3???ù±?????
??3.1??±??¤????
??3.1.1??TN ????
TN system???????????????±?????????????è±?????????????·??¨??±??¤???????????????????????????ù????????????±??¤????????????TN??????????????????????
a. TN-S????????????????????·???????????????±??¤??????
b. TN-C-S????????????????·???????????±??¤?????????????????ù????????
c. TN-C??????????????????????????????±??¤?????????????????ù????????
×?????????×???T±í?????????????????±??????????????×???N±í??
?è±?????????????·??????????????????±????????????
×???S±í????????????±??¤??????·???????
×???C±í????????????±??¤?????????????????ù????????
????????1A. ????1B. ????1C.
3.1.2??TT????
TT system
???????????????±?????????è±???????????·????????????????????????????????????????? ×?????????×???T±í?????????????????±????????
??????×???T±í???è±???????????·???????????????????????????????????
????????2
??
3.1.3??IT????
IT system
????????????????·????????ò?¨??×è?????????????è±?????????????·?????????????
×?????????×???I±í???????????ù????????·????????ò?????¨??×è????????
??????×???T±í???è±???????????·???????????????????????????????????
????????3
??3.1.4???????????§???????? system with effectively earthed neutral
???????±???????ò????????×è???????????????¨???????ò?????????ò??????±????????ò????3????X0/X1????3??
???ò??×è?????ò??????±????????ò????1??R0/X1??1??
±??????????????ó???????÷??????
??3.1.5????????·????§???????? system with non-effectively earthed neutral
???????????????ò??????×è???????ò?????????????????¨??±??????????ò?????????ò??????±????ó??3??X0/X1?? 3?????ò??×è?????ò??????±???
?ó??1??R0/X1??1??
±??????????????????????÷??????
??3.2??°???????????
??3.2.1???ì?????? inspection earthing
???ì???è±??????·?±???????????????±???ì?????è±??????·????????·????ó??????????????·?????????????????
??3.2.2???¤×÷???? working earthing
???????·?ò?è±????????????ó??????????±????÷??????????????????
??3.2.3??±??¤???? protective earthing
°????????é??????????????????????????????????·????ó????????????????????????
??3.2.4?????????? iterative earth
±??¤???????????????ò?à???¨??????×°????????????????????????
??3.2.5?????????? fault earthing
???????ó???????????????±??????×è???????????????±????????????×??°?ê???????±??
??3.2.6????????×è resistance of an earthed conductorearthing resistance
±???????????????????????????????????????????×è??????????×è??????????????????????????×è???????????÷??×è??????
??3.2.7???????????ò?? earth fault current
?????¨???????á???????????????±(?????????????????à?ò?à?à????????)?????à?????????????¨??(??°????è±?°?×°??)?ê???à??????×????¤???????????????±?????¨???????¤?????????§????±???
??3.2.8?????????????÷ earth fault current
?÷?ò?ó???????????÷??
??3.2.9?????????·???÷ earth short circuit current
??????????????·??ú???·?????????÷??
??3.2.10????(??)?÷±??¤ overcurrent protection
???÷?????¤?¨???±????±??¤×°????×÷??????±??¤·?????
??3.2.11????(??)??±??¤ overvoltage protection
?????????¤?¨???±?????????????ò???????è±???????????????±??¤·?????
??3.2.12?????à±??¤ open-phase protection
?????à?à???·?????à?????????÷?????§??????±?±??¤?è±??ò?????à?à???????????à?ò???à?§????·???????????????±?±??¤?è±?????????±??¤·?????
??3.2.13???±??????·??¤???????¤×÷?±????·??¤???ù±?·??¤ protection against direct contact; protection against shock in normal service, basic protection
?????ò????????????·???????????·??¤??
??3.2.14??????????±??¤???????±????±??¤??????±??¤ protection against indirect contact; protection against shock in
the case of a fault; supplementary protection
?????ò??????????????·????????±??±???????????????????·?????????????±??¤??
??3.2.15???????????? equipotential bonding
?÷????????????·?????????????·??????????????à??????????????
??3.2.16??·??? dust-protected
·??????????????????????????????ú?·?ú?ú?????°?ì??·??¤??
??3.2.17??·??? protected against splashing
·???????·??ò???????????????????????????????ú?·?ú?ú?????°?ì??·??¤??
??3.2.18??·??? protected against dropping water
·??????±???????????????????????????????ú?·?ú?ú?????°?ì??·??¤??
??3.2.19??·????? protected against the effects of immersion
?±?????ú?·?????¨?????????±?????????????±????·??????????????????????????ú?·?ú?ú?????°?ì??·??¤??
??3.2.20??·??±?? protected against submersion
?±?????ú?·°????ì?§???¨???????¤???±???±???????í??????????????·??¤??
×??????????à?????????ú?·???°·??±???±?????????????????í??????????????????????????????????
??3.3??±??¤?è±???×°??
??3.3.1??°??????·??×°?? safety circuit and device
??·??????????????????????±???°???????????????è±????è???????·??×°????
??3.3.2??0?à?è±? class 0 equipment
?????ù±?????????·?????±??¤???????×???ü????????·?(?????????°)???è±????¨????????±??¤?????????????????????????ù±????????????é????±??????????§?·??????·??¤???è±???
