Loop Tn - Tt - Uniks Rapid Pro Bedienungsanleitung

LOOP TT e TN
Z line - PE impedance measurement in TT system
Z: Global Earth Resistance
Vc: Contact Voltage
NOTA: Limit for earth ground resistance is defined as:
Rt ≤ Vc
Vc:Contact Voltage Limit (50V o 25V)
I∆n I∆n: Nominal RCD current
Impedance measurement Zs L-pe in TN system
Z: Fault Ground Impedance L-Pe
Ipsc: Prospective short circuit current (for check correct sizing of MCB or FUSE
protecting the system)
BT
BT
RCD
RCD
L
L
N
N
Pe
Pe
Re
Re
BT
BT
RCD
FUSE RCD
FUSE
L
L
N
N
Pe
Pe
TT SYSTEM
MT
MT
Rt
Rt
TERRA
TERRA
TN-S SYSTEM
MT
MT
Rt
Rt
11