Rapid-Air STRAIGHTENER / RAPID-ROLL: SA3 - SD with compact control - Manual (Page 19)

WARNING: if adjustments are made
under power, insulated adjustment
tools must be used and eye protection
must be worn.
The RAMM has been factory adjusted
to provide 0-full speed using the
speed control knob. Minimum and
Maximum speed trimpots are provid-
ed to change the speed from other
than 0-full speed. The Acceleration
(ACCeL) trimpot is provided to allow
for a smooth start over an adjustable
time period each time the AC power is
applied or the speed pot is rotated.
The DeCeL trimpot controls the amount
of ramp-down when the speed pot
is adjusted to a lower speed. The
Current Limit (CL, or torque output)
adjustment is factory set to approxi-
mately 1-1/2 times the motor rating.
The iR Compensation (iR) is factory
adjusted to provide excellent motor
regulation under normal operation.
NOTE: in order for the iR comp and
CL trimpot settings to be correct, the
proper Plug-in Horsepower Resistor
must be installed for the particular
motor and input voltage being used.
Do not attempt to change the settings
of the trimpots unless absolutely
necessary since they are factory
adjusted to near optimum settings.
The following procedure, presented in
order of adjustment sequence, should
be used when readjusting all trimpot
functions.
FIGURE 2: ACCEL/DECEL
Trimpot ADJUSTMENT
A. Acceleration Start. The ACCeL
is factory set at approximately
.2 seconds. To readjust to
different times, set the knob to the
desired position as indicated in Fig 2.
B. Deceleration. The DeCeL is
factory set to provide a ramp-
down time of .2 seconds. To
change the ramp-down time,
adjust the DeCeL trimpot as
indicated in Fig 2.
C. Minimum Speed Adjustment. if a
higher than zero minimum speed
is desired, readjust the minimum
speed by turning the speed control
knob to zero setting (full CCW
position). Then adjust the Min.
Speed trimpot to the desired setting.
NOTE: The min. speed adjustment
will affect the max. speed setting.
Therefore, it is necessary to readjust
the max. speed after the min. speed is
adjusted.
D. Maximum Speed Adjustment. Turn
Speed Control Knob to full speed
(maximum CW position). Adjust max.
speed trimpot to new desired setting.
NOTE: Do not attempt to adjust the
max. speed above the rated motor
RPM since unstable motor operation
may occur. For moderate changes in
the max. speed, there will be a slight
effect on the min. speed setting.
e. Current Limit (CL/Torque Adjust-
ment). CL circuitry is provided to
protect the motor and control
against overloads. The CL also limits
the inrush current to safe level
during startup. The CL is factory
set to approximately 1.5 times the
full load rating of the motor. (CL
trimpot is nominally set to ap-
proximately 65% of full CW rotation).
To set the CL to factory specifications
adjust as follows:
1. Set speed control knob at approxi-
mately 30-50% CW rotation. Set CL
trimpot to full CCW position.
2. Connect a DC ammeter in series
with the armature lead.
3. Lock shaft of motor (be sure CL
pot is in full CCW position).
Apply power and rotate CL pot CW
slowly until DC ammeter reads 1.5
times motor rating (do not exceed 2
times motor rating, Max. CW position.)
NOTE: if only an AC ammeter is avail-
able, it can be installed in series with
the AC line. Follow above instructions;
however, set AC amperage at .75
times motor rating.
F. IR Compensation Adjustment. iR
compensation is provided to sub-
stantially improve load regulation.
if the load presented to the motor
does not vary substantially, the
iR adjustment may be set at a
minimum level (approximately 1/4
of full setting). The control is
factory adjusted to approximately
3% regulation. if superior perfor-
mance is desired (less than 1%
speed change of base speed
from 0 to full load), then the iR
comp. Should be adjusted as follows:
NOTES: 1. excessive iR comp. will
cause control to become unstable,
which causes motor cogging.
2. For tach feedback applications the
iR comp can be set to minimum rota-
tion (full CCW).
1. Set iR comp. trimpot at approxi-
mately 25% of CW rotation. Run
motor unloaded at approximately
1/3 speed and record RPM.
2. Run motor with maximum load and
adjust iR comp. trimpot so that
the motor speed under load equals
the unloaded speed per step 1.
3. Remove load and recheck
unloaded RPM. if unloaded RPM
has shifted, repeat procedure for
more exact regulation.
The RAMM is now compensated to
provide minimal speed change under
large variations of applied load.
adjuStmentS and control functionS
RAMM Adjustments And Control Functions