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b) Earthed DC MAINS SUPPLIES+ Q# X) Z3 f4 K
If a DC MAINS SUPPLY is connected to protective earth and is entirely within a single building,
: B& |5 z' [+ fthe MAINS TRANSIENT VOLTAGE shall be assumed to be 71 V peak. If this connection is within, e& L( o f5 i- u0 X& ^
the EUT, it shall be in accordance with 2.6.1 d).) w, |! H& K: C! G) n* |
NOTE 3 The connection to protective earth can be at the source of the DC MAINS SUPPLY or at the equipment' M3 k Y1 Z* a4 V3 e8 _- A1 ~
location, or both (see ITU-T Recommendation K.27).$ ?% I3 w6 _0 z% F
c) Unearthed DC MAINS SUPPLIES, G6 f$ Z, U# {3 ]: \9 h9 d
If a DC MAINS SUPPLY is not earthed and located as in b) above, the MAINS TRANSIENT VOLTAGE$ s* }9 y. M5 b$ C$ o( m
shall be assumed to be equal to the MAINS TRANSIENT VOLTAGE in the AC MAINS SUPPLY from
- Y/ a* Q) |* n, m5 o5 U6 ~which the DC MAINS SUPPLY is derived./ k, c4 I9 p% r1 i* ^
# x) v/ J) B2 d! ?你可以先归类,看属于B,还是C |
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