Rheostat For Remote Voltage Setting; Instructions For Manual Control Of Generators - MarelliGenerators MJB 160 Instructions Et Avertissements Pour L'installateur

5.2. Rheostat for remote voltage setting

For all generators, that rheostat can be inserted between the auxiliary terminals P and Q (FAST-ON terminals). The external rheostat
has to be inserted with its wiper in intermediate position and then the internal potentiometer of AVR (P1) has to be reset to obtain about
the nominal voltage. Rheostat features must be minimum rating 0.5W, resistance about 100 Kohm.

5.3. Instructions for manual control of generators

If the voltage regulator (AVR) breaks down, a manual control system can be used, when a 24 V D.C. power supply is
available.
This source could consist of a bank of batteries or of a voltage transformer and a rectifier unit connected at the alternator output.
- disconnect the two exciter stator terminals ( whites wire + and -) from AVR;
- apply the D.C. power supply to these two wires;
- set the rheostat R to adjust the alternator output voltage.
ATTENTION! Compensate by manually increasing excitation as the load increases.
Before removing the load, reduce the excitation current.
Use the following table to select the rheostat:
MJB 160 – 200 – 225
WHITE
EXCITER
STATOR
WINDING
TERMINALS
WHITE
Generator
24 V
R
I max
[A]
5
21
ENGLISH
Max. resistance of rheostat
[Ω]
80