????°??????????? GB 4776-84
1???ù±?????
??1.1??±?°??? fail-safe
??·????ú?·±??í?????????????è??????????
??1.2??????×??? nromal condition
?ù??????·??????????è???ù????????×?????
??1.3?????????? electric accident
?????÷???????????×?????????????????·???????±???ò?????ì???¨???è?????????è±????????????????????????°??????????±??¨???ó??????????
??1.4??????
???÷ electric shock
???÷?¨???????ò?????????????????í???ú?í?§????
??1.5???????????? injury due to electromagnetic field
????????????×÷?????ü??????????????????
??1.6????????·???
?é???÷?? disruptive discharge dielectric breakdown
?????????????????é???°??×é???é??????????×÷???????é?????????§?????ó??
??????·????±???????????????????????????ò???ü??????
??1.7?????· short circuit
?¨??±?????????×è?ò×è???????????ò???????????????·?????????é?????????????????????????ò????????????????????
??1.8?????????? insulation fault
??????×è??????????????
??1.9?????????? earth fault
?????????????????ò??????????×è±??????????¨????????????????
??1.10???????÷ overcurrent
???????¨???÷?????÷??
??1.11???????? overvoltage
???????¨????????????
??1.12???????? overload
???????¨????????????
??1.13????????·? conductive part
???????????????¨?????¤×÷???÷????·???
??1.14????????·? live part
?????????±±??¨?????????ò??????·????ü°ü?¨????????????°?????????°ü?¨±??¤????????(PEN????)??
×??????????????¨????×???????????
??1.15????????????·? exposed conductive part
?????è±???±????°????????·????ü???????±?????????????????é??????????????
×??????????é???????¨????????????·????????????????è±?????????·???±?????????????????·???
??1.16????????????·? extraneous conductive part
????????×°??×é????·????×????????(?¨??????????)????????·???
??1.17?????±?????°??·? simultaneously accessible parts
???????±???°???????ò??????·????ò?????????ù???????????±???°???????ò??????·???
×??????±?????°??·?????????
?? ??????·???
?? ??????????·???
?? ??????????·???
?? ±??¤??????
?? ????????
??1.18???±?????? direct contact
???ò????????????·?????????
??1.19?????????? indirect contact
???ò???????????é????±???????????????????·?????????
??1.20?????????? touch voltage
?????????±?????±?????°??·?????????????????
×????? °?????????????????????????????±??¤??????·?????
?? ???????é???????????????????????????°??????·???????×è?????÷?? ?°?ì??
??1.21?????????? step voltage
?????????????÷?÷?????ó????????????×?????????????
??1.22??°??????????? safety extra-low voltage(SELV)
??°???????±????÷?ò??????????×é??±??÷?÷?????????????????????·?????????????ò???????????????????????§????????50·ü?????÷??????
??1.23?????????? voltage to earth
?????????ó??????????????(?ó??????????)??
??1.24???????????? overvoltage to earth
????????????·???????(??????×???????????)????·???????±í??????????????
??1.25?????????÷ shock current
?¨???????ò???????????????????????í???ú?í?§?????÷?????÷??
??1.26??????(???÷)???? threshold of perception current
?????¨???????????÷?¨????????????????????????×??????÷????
??1.27??°???(???÷)???? threshold of let-go current
?????¨????????????×?????????????°?????×??ó???÷????
??1.28?????ü(???÷)???? threshold of ventricular fibrillation current
?????¨???????????????????????ü????×??????÷????
??1.29?????????÷
???????÷ fault current
???????????ò????±????????ì???????÷??
??1.30??(???·??)???????÷ overload current (of a circuit)
???????????????é???????·??·??ú???????÷??
??1.31?????·???÷ short-circuit current
?????·???????????????ì?????·?±?ù?ú?ú???????÷??
??1.32?????à???÷ residual current
??????×°???????????÷?????·???????????????????÷???±?????ú??????
??1.33??????×?×è?? total impedance of the human body
????????×è?????¤·?×è????????????
??1.34??°???×è?? safety impedance
????????????·????????°????????·???????×è?????????????è±???????????????·??ú???????é??????°????÷??????°????????????????è±??????????ü????±?????????????
??1.35???????????? fault withstandability
????×°?????????¨?????????????÷??×÷?????????????¨??????????????????
??1.36????°??????? unsafe temperature
??????????????(?ò)????????×÷????????????????????×÷????????
2???ù±?????
??2.1??????
??2.1.1?????? (????) insulation (property)
?????????ó?ù????????????????
??2.1.2??????(????) insulation (material)
?ù?????????÷??????????????
??2.1.3???????á?? insulation system
?????ò??????????????×é?????ù???????è±????????????????ó?????ü???????????è????????????????????????????????????????·???
