Sincro HB4 - Control Of Voltage And Frequency; BL4-U AVR Settings

6.4.4 BL4-U AVR
TheAVR controls the generator voltage. TheAVR is
used to keep a constant voltage when the load and
machineparametersvary.
TheAVR requires a so-called sensing connection; a
powersupplyfromaspecificcircuit(AUX);anoutputto
theexciter(+/-).Incaseofunbalancedordistortedload,
voltageregulationaccuracycouldbereduced.
Afrequencycontrolprogressivelyreducesthegenerator
excitationwhenthedriveenginespeeddropsbelowa
pre-set,adjustablethresholdpreventingover-excitation
atlowoperatingspeedsandabatingtheloadengage
effectsontheengine.
TheBL4-UAVRhastwodip-switchesforthefrequency
setting.Setbothswitchesto“ON”for50Hzoperation.
Setbothswitchesto“off”for60Hzoperation.
The output voltage can be changed by adjusting
potentiometer“V”.Runthegeneratingsettoitsnominal
speedandturnuntil the required voltage is obtained.
If a small variation in speed causes a change in
voltage,thentheunderspeedprotectionshouldfirstbe
calibrated.
Thevoltagesensingjumpershouldbeconnected:
• toterminals“115”and“0”,ifconnectedtoavoltage
between100and130V
• toterminals“230”and“0”,ifconnectedtoavoltage
between185and245V.
• toterminals“400”and“0”,ifconnectedtoavoltage
between340and480V.
Stability adjustment: if on load voltage fluctuations
are experienced adjust potentiometer “ST”, which
modulatesthereactiontimeoftheregulatortoexternal
inputs, thereby eliminating any instability in the
alternator-loadsystem.
Setting of the under speed protection at 50 (60)
Hz:startuprotationofthegeneratingsetadjustingitto
obtainafrequencyof46(56)Hz.Turntrimmer“UF”until
thevoltagebeginstodrop.Restorenominalspeed.
Remote voltage adjustment :
1) with potentiometer: wire the potentiometer
(5kOhm, 3W) to the terminals “EXT POT”. Run the
generating set to its nominal speed and adjust the
externalpotentiometerandeventuallyalsothetrimmer
“V”toobtaintherequiredvoltage.
2) Connection with controller or cosf regulator:the
AVRregulatoracceptsvoltageanalogicinput(0-5VDC,
observe polarity shown in figure) for remote voltage
adjustment.Tosetthesystem,followthisprocedure:
- Decrease the voltage by turning the “V” trimmer
counter-clockwise;
-Applyhalfthecontrolvoltageatthe“EXTpot”terminals
(2,5VDC);
- Act on the “V” trimmer to bring the voltage to the
nominalvalue;
in this way, the external controller can increase or
decreasetheoutputvoltage.
The various generator parameters are
factory set before testing: so no further
adjustments on the machine should be
necessary; in the event that the covers
needto beremovedfortheadjustments
andliveelectricalcontactsareleftbare,it
isimportantthatthisoperationbecarried
out solely by qualied specialists in
electricalplantmaintenance.
WARNING!
Allchangesinconnectionmustbecarried
outsolelybyaqualiedspecialist.
WARNING!
If the voltage is set any higher than its
maximum limit the generator may be
damaged.
WARNING!
If the under speed is set at too low
a frequency, the generator may be
damaged.Ontheotherhand,toohigha
frequency can cause voltage drops with
highloads.
WARNING!
Voltage
increasing
Voltage
decreasing
Underfrequency
protection limit
increasing
Underfrequency
protection limit
decreasing
Stability
decreasing
Stability
increasing
Voltage V
StabilityST
UnderspeedprotectionUF
StatorExcitator
Sensing
BL4-U
Supply
Frequencydipswitch
Connection with controller,
Observe polarity:
ITALIANOENGLISHFRANÇAISDEUTSCHESPAÑOL
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