MarelliMotori MEC-100 Manuel De L'utilisateur page 63

For applications with supply voltages higher than 480Vac ± 15% a step-down transformer must be interposed, with rated
secondary voltage included in the ranges indicated in the relevant specifications. The only single-phase connection
configuration is provided. This input is internally insulated.
3.4.4. Analogue Auxiliary Inputs (E1-E2-M)
The MEC-100 is provided with two auxiliary inputs to control the voltage, power factor, reactive power and excitation current
setpoints by means of an external device (1
These inputs can be used by applying a 4-20mA current and they can be individually associated to two regulation Modes. To
the control current range corresponds the range established during set-up for the relative associated setpoint (see Par. 5.7.3).
For example, if voltage setpoint limits are set to 80 and 120% of the generator rated voltage, 4mA will be
associated to the minimum limit (80%) and 20mA to the maximum limit (120%), and all the intermediate values of
the generator voltage setpoint will proportionally correspond to the current values between 4 and 20mA.
WARNING: THESE INPUTS ARE NOT INTERNALLY INSULATED. The external device to which these inputs
should be connected must be equipped with a galvanically insulated output.
3.5. INPUT CONTACTS
The MEC-100 is equipped with 8 input contacts for the operational control of the regulation modes. Here below the description
of the functions related to these contacts is provided.
WARNING: THESE INPUTS ARE NOT INTERNALLY INSULATED. The external device to which these inputs
should be connected must be equipped with a galvanically insulated output.
WARNING: MEC-100 CAN BE PERMANENTLY DAMAGED IN CASE OF VOLTAGE APPLIED TO THE
CONTACT TERMINALS, E.G. (BUT NOT EXCLUSIVELY) DUE TO INTERFERENCES ENTERING THE
CONNECTIONS. In detail, it is compulsory to avoid voltage peaks higher than 40V.In case of doubt about
interference peak values on the contact terminals, the user is bound to install dry contacts (relays) near to the
regulator (distance
must not be longer than 2m.
3.5.1. START (C1 Contact)
Excitation start contact (normally open, switch logic): when this contact is closed, the MEC-100 supplies power to the exciter
field and continues to do so until the contact remains closed. When this contact is opened, the power supply to the exciter field
is stopped. If the excitation is present (START contact closed) and the temporary STOP contact is closed (see Par. 3.5.2), the
START contact is disabled and to supply the excitation power again it is necessary first to open and then re-close the START
contact (with STOP opened). When the START contact is closed, the LED corresponding to the Excitation State item in the
system status window in System Monitoring becomes green.
WARNING: START CONTACT MUST NOT BE CONSIDERED OR USED AS EMERGENCY AND/OR SAFETY
DEVICE. START contact has only an operating function, it can not be considered or used as emergency and/or
safety device.
3.5.2. STOP (C2 Contact)
Excitation stop contact (normally open, momentary pushbutton logic): when this contact is temporarily closed, the MEC-100
stops the power supply to the exciter field. When the stop command is given, the MEC-100 does not supply the exciter field e
the contact can be left again. This input is priority to the START contact. If the excitation is present (START contact closed) and
the temporary STOP contact is temporarily closed, the START contact is disabled and to supply the excitation power again it is
necessary first to open and then re-close the START contact (with STOP opened). When the STOP contact is closed, the LED
corresponding to the Operating Status item in the system status window in System Monitoring (see Par. 5.8.2) turns off. STOP
can be associated to the de-excitation (shutdown) contact (see Par. 3.12).
WARNING: STOP CONTACT MUST NOT BE CONSIDERED OR USED AS EMERGENCY AND/OR SAFETY
DEVICE. STOP contact has only an operating function, it can not be considered or used as emergency and/or
safety device.
963857137_M
st
In.: terminals E1-M; 2
≤
50cm); suitable cabling (shielded and twisted cables) between dry contacts and MEC-100
nd
In.: terminals E2-M).
MEC-100 – Marelli Motori
63