MarelliMotori MEC-100 Manuel De L'utilisateur page 88

Generator VT: present in the applications with generator voltages higher than 500V, which need a step-down transformer
between generator and MEC-100 sensing terminals.
❑
Primary Voltage (V): enter in this field the primary voltage value of the TV used (100 to 22000V, with minimum increase of
1V).
❑
Secondary Voltage (V): enter in this field the secondary voltage value of the TV used (100 to 500V, with minimum increase
of 1V).
If the generator voltage value is lower than 500V, the use of a step-down transformer may not be necessary:
therefore, the MEC-100 is directly connected to the mains terminals. In this case, in both the Primary and
Secondary Voltage fields the same value, equal to the predefined rated value, should be entered.
Line VT: present in the applications with network (Line) voltages higher than 500V, which need a step-down transformer
between the network and MEC-100 sensing terminals.
❑
Primary Voltage (V): enter in this field the primary voltage value of the TV used (100 to 22000V, with minimum increase of
1V).
❑
Secondary Voltage (V): enter in this field the secondary voltage value of the TV used (100 to 500V, with minimum increase
of 1V).
If the network voltage value is lower than 500V, the use of a step-down transformer may not be necessary:
therefore, the MEC-100 is directly connected to the network terminals. In this case, in both the Primary and
Secondary Voltage fields the same value, equal to the predefined rated value, should be entered.
Generator CT: makes the generator current sensing.
❑
Primary Current (A): enter in this field the primary current value of the CT used (1 to 10000A, with minimum increase of 1A).

Secondary Current (A): select in this field the secondary current value of the TA used by choosing between the two
standard values: 1A and 5A.
Calibrations: this set of parameters allows to calibrate the MEC-100 sensing function in case of non-ideal transformation ratios;
in this way the correct voltage, current and phase values are guaranteed to both the regulation and monitoring areas.
❑
Generator VT Ratio (%): if the MEC-100 Interface System senses and displays a generator voltage value higher, of a given
percentage, than the actual value, you need to add this percentage to the percentage already entered in the field (100% of
default), to obtain a correct and accurate sensing calibration (95 to 105%, with minimum increase of 0.1%).
❑
Line VT Ratio (%): if the MEC-100 Interface System senses and displays a network voltage value higher, of a given
percentage, than the actual value, you need to add this percentage to the percentage already entered in the field (100% of
default), to obtain a correct and accurate sensing calibration (95 to 105%, with minimum increase of 0.1%).
❑
Generator CT Ratio (%): if the MEC-100 Interface System senses and displays a generator current value higher, of a given
percentage, than the actual value, you need to add this percentage to the percentage already entered in the field (100% of
default), to obtain a correct and accurate sensing calibration (95 to 105%, with minimum increase of 0.1%).
❑
Phase Compensation (degrees): if the MEC-100 Interface System senses and displays a power factor value higher or lower
than the actual value, you need to introduce a compensation angle (0° default value), to obtain a correct and accurate
power factor measurement (-10° to +10°, with minimum increase of 0.1°).
❑
Excitation current measurement offset: should the excitation current reading by MEC-100 be incorrect, increase or
decrease the Offset value until the displayed measurement is correct.
963857137_M
Fig. 5.7.2.a
Sensing Parameter Area
MEC-100 – Marelli Motori
88