Service 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.
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 engine, turn the
VOLT and STAB trim-
mers (using a mini phillips screwdriver) fully in a counter
clockwise (Minimum) direction until you feel them hit their
stops.
Turn the
AMP
and
HER1Z
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 adjust clockwise.
The voltage 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.
Turn 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.
~
...
....
VOLTAGE
REGULATOR
DIAGRAM
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 rotate the
AMP
adjustment clockwise until the
output voltage 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, the yellow
LED
will turn off
and the alternator voltage will rise to its normal value.
Should 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
that
the
jumper
strap
is
in
place on
the
regulator board between
the
two
60
Hertz
terminals.
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.
~
....
~WESTERBEICE
Engines
&
Generators
65