MarelliMotori M40FA610A MGC I Manuel Utilisateur page 13

5.3. Dip-switches
Dip-switch 1 – Stability setup
ON:
OFF: -
Dip-switch 2 – Stability setup
ON:
OFF: -
Dip-switch 3 – Underfrequency limiter setup
ON:
OFF: Proportional low speed protection - V/f
Dip-switch 4 and 5 – Disabled
ON:
OFF: -
6. UNDERFREQUENCY LIMITER
The regulator is provided with internal circuits in order to reduce the excitation, when running at low speed, in order to avoid
damages to the excitation system of the generator (i.e. to the regulator, to the exciter field, to the rotating rectifier, main rotor).
The potentiometer FREQ fixes the corner-frequency, that is the frequency at which the limiter operates.
7. STABILITY ADJUSTMENT
The voltage regulator is provided with internal adjustable stability circuits in order to allow stable operation in a wide range of
applications. The stability of the regulator can be set on field to adapt it to the characteristics of the plant and/or the driving
engine (diesel engine, water turbine, gas turbine) in order to obtain the best voltage response.
To change the stability characteristics of the regulator, it is necessary to act on the potentiometer STAB (for fine setting of
stability). An additional coarse setting of stability can be achieved by means of the micro-switches number 1 e 2.
8. KIT DEVICE
The device is included in the voltage regulator, to allow parallel operation between similar generators: the device permits to
share correctly the total reactive power required by the load among all generators operating in parallel. The device is composed
by an external current transformer (which senses the current in phase W) and the internal droop circuit of the regulator. The
voltage regulator is provided with input terminals (terminals A and B) for easy connection to an external current transformer.
Such terminals are normally shorted by a connection bridge, when the generator is used in single operation. 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.
Increase the time response
Increase the time response
Standard low speed protection
-
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