33Symmetra MW II 1200 kW 3 × 400/230 V Installation - 990-1979E-001
Residual Current Sense
Mains - input UPS - output
PE
N
PE
PE
PE
Bypass - input Bypass - output
L1
L3
L2
L1
L3
L2
N
L1
L3
L2
L1
L3
L2
( Alternative to earth electrode )Earthing Conductor
Main Protective Earthing Terminal
External SSW-Bypass
Symmetra MW
( PDU )
Service Entrance
Main
inverter
u
uuM
Main Protective Earthing Terminal
N
PE
Q1
Q6
Q3
Q5
Earthing arrangements and protective conductors - Symmetra MW in "IT - installation"
E
Residual current protective devicecan be used.+- +-
Battery 1
Battery 2
Q7 Q8
Battery 1 Battery 2
PE
PE
Battery
rack
Battery
breaker
box
Q4
Delta
Inverter
i
i
i
Common-mode filter
Switchgear
See: IEC 60364-4-41 § 413.1.5
Protective Earthing Conductor
Insulation
Monitoring
Device
Requirement !!IEC 60664-4-41 § 413.1.5.4Suitable earth electrode: RA x Id < 50VWith reference to IEC 60364-4-41 § 413.1.5.3Alternative:The exposed-conductive-parts can be earthed individually or in groups.But special demands are required. See IEC 60364-4-41 § 413.1.5.5 a)