HT Italia IMP57, User Manual

Page: 25 / 39

IMP57
EN - 23
6.3.2. Prospective Short Circuit Current Calculation
The instrument calculated the Prospective short circuit current as:
Connection
Phase - Phase
(P-P)
2
3
3
HOT
P P
NOM
P P
MIN ph MIN
Z
U
C I


 
Three Phase Minimum Prospective Short Circuit Current
2
3
3
P P
NOM
P P
MAX ph MAX
Z
U
C I


 
Three Phase Maximum Prospective Short Circuit Current
HOT
P P
NOM
P P
MIN ph MIN
Z
U
C I


 
2
Two Phase Minimum Prospective Short Circuit Current
P P
NOM
P P
MAX ph MAX
Z
U
C I


 
2
Two Phase Maximum Prospective Short Circuit Current
Phase - Neutral
(P-N)
HOT
N P
NOM
N P
MIN N P MIN
Z
U
C I



 
Single Phase Minimum Prospective Short Circuit Current
N P
NOM
N P
MAX N P MAX
Z
U
C I



 
Single Phase Maximum Prospective Short Circuit Current
Phase-Protection conductor
(P-PE)
HOT
PE P
NOM
PE P
MIN PE P MIN
Z
U
C I



 
Fault to Ground Minimum Prospective Short Circuit
Current
PE P
NOM
PE P
MAX PE P MAX
Z
U
C I



 
Fault to Ground Maximum Prospective Short Circuit
Current
Generic
MIS
NOM
STD
Z
U
I

Generic Prospective Short Circuit Current
where:
2 2
) 5 . 1 (
X P X P
HOT
X P
X R Z
  
  
X= P, N, PE
and
Voltage U
NOM
C
MIN
C
MAX
230V-10% < Vmeasured < 230V+ 10% 230V 0,95 1,05
230V+10% < Vmeasured < 400V- 10% Vmeasured 1,00 1,10
400V-10% < Vmeasured < 400V+ 10% 400V 0,95 1,05