接地指导EMC EMC L1 L1 L2 N L2 N L3 PE L3 PE I I PE TN-S TT PE 1-1 1-2 TN-S TT 1-3 V V KV I V I 0V V 1-3 1-4 V EMC EMC 1 EMI . 2 1-10 100 1-5 1-6 1-7 1-5 1-6 1-7 1M I 1-8 1-9 I 1-8 1-9 3 1-10 1-11 Vn 1 2 3 4 5 1-10 1-11 mV 10KHz 300Hz 1MHz 30KHz 1 2 1-12 EMC 1-13 TN-S PE EMC EMC L N PE -48V 1 -48V RETURN EMC 2 3 EMC 1-13 PE PGND FG -----------BGND DC-RETURN--GND ------------------------DGND-------------------------AGND-------------------------LGND--------------------------48V(+24V) PE 1 2 K.27 3 4 1996 1994 Bonding configurations and earthing inside a telecommnication building ITUT YDJ 26-89 EMC EMC 1 EMC 1 EMC 2 3 1 3-1 -48V +24V -48V -48V -48V PE EMI -48V -48V -48V 1 2 3-1 -48V EMI -48V -48V -……