×??????¨?????è±??????í?????????????????á????
??2.1.4???ù±????? basic insulation
??????·?????·????????ù±?±??¤×÷??????????
??2.1.5?????????? supplementary insulation
???????ù±????????????é????·????????????ù±?????????????????????????
??2.1.6?????????? double insulation
???±?????ù±???????????????????????
??2.1.7?????????? reinforced insulation
?à?±??????????±??¤???????????????á????
??2.1.8????????×è insulation resistance
?????????????????????????????????????¨??????????×è??
??2.1.9???é??????
?é?????? dielectric strenght
?????ù??????????????????????×?????????????
??2.1.10???é?????????é dielectric test
???????????????¨?????????ì?é????·?·??????ì?§?ù???¨?????·???¨?????????????±???é??
??2.1.11?????????÷ leakage current
?????????????é???????÷???ó???ò???·????????????·??????÷??
×????????÷????°ü?¨???????????????????÷????????????·?????
??2.1.12???é??????
?é?????? dielectric loss
???é?????±±??????ü????????????????????????????
??2.1.13????????(???????¨???é????)
loss angle (under sinusoidal condition)??????????????????????????????????±???????
??2.1.14???·???ò??
Q?ò?? quality factor
????????????????????????????±???
??2.1.15?????? enclosure
???è±??????????????°?ì??????·??ò???±????????·??¤×÷??????????
??2.1.16??·??¤?? protective cover
??·???????????????·??ú???????????ù?á??????????????·??ò??°???
??2.1.17?????? barrier
?????????????ü??·??ò???±????????·??¤×÷??????????
??2.1.18??×è???? obstacle
·????????????±????????????·????????????±??????????????
??2.2?????à
??2.2.1?????????? clearance
????????·?????×????±???à????
??2.2.2??±??¤???? protective gap
??????·?????????????????????·??ú×??ó??????????????
??2.2.3???????à?? creepage distance
????????????·???????????????±í????×????à????
???????????à??
??2.2.4?????? to isolatea.
???????÷???ò???·???í?????÷???ò???·?ê????????
b. (????????°ì·¨)?á?????????¨??·??¤???????????????????????·??
??2.2.5??°????à?? safe distance
????·??????????°?ò???ü????????·????????ò???ü??????×??ò???ü?????????ì?????????????????ù?è±????????¨?????à????
??2.2.6???ì±?·??§ arms reach
?????????????????ò×?????±í???????????????????????????è??°??ú???é??????????·??ò???ù??????????????????·??§??
??2.3?????÷??
??2.3.1??(??????)(????)???÷?? (continuous) current-carrying capacity (of a conductor)
?????¨?????????????????????????????????????¨???????????¨????×??ó???÷??
??2.4??±ê??
??2.4.1??°???±ê?? safety marking
??°?????????????????????·???????×???????±ê????????±í?????¨??°?????????
??2.4.2??????±ê??supplementary marking
±?????°???±ê?????±????????°???±ê????????×????÷??±ê????
??2.4.3??°????? safety colour
±í??°?????????????????±í?????????????????????á??????
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
???·±???????????????????±??¤??????
????????A
±ê ×? ?? ?? ?? ?÷
(??????)
A.1??±?±ê×??????????????ù?í????????
A.2??±?±ê×?????????????????????????????????????????????????????·???????????
???????????????????????°??
A.3??±?±ê×???·??¨????????????·¨????·??¨???????????ú?????°????????????×é???í
????????
A.4??±?±ê×??????¨??( )????·¨??
??A.4.1???????¨????±????¨?????????????????????????????¨???°???????????ò????
?????ò????
A.4.2???¨??????????±í?????????ò?????????????÷??
A.4.3???¨??????????±í????????????·??§??
A.5??±?±ê×????ù???????????????????÷?¨???????ù????????·???????×?·??????????ú
??±ê×???·??±???ò????·?????×÷??±ê×?????????
?? ?? ?÷ ??
