Voltage Regulator Adjustments - Westerbeke BTG 8.5 Operator's Manual

VOLTAGE REGULATOR ADJUSTMENTS
Description
The voltage regulator is an advanced design which ensures
optimum AC alternator performance. It
is
equipped with
complete protection circuitry to guard against operating
conditions that could be detrimental to the AC alternator.
Volts
This
potentiometer
is
used to adjust output voltage. At proper
· engine operating speed the output voltage should be held at
±1% from a no-load condition to a full rated generator output
·and from power factor 1.0 - 0.8 with engine drive speed vari-
ations up to
-6%.
Prior to starting the engini, turn the VOLT and STAB trim-
mers (using a
mini
phillips screwdriver) fully in a coun,ter
clockwise (Minimum) direction until you feel them hit'their
stops.
Thrn the AMP and HERTZ trimmers completely clockwise
(Maximum) in the same manner.
With the alternator running at no-load, at normal speed, and
with VOLT adjust at minimum, it is possible that output volt-
age
will oscillate. Slowly rotate the VOLT adju8t clockwise.
The vpltage output of the alternator
will
increase
and
stabi-
lize.
Increase the voltage to the desired value. In this situa-
tion, only the green LED will stay lit
Stability
This
potentiometer permits variation· of the regulator's
response to generator load changes so as to limit overcom-
pensation and obtain a minimum recovery time to the normal
voltage output ·
In order to adjust the regulator stability the alternator must be
·running at no-load and the output must be monitored.
Thrn the STAB adjuSt slowly clockwise until-the voltage
starts to fluctuate. At this point rotate the STAB adjust coun-
terclockwise until the voltage
is
stable within 1 or 2 tenths of
a volt.
Amp·Hertz
These two adjustments are used in conjunction with the two
protection circuits in the voltage regulator that are indicated
by the illumination of a colored LED lights.
1.
Delay~
overload protection (yellow LED).
2. Low speed protection (red LED).
Both systems have an intervention threshold which can be
adjusted using the respective potentiometer. Each of the two
circuits are able to cause an adequate reduction in excitor
voltage to safeguard the excitor windings and prevent their
overheating.
The overload protection system
has
a delay which permits
temporary overloading of the generator during times such as .
motor start-up or other similar load surge demands. The regu-
lator also
has
a
third
LED (green), that glows during genera-
tor operation to indicate correct operation of the regulator
with the generator.
Setting the Overload Protection
In order to set the AMP overload protection, the alternatOr
must be loaded to its full output rating. ·
1.
Load
the
alternator to its rating, then decrease the speed of
the engine by 10.10% (54 Hertz on 60 hertz units, 45
hertz on 50 hertz units).
2. Rotate the
AMP
adjustment counterclockwise until it hits
its stop. Wait about 15-20 seconds after which the AC out-
put of the alternator should drop and the yellow LED light
should come on. ·
3. Slowly
·rntate
the AMP adjustment clockwise until the
output
~ltage
increases to approximately 97% of the volt-
age output at the start of the adjustment. At this point the
yellow LED
light
should come on..
.4. Return to nominal speed,
th~ yellow LED will turn off ·
and the alternator voltage will rise to its normal value.
Sqol.ild this not happen, repeat the adjustment.
NOTE:
When changing from 60 hertz to 50 hertz operation,
remove the 60 hertz jumper bar from the regulator board.
Setting the Underspeed Protection
NOTE:
If
the
unit is operating
at
60 Hertz ensure
tluJt the
jumper strap
is
in place on the regulator board between the
two 60 Hertz tenninals. In order to adjust the underspeed
setting, the alternator should be running
at
no-load.
1. To adjust the underspeed (low frequency) protection circuit,
· lower the engine speed
at
90% of its normal running speed-
(54 hertz on 60 hertz units, 45 hertz on 50 hertz units.
2. Rotate the Hertz adjustment counterclockwise slowly until
the alternator's AC output voltage starts to decrease and at
the same time the
red
"LED"
light
comes on.
3. Increase the engine speed to its normal speed (frequency).
The red ''LED" light will go out and the AC voltage
out~
put will return to normal.
With
the above adjustments made, the regulator should func-
tion normally.
VOLTAGE REGULATOR DIAGRAM
I.,.,.,IWESI'ERBEICE
-. (Engines
&
c;lenerators
40