MarelliMotori MARK V Manual Del Usuario página 24

Setup of the Corner Frequency.
U/F
It is usually set at the factory in order to reduce the excitation when speed becomes
lower than 90% of rated speed at 50 Hz (frequency lower than 45 Hz, or corner
MIN MAX
frequency). By removing the bridge which normally shorts the terminals Hz and 60, the
speed protection operates properly for 60 Hz operation mode.
Turn clockwise to increase the operation frequency threshold
Setup of regulation stability.
STAB
The regulation can be set on the field to adapt it to the characteristics of the plant and
the driving engine (diesel engine, water turbine, gas turbine) in order to obtain the best
MIN MAX
voltage response. To change the stability characteristics of the regulator, the
potentiometer STAB must be adjusted.
Turn clockwise to increase the response stability
Setup of the overexcitation threshold.
AMP
That limiter permits to protect the generator in case of over excitation due to load
MIN MAX conditions that could cause the rotor damage. Even if correctly set, this function does not
substitute external systems protections, it is only a completing device.
Turn clockwise to increase the limitation intervention threshold
6. CONTROL BY MEANS OF EXTERNAL DEVICE
6.1. EXTERNAL POTENTIOMETER
An external potentiometer for fine setting of the voltage reference can be connected to the
terminals P and Q.
This allows to:
change the voltage set-point by means of remote control device;
-
set the generator voltage reference with accuracy higher than the one of the internal
-
regulator potentiometer VOLT.
External potentiometer specifications are the following:
Setting range
±5%
±10%
As soon as the external potentiometer is connected to P and Q, a change in the global voltage
reference of the regulation system will occur; the internal trimmer VOLT must be set again to the
rated generator voltage.
In detail: put the external potentiometer cursor in mid position, and after that, turn VOLT
counterclockwise until to reach approximately the desired generator voltage.
963857121_M
Potentiometer specifications
- 1 W minimum
- 1 W minimum
EN
Mark V M16FA655A Marelli Motori
24