A
IT???? ............................................ 3.1.3
°???±ê?? .......................................... 2.4.1
°??????·??×°?? ....................................... 3.3.1
°???????±????÷ ........................................ 3.3.17
°????à?? ........................................ 2.2.5
°??????? ....................................... 3.3.22
°????? .............................................. 2.4.3
°??????????? .......................................... 1.22
°???×è?? ............................................. 1.34
B
°???(???÷)???? ....................................... 1.27
±?°??? ............................................... 1.1
±??¤???? ............................................. 3.3.27
±??¤???· ............................................ 3.3.23
±??¤?????÷ .......................................... 3.3.21
±??¤?????÷ ............................................ 3.3.8
±??¤???? ............................................. 2.2.2
±??¤???? .............................................. 3.2.3
±??¤?????÷?????÷ ..................................... . 3.3.25
±??¤???????????÷ ....................................... 3.3.25
±??¤???????? .......................................... 3.3.29
±??×?÷ ................................................. 3.3.20
????±ê?? ............................................... 2.4.2
??°??????? ............................................. 1.36
& B
???à???÷ ..................................................1.32
???? .....................................................1.4
???????÷ ..................................................1.25
???????? ..................................................3.2.4
& B
??????·? ..................................................1.14
(???à??????) ?????????÷ ...................................3.3.9
??????·? ................................................. 1.13
(??????) (????) ???÷?? ....................................2.3.1
?????????? ................................................3.2.15
?????????????? .......................................... .3.3.30
?????????? .............................................. 1.5
???÷ .................................................... 1.4
(???·??) ???????÷ ........................................ 1.30
???????? .................................................2.2.1
???????? ................................................. 1.3
???· .....................................................1.7
???·???÷ ................................................. 1.31
???·?÷ ................................................. 3.3.18
???à±??¤ ............................................... 3.2.12
???????? ............................................... 1.23
?????????? .......................................... 1.24
& D
?ò?à?è±? ............................................ 3.3.4
F
·??? ............................................... 3.2.16
·??? ............................................... 3.2.18
·??¤?? ................................................. 2.1.16
·??? ................................................ 3.2.17
·??±?? ................................................. 3.2.20
·????? ............................................... 3.2.19
????±??¤ .............................................. 3.2.14
???????? .............................................. 2.1.5
G
????(???÷) ???? ........................................ 1.26
???? .................................................. 2.2.4
?¤×÷???? ............................................... 3.2.2
???????÷ ............................................... 1.29
????????.................................................. 3.2.5
?????±????±??¤ .......................................... 3.2.14
?????÷ ................................................. 1.10
?????? .................................................. 1.11
?????? ................................................. 1.12
?? (??) ?÷±??¤ .......................................... 3.2.10
?? (??) ?÷±??¤×°?? ...................................... 3.3.6
????±??¤ ............................................... 3.2.11
J
?ù±?·??¤ ............................................... 3.2.13
?ù±????? ................................................ 2.1.4
(?ú????????×°????) ?????÷ ................................. 3.3.7
???????? ................................................. 2.1.7
???????? ................................................ 1.19
????????±??¤ ............................................ 3.2.14
?ì?????? .............................................. 3.2.1
???????? ....................................................1.20
????????. ................................................. 3.3.12
???????· ............................................... 3.3.10
??????×è ............................................... 3.2.6
???????·???÷ ........................................... 3.2.9
???????? ............................................. 1.9
???????????÷ ........................................ 3.2.8
?????????ò?? ........................................... 3.2.7
???????? ......................................... 3.3.11
?é?????? ............................................. 2.1.9
?é?????? .............................................. 2.1.12
?é???÷?? ............................................. 1.6
?é?????? ........................................... 2.1.9
?é?????????é ....................................... 2.1.10
?é?????? ........................................... 2.1.12
???? (????) ......................................... 2.1.2
??????×è ........................................... 2.1
???????? ............................................ 1.8
?????à????±¨??×°?? ................................... 3.3.26
?????á?? ................................................ 2.1.3
???? (????) .......................................... 2.1.1
K
???????? ........................................... 1.21
& K
0?à?è±? ................................................ 3.3.2
?????ú?? ................................................. 3.3.15
?????à?? ..................................................2.2.3
???????·?÷ .............................................. 3.3.14
& K
????×°?? ............................................... 3.3.16
N
?????????? .................................................1.35
P
?????à?? ............................................... 2.2.3
P E N ???? ............................................. 3.3.29
?·???ò?? .............................................. 2.1.14
??????·??? ............................................ 1.6
Q
Q?ò?? ................................................. 2.1.14
& P
????×?×è?? ............................................. 1.33
?????÷ ................................................... 3.3.19
& R
?ó?à?è±? ............................................... 3.3.5
?ì±?·??§ .................................................. 2.2.6
???????÷ .................................................1.29
???????? ........................................... 2.1.6
?????? (???????¨???é????) ................................ 2.1.13
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
Z
???? .................................................... 2.1.17
?????¤×÷?±????·??¤ ..................................... 3.2.13
????×??? ............................................... 1.2
?±??????.................................................. 1.18
?±??????·??¤ ............................................. 3.2.13
???ü (???÷) ???? ........................................ 1.28
???????? ................................................. 3.3.28
??????·????§???????? .................................... 3.1.5
?????????§???????? ....................................... 3.1.4
?÷??????×? ............................................... 3.3.13
?÷?????? ................................................. 3.3.13
×è???? ............................................. 2.1.18
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