MarelliMotori D-Vo Light Manuel D'utilisation page 65

Operation in parallel with grid – inaccurate, unstable or missing regulation power (or reactive power) factor
regulation.
Step 1 Check whether the PF (or VAR) mode is enabled: if the control system issues the closing command for
the PF/VAR contact (C6 by default), in the Monitor area of D-Vo Dashboard, the PF/VAR LED must be
on.
If the PF (or VAR) mode is enabled, move to Step 2.
Otherwise, check whether the PF/VAR contact is working properly by following the procedure described
below:
1. fully disconnect D-Vo from the remainder of the system;
2. insert a jumper between C6 and M, then power D-Vo from an external source, in accordance with
the specifications;
3. check the colour of the PF/VAR LED.
If:
•
the LED is off: move to Step 10.
•
the LED is on: the PF (VAR) mode is properly enabled when the PF/VAR contact is closed; therefore
you need to check for the proper operation of the control system of the PF/VAR contact (a
component not supplied by Marelli).
Step 2 Use D-Vo Dashboard to check the settings; in particular, check:
•
The generator rated data.
•
The parallel operation options selected.
•
The sensing settings.
•
The setpoint settings.
Edit any incorrect settings.
Otherwise, move to Step 3.
Step 3 Check that the current transformer (CT) is not short-circuited or disconnected.
Modify any incorrect connections.
Otherwise, move to Step 4.
Step 4 Check whether the CT is properly connected.
Try inverting the CT connection on the terminals of the current input in use (I3+/I3- by default).
If the above operation has no effect, restore the previous connection and move to Step 5.
Step 5 Check that the voltage and current measurements set in D-Vo Dashboard match the measurement
connections physically existing on D-Vo.
Modify any incorrect connections and/or settings.
Otherwise, move to Step 6.
Step 6 Use D-Vo Dashboard to check the regulation stability setup.
If needed edit the settings until obtaining the desired precision, stability and response.
Otherwise, move to Step 7.
Step 7 Use D-Vo Dashboard to verify whether the PF (VAR) setpoint has been modified by one of the analogue
inputs, if in use.
Check that the values at the analogue inputs are read properly and that they are consistent with the
application requirements.
If the PF (VAR) setpoint has been modified by an analogue input, check the analogue input control
system (a component not supplied by Marelli Motori).
Otherwise, move to Step 8.
Step 8 Check whether the PF (or reactive power) set point has been improperly modified by the digital inputs
RAISE (C3 by default) and/or LOWER (C4 by default), or if the same inputs are not properly controlled.
In particular:
1. with the generator stopped, disconnect the cables connected to C3 and C4;
2. synchronise the generator with the grid and measure the PF (or reactive power).
If the measured value of PF (or reactive power) matches the set one, check for the proper operation of
the RAISE and/or LOWER contact control system (a component not supplied by Marelli).
Otherwise, move to Step 9.
Step 9 Check whether the overexcitation (or underexcitation) limiter has tripped.
If one of the limiters has tripped, check that the limitation settings are consistent with the characteristics
of the machine and of the applications.
Edit any incorrect settings.
Otherwise, move to Step 10.
Step 10 Replace the regulator.
9638571A0_C
D-Vo Light – Marelli Motori
EN 65