Functional Description; Introduction; Operating Modes; Digital Inputs - MarelliMotori D-Vo Light Manuel D'utilisation

5. FUNCTIONAL DESCRIPTION

5.1.

INTRODUCTION

The following section provides a short description of the functions implemented by the D-Vo regulation system.
Before using D-Vo on any generator, carefully read and understand all the provisions contained in these
documents. Should you need any further information, please contact Marelli Motori Services.
5.2.

OPERATING MODES

D-Vo can be used in the following operating modes:
1. AVR mode: D-Vo regulates the generator voltage.
2. FCR mode: D-Vo regulates the generator exciter stator current.
3. PF mode: D-Vo regulates the power factor.
4. VAR mode: D-Vo regulates the reactive power.
5.3.

DIGITAL INPUTS

D-Vo provides 9 input contacts for the operating control of the regulation.
The following is a description of the functions associated with these contacts.
The circuit including the digital inputs is classified in isolation class II, with reinforced isolation, equivalent
to double isolation.
The reference voltage is SELV - Safety Extra-Low Voltage.
WARNING:
D-Vo CAN BE PERMANENTLY DAMAGED IF VOLTAGE IS APPLIED TO THE CONTACT
TERMINALS, DUE TO AN INCORRECT CONNECTION OR (POTENTIALLY) TO NOISE PICKED UP
BY THE CONNECTION CABLES.
More in detail, YOU NEED TO AVOID ANY VOLTAGE PEAKS EXCEEDING 12V.
In case of doubts as to the peaks on the contact terminals due to noise, the user shall install dry contacts
(relays) near the regulator (distance ≤ 50cm).
Even if suitable, the wiring between the dry contacts and the D-VO shall not exceed the length of 2m.
A suitable wiring is a wiring consisting of shielded and twisted cables; for further instructions refer to
Chapter 3.
INPUT CONTACT
START C1 (default)
STOP C2 (default)
9638571A0_C
DESCRIPTION
Excitation state contact (normally open, switch logic): after this contact closes, D-
Vo supplies power to the exciter field as long as the contact remains closed.
When the contact opens, the power supply to the exciter field shall be cut off.
If START is closed and the temporary STOP contact closes (see the next input),
the START state is disabled even when the relevant contact is closed; to restore
the excitation, you need to release STOP, then open and close back START.
The START contact can be associated with the de-excitation contact.
IMPORTANT NOTE: START has an operating function; as a consequence, it
cannot be regarded as a replacement of any safety and/or emergency contacts.
Excitation stop state contact (normally open, push-button logic):
after this contact temporarily closes, the D-Vo stops supplying power to the exciter
field, locking it to the minimum value (zero).
Once the stop command is issued, D-Vo no longer supplies power to the exciter
and the push-button can be released. This input has priority over the START
contact.
If START is closed and the STOP contact closes, on a jog or continuous basis,
the START state is disabled even when the relevant contact is closed; to restore
the excitation, you need to release STOP, then open and close back START.
D-Vo Light – Marelli Motori
EN 24