Exciter Stator - MarelliMotori M8B 315 Instrucciones Y Advertencias De Seguridad

Radio interference suppressor
The voltage regulator is internally provided with radio interference suppressor, in order to limit the radio interference from the
generators M8B to within levels stated by C.E. standards for industrial areas.
Fuse
On the AVR there is a protecting fuse. In case it should be necessary to replace it, high speed fuses should be used; in addition
they should have high breaking resistance with a rated voltage of 500V, and rated current of 10A.
Connection of AVR
The AVR is connected to the terminals of the generator and to exciter using FAST-ON terminals.
Use of potentiometers
STAB - potentiometer for stability adjust
⇒ decrease response time, decrease stability
FREQ - potentiometer for changing the low speed protection.
Usually it is set in order to reduce the excitation when the speed is 10 % below the rated value at 50 Hz. By removing the bridge
which is normally shorting terminals "60-Hz", the low speed protection acts properly for 60 Hz.
⇒ decrease frequency of intervention
VOLT - potentiometer for adjusting the output voltage of the generator.
It allows a wide range of voltage setting (i.e. between 350 and 470 V; or between 170 and 260 V depending on winding
connections)). In case of resetting this potentiometer the voltage has to be set within 5% of the rated voltage of the machine.
In order to obtain a finer regulation, or to adjust the voltage from control panel or to limit the voltage range, it is possible to
insert an external potentiometer
⇒ increase voltage
STAT - potentiometer for changing the droop
In order to obtain a correct sharing of reactive power, when two or more generators are required to operate in parallel, it is
necessary to verify that the no load voltage is the same, that the bridge between "A-B" is open and the voltage droop is the
same for all generators when loaded.
When this unit is inserted the output voltage should show a 4% voltage droop when passing from no load to full load 0.8 p.f.
If the voltage is increasing as the load increases, it is necessary to reverse the leads of the current transformer at the terminals
"A-B". If necessary, the voltage droop can be reset by acting on the internal potentiometer.
⇒ the droop increase
In single operation the terminals A and B have to be shorted.
STAB
FREQ
P/Q
60/Hz
A/B
6
8
M
VARICOMP
VOLT mini switch 1÷ 5
STAT
∼
- + 300
230 400
Voltage
reference
⇒ increase response time, increase stability
⇒ increase frequency of intervention
⇒ decrease voltage
⇒ the droop decrease
1 2 3 4 5
- + 0 U
Supply

Exciter Stator

16
ENGLISH
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