HT instruments MACROTEST G3 - Manual (Page 35)

MACROTESTG3 - COMBIG3
EN - 34
The following table summarizes the possible measures executable depending on the type of
system (TT, TN and IT), of selected modes and the relationships that define limit values
TT TN IT
Mode Condition x OK outcome Condition x OK outcome Condition x OK outcome
L-L
STD No outcome No outcome No outcome
kA Isc L-L max < BC Isc L-L max < BC Isc L-L max < BC
I 2 t (Isc L-L 3F) 2 * t < (K * S) 2 (Isc L-L3F) 2 * t < (K * S) 2 (Isc L-L3F) 2 * t < (K * S) 2
(IscL-Lmin 2F) Tmax  Tmax < Tlim (IscL-L min 2F) Tmax Tmax < Tlim (IscL-Lmin 2F) Tmax  Tmax < Tlim
L-N
STD No outcome No outcome No outcome
kA Isc L-N max < BC Isc L-N max < BC Isc L-N max < BC
I 2 t (Isc L-N) 2 * t < (K * S) 2 (Isc L-N) 2 * t < (K * S) 2 (Isc L-N) 2 * t < (K * S) 2
(Isc L-N min ) Tmax  Tmax < Tlim (Isc L-N min ) Tmax  Tmax < Tlim (Isc L-N min ) Tmax  Tmax < Tlim
L-PE
STD No outcome
kA Isc L-PE max< BC
I 2 t (Isc L-PE) 2 * t < (K * S) 2
(Isc L-PE min ) Tmax  Tmax < Tlim
Tlim  Ia  Isc L-PE MIN > Ia Utmeas < Utlim
Ra
(No for
IMP57)
STD
kA
I 2 t
(Rameas * Idn) < Utlim Isc L-PE MIN > Idn
Table 2: Conditions of positive outcome depending on the test parameters
Where:
Empty cells Not available mode for this particular combination of electric system
Isc L-L_3F Prospective short circuit current three-phase Phase-Phase (see § 12.5)
Isc L-L_Min2F Prospective short circuit current minimum two-phase Phase-Phase (see § 12.9)
Isc L-N_Max
Prospective short circuit current maximum Phase-Neutral (see § 12.5)
Isc L-N_Min Prospective short circuit current minimum Phase-Neutral (see § 12.9)
Isc L-PE_Max Prospective short circuit current maximum Phase-PE (see § 12.5)
Isc L-PE_Min
Prospective short circuit current minimum Phase-PE (see § 12.9)
BC Breaking Capacity of the protection device - kA)
K Constant relative to the I2t measurement (vedere § 12.10)
S Section of conductor
Tmax Maximum trip out time of the protection device
Tlim Limit time of fault extinction by the protection set by the user
Ut meas Contact voltage measured
Ut lim Contact voltage limit (25V or 50V)
Ra meas Global earth resistance measured
Idn Trip out current of RCD devices
6.4.2. STD Mode – Generic test