HT instruments MACROTEST G3 - Manual (Page 100)

MACROTESTG3 - COMBIG3
EN - 99
CAUTION
The instrument must be used to measure fault loop impedance values at
least 10 times higher than the resolution value of the instrument in order to
minimize errors.
Depending on the set values of nominal voltage (see § 5.1.3) and the measured value of
fault loop impedance, the instrument calculates the minimum value of the assumed short-
circuit current to be interrupted by the protection device. For proper coordination, this value
MUST always be greater than or equal to the Ia value of the tripping current of the type of
protection considered.
The Ia reference value depends on:

Protection type (curve)
 Rated current of the protection device
 Time of fault extinction by the protection
The instrument allows the selection of the following parameters:

MCB current (B curve) selectable among values:
6, 10, 13, 15, 16, 20, 25, 32, 40, 50, 63A
 MCB current (C, K curves) selectable among values:
0.5, 1, 1.6, 2, 4, 6, 10, 13, 15, 16, 20, 25, 32, 40, 50, 63A
 MCB current (D curve) selectable among values:
 0.5, 1, 1.6, 2, 4, 6, 10, 13, 15, 16, 20, 25, 32A
 Nominal current Fuse gG selectable among values: 2, 4, 6, 8, 10, 12, 13, 16, 20, 25, 32,
40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1000, 1250A
 Nominal current Fuse aM selectable among values: 2, 4, 6, 8, 10, 12, 16, 20, 25, 32, 40,
50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630A
 Time of fault extinction by the protection selectable among: 0.1s, 0.2s, 0.4s, 5s