Installation manual

System earthing arrangements >
34020846EN/AE - Page 24
1. Installation
1.4 System earthing arrangements
This section lists the main SEAs (system earthing arrangements) and their wiring requirements.
For SEAs not listed here, please contact the technical support department.
Single UPS
TNS upstream, TNS downstream
For separate normal and bypass AC lines from a single source.
Without residual-current protection:
With residual-current protection:
UPS units used as frequency converters: please contact your technical assistance.
Galvanic isolation between the normal and bypass AC lines is mandatory.
The recommended minimum residual current protection is 3A, provided the conditions defined in IEC364.4-41 are
respected.
For a transformer on a Bypass AC network
For a transformer on a Normal AC network
Adding a transformer into the Normal AC network reduces the installation's overall efficiency.
Bypass AC
Normal AC
L1
L2
L3
L1
L2
L3
N
L1
L2
L3
N
Load
PE
SS
UPS
PFC
INV
PE
MLVS
PE
Bypass AC
Normal AC
L1
L2
L3
L1
L2
L3
N
L1
L2
L3
N
(4p)
Load
PE
SS
UPS
PFC
INV
PE
PE
MLVS
Bypass AC
Normal AC
L1
L2
L3
L1
L2
L3
N
L1
L2
L3
N
Load
PE
SS
UPS
PFC
INV
PE
MLVS
PE