MarelliMotori MEC-20 Manuel Utilisateur page 30

10. REGULATOR SET-UP
NOTICE: THE REGULATOR SETUP DEPENDS ON THE WIRING DIAGRAM USED. IF IT IS
FORESEEN A TERMINAL BOX WIRING OTHER THAN THE ONE WITH WHICH THE
ALTERNATOR IS PROVIDED, IT IS NECESSARY TO CHECK THE REGULATOR WIRING
DIAGRAM, WHICH MUST COMPLY WITH THE WIRING DIAGRAMS ILLUSTRATED IN THE
"DRAWINGS" CHAPTER. MOREOVER, IT IS ALWAYS NECESSARY TO REPEAT THE
REGULATOR PRELIMINARY SETUP ACCORDING TO THE PROCEDURE INDICATED IN
CHAPTER 10.
Initial settings
1 With the generator shut down, initially position the regulator potentiometers as indicated in the following
figure:
VOLT
MIN MAX
MIN
where:
❖
MIN potentiometer turned completely counter clockwise:
❖
½ potentiometer about midway;
❖
MAX potentiometer turned completely clockwise.
NOTE: Whenever there is an external potentiometer connected to terminals P and Q, that potentiometer
must be set midway (½).
2 The dip switches must be initially positioned, with the generator off, in relation to the type of machine and
characteristics of the system.
❖
Block A: position the dip switches as indicated in the following figure:
in which it is assumed that the sensing is 1-phase (for 3-phase sensing, turn dip switch 1 to the ON
position, see Par. 8.3).
❖
Block B: select the position of the dip switches as indicated in Par. 8.3.
3 With the generator shut down, check that there are at least one and only one of the following conditions:
❖
purple jumper between terminals P and Q;
❖
terminals P and Q connected to an external potentiometer of suitable value (see Par. 9.5).
Voltage setting
4 Start the generator and bring it to nominal speed: the voltage at the output terminals of the generator
must be less than the generator's rated voltage.
5 Turn the VOLT potentiometer clockwise until the generator output voltage reaches a value equal to about
the rated voltage.
6 Using VFINE, fine calibrate the generator voltage so that it is equal to the rated voltage of the machine.
Turn VFINE clockwise to increase the voltage, counter clockwise to decrease it.
Setting the underfrequency limiter
7 Decrease the generator rotation speed to 90% of the nominal speed.
8 Turn the FREQ potentiometer clockwise until both of the following conditions occur:
❖
the red LED lights up;
❖
the generator voltage starts to decrease below the rated value of the machine.
9 Return the rotation speed to the nominal value of the machine and check that:
❖
the red LED goes out;
❖
the generator voltage is at the rated value.
963857154_U
VFINE START
MIN MAX MIN MAX
½ MIN
FREQ SLOPE AMP
MIN MAX MIN MAX MIN
MIN MIN MAX
BLOCK A
PAR STAB
MAX MIN MAX MIN MAX
MIN MAX
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