS SUPPLY is connected to protective earth and is entirely within a single building, B9 w6 \* e( U; Q2 w
the MAINS TRANSIENT VOLTAGE shall be assumed to be 71 V peak. If this connection is within" A6 k+ y) |2 d7 ]. e& I- z# u
the EUT, it shall be in accordance with 2.6.1 d).
- O8 ?0 G, }5 H: n' C' l z2 N* GNOTE 3 The connection to protective earth can be at the source of the DC MAINS SUPPLY or at the equipment
) r0 H; n/ { M; Rlocation, or both (see ITU-T Recommendation K.27).* V, S. J% q4 T& j5 k- S3 a3 {
c) Unearthed DC MAINS SUPPLIES
u# B( ~! O$ A2 J2 x- ~5 xIf a DC MAINS SUPPLY is not earthed and located as in b) above, the MAINS TRANSIENT VOLTAGE2 v) c( m! r" d* u6 F
shall be assumed to be equal to the MAINS TRANSIENT VOLTAGE in the AC MAINS SUPPLY from
2 d0 h8 s* T5 E8 e* U. Cwhich the DC MAINS SUPPLY is derived.8 q5 K5 Y: `" q, a/ T% R; T
8 N( m& Y2 V4 N4 _你可以先归类,看属于B,还是C |
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