??3.3.3???ò?à?è±? class ?? equipment
?????????ù±?????????·?????±??¤????????°ü?¨??????????°???????????°??×???°????????·????????è±????¨????????±??¤(????)???????????×???°??????·????ù±??????§?§?±???????á??????????·????è±???
??3.3.4???ò?à?è±? class ?ò equipment
?????????ù±?????????·?????±??¤????????°ü?¨??????°???????(?????????????ò????????)??????±??¤?????ò?????è±???????×÷???¨???è±???
??3.3.5???ó?à?è±? class ?ó equipment
????°???????????????????·?????±??¤?????????????ú?ú?????????á????°??????????????è±???
??3.3.6????(??)?÷±??¤×°?? overcurrent protective device
?????????÷???????·????????????????×°????
??3.3.7??(?ú????????×°????)?????÷ release (of a mechanical switching device)
??????·?±????ú???????????????ò±??????????ú???????????ú?????????????????÷????
??3.3.8??±??¤?????÷ protective relay
????????×é??±??¤×°???????????????ü?????????÷?à?á??×é??±??¤×°?????????????????÷??±??¤?????÷·???±?±??¤???ó???ì???é????°??¤?¨???ó??×÷??·?????±¨?????ò????????
??3.3.9??(???à??????)?????????÷ (single-phase neutral) earthing reactor
??????±????÷?????????????????????÷????????????·??ú?????±?????????????÷??
??3.3.10?????????· earthed circuit
???????ò????????????????????×é????
??3.3.11?????????? earthing switch
???????·??????·????ú???????????ü???????¨?±????????·????????????????÷(???????·???÷)?????????ó?ü???????????·???????????÷??
×????????????????????·???¨????
??3.3.12?????????? earthing conductor
???÷??????×??ò?÷????????????????????±??¤??????
??3.3.13???÷??????×?
?÷?????? main earthing terminalmain earthing bar
??±??¤??????°ü?¨?????????????????¤×÷??????????(?????????°)??????×°??????????×??ò????????
??3.3.14?????????·?÷ residual current circuit-breaker
???·?????????÷?????¤?¨???±??×?????×÷????????
??3.3.15???????ú?? interlocking device
?????????????÷?ò????????????±??¤???????÷?ò??????°????¨?????ò??×÷?ò·????ó??×÷???è?????ú???????ú????
??3.3.16??????×°?? arc-control device
?§??×??ú???????????????·????????????????°??ú?????¨????×°????
??3.3.17??°???????±????÷ safety isolating transformer
?¨???????à?±???????????ò??????????????????????×é????????×é????????·?????±????÷??????±????÷??????°????????????ò???????·?????÷?ò???ü?è±????????è??????
??3.3.18?????·?÷ circuit-breaker
?????¨????????·??????????·???????????÷?????????ù???¨??·????????·????(???????·)?????¨?????????¨?±????·??????÷???ú??????????
??3.3.19???????÷ fuse
?±???÷???????¨?????¨?±???ó?????ü±??í?ú?ú??????????????????·??????·?????·??
??3.3.20??±??×?÷ surge arrester lightning arrester
±??¤?????è±??????????????????????????????÷???????±????·ù????????×°????
??3.3.21??±??¤?????÷ capacitor for voltage protection
???????????·?????????????????????÷?????????????÷??
??3.3.22??°??????? safety safety switch
?????ü??????·????°???????????÷????
??3.3.23??±??¤???· protective circuit
??±??¤???????????????·?ò???????·??????·???
??3.3.24?????÷???· limited current circuit
???????????????????????????????????????ù?÷???????÷?????á·??ú?????????·??
??3.3.25??±??¤?????÷?????????????÷ protective current ??voltage?? transformer
????????????????±??¤×°????????×°???????÷???????????????÷??
??3.3.26???????à????±¨??×°?? insulation monitoring and warnign device
??????????×è?????±·?????????×°????
??3.3.27??±??¤???? protective conductor
????·?????±??¤?????ù???ó??????????????????·?×÷????????????????
a. ??????????·???
b. ??????????·???
c. ?÷??????×???
d. ????????
e. ???????????ò???¤????????
×?????????????·???PE±í????
??3.3.28?????????? neutral conductor
??????????????????????????????×÷??????????
×?????????????·???N±í????
??3.3.29??±??¤????????
PEN????
PEN conductor
??????????????±??¤????????????????????????
×???????×???PEN????±??¤??????·???PE????????????·???N×é??????????
??3.3.30???????????????? equipotential bonding conductor
???·±???????????????????±??¤??????
& K
????×°?? ............................................... 3.3.16
N
?????????? .................................................1.35
P
?????à?? ............................................... 2.2.3
P E N ???? ............................................. 3.3.29
?·???ò?? .............................................. 2.1.14
??????·??? ............................................ 1.6
T
T N ???? .............................................. 3.1.1
???±?????°??·? ........................................ 1.17
T T ???? ........................................ 3.1.2
W
??????????·? .......................................... 1.16
???? ................................................. 2.1.15
??????????·?1.15
X
???÷???· .............................................. 3.3.24
???????÷ ...................................................2.1.11
& W
. ???à?è±? ................................................... 3.3.3