62271-200 (CDV stage)prepared by SC17C / MT14
proposes a "user-oriented" classification
make internal arc test an optionnal type test (no more with agreement between manufacturer and user)
main changes
current carrying capability demonstation of the enclosure and the metallic partitions (if any)
no more "cubicle, compartimented, metalclad" designations, but
"Service Continuity" and "Partition" classes
optionnal "internal arc" class
Situation according to 17C/283/CDV
Reliability due to some protection of equipment against environmental influences
Personnel electrical & mechanical safety in normal operation & in case of insulating deficiency
IEC 62271-200
Fully enclosed in metallic envelope having some current carrying capability
(30 A DC : U< 3V)
Situation according to 17C/283/CDV
service continuity during maintenance
IEC 62271-200 : Fully enclosed in metallic envelope having some current carrying capacity
Reliability due to some protection of equipment against environmental influences
Personnel electrical & mechanical safety in normal operation & in case of insulation failure
Service Continuity Class
Internal Arc Class IAC
Classification based on consequence of internal arc on personnel safety
Personnel safety in case of internal arc
Partition Class
Insulating / Metallic
Classification based on electrical field presence in safe access compartment
Personnel comfort during maintenance
Situation according to 17C/283/CDV
SC2A class plus :
SC 2 B class
Maintainability of defined parts with no need of cable disconnection (separated cable compartment with disconnection)
Maintainability of one functionnal unit allowing normal service of remaining units of the switchboard (busbar in a separate compartment)
Several levels of service continuity during maintenance
IEC 62271-200 : Fully enclosed in metallic envelope having some current carrying capacity
Service Continuity Class
Metal enclosed not of SC2 class
SC 1 class
class M
All partitions and shutters of safe access compartment shall be metallic with some current carrying capacity
IEC 62271-200 : Fully enclosed in metallic envelope having some current carrying capacity
Personnel comfort during maintenance
Partition Class
Classification based on electrical field presence in safe access compartment
class I
Partitions or shutters may be partially or totally of insulating material
electrical and mechanical safety according to 60466 or 60137
Situation according to 17C/283/CDV
IAC not classified
IEC 62271-200 : Fully enclosed in metallic envelope having some current carrying capacity
IAC classified
No ignition of indicators
Demonstrated by type test
Internal Arc Class
Classification based on consequense of internal arc on personnel safety
Personnal safety in case of internal arc
no test performed to assess behaviour under arc conditions
Situation according to 17C/283/CDV
either "controlled access" with interlocks
or "procedure based access"
pressure withstand tests of gas-filled compartments
applicable also to compartments with built-in pressure relief devices (as SM6 switch compartment)
tests on earthing circuits
restricted to circuits intented to carry fault currents without any fault within the functionnal unit
passing-through earthing bars
tests on insulating partitions with bushings are better defined
IEC 62271-200 : Fully enclosed in metallic envelope having some current carrying capacity
Situation according to 17C/283/CDV
service continuity class : SC2A
one accessible compartment is the cable (or cable and fuses) compartment
this compartment is accessible with the busbar energised
partition class : I
switch compartment has insulating partitions, as well as other compartments
these partitions have embeded bushings and have to be designed according to 5.103.3.3 and tested to 6.105 :
dielectric withstand of the partition material
dielectric withstand of the gas to the internal face (with the bushings earthed)
controlled access
breaker compartment is accessible with both busbar and cables energised
accessibility :
partition class : M
questionnable IP for the closed shutters...