Fuji Electric EW32EAG - Page 37

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3
Selection and application
3-1 Selection check points
Table 3-1 Systematic MCCB selection
Check point Check points for system
designing
Check points for circuits
and protective equipment
Check points for MCCBs Specifications of MCCBs
Power supply capacity
Power supply system
Total load capacity Short-circuit current Icu
Series
Frame size
Power supply voltage
(AC, DC, frequency)
Load voltage Rated voltage (Ue)
No. of circuit wires
No. of poles
Wires and equipment
connected in series
• Mechanical allowable
characteristics
• Thermal allowable
characteristics
Wire sizeLoad current
Breaking characteristics
Series
Frame size
Operating
characteristics
Rated current (In)
Load current-time
characteristics
Load types
Main circuit
Branch circuit
Installed location
Protected equipment
types (Wires, loads)
Types by use
Line protection
Motor protection
Instantaneous trip type
Switching
frequency
Operating method
(Remote, manual)
Operation
Operating durability
Operating device
Accessories
Motor driven (M)
External operating
handle (V, N)
Shunt trip (F)
Undervoltage trip (R)
Auxiliary switch (W)
Alarm switch (K)
Installation and
connection method
Switchboard constructionInstallation and
connection
Front mounting,
front connection
Front mounting,
rear connection (X)
Plug-in (P)
Line side or load side
protective device
• Breaking
characteristics
• Operating
characteristics
Breaking
characteristics
Operating
characteristics
Operating
characteristics
Selective trip
coordination
Power supply
reliability
Cascade (back up)
trip coordination
Allowable characteristics
of load side protective
devices
Main MCCBs
Branch MCCBs Operating
characteristics of line
side protective devices
Economical use
Allowable
characteristics
Series
Frame size
Rated current (In)