Parr Instrument A2110E - Manual (Page 11)

Motor Controller
w w w . p a r r i n s t . c o m 11
Adjustments To Speed Control Board
There are fi ve trimpots in the speed control module
that can be used to adjust the performance of the
motor. These are set at the factory for optimum
performance and should not be disturbed unless
customized settings are required to match a par-
ticular set of operating conditions. The instructions
below should be followed carefully if these controls
are to be readjusted.
The CL, current limiting/torque adjustment is set at
the factory to 1.5 times the motor rating. It is intend-
ed to protect both the module and the motor against
overloads and heavy surge currents during startup.
It can also serve as a torque limiting device by re-
ducing the maximum power output of the system.
The IR, compensation adjustment is used to im-
prove motor control under varying load conditions.
If the loads do not fl uctuate, this control can remain
at approximately one-fourth of full setting. But if the
motor speed drops more than 2% under load, this
adjustment should be increased. If it is set too high,
the motor speed will fl uctuate in a cyclical manner.
The MAX, maximum speed adjustment controls the
maximum speed of the motor. To increase the mo-
tor speed, turn the control knob on the front panel
to its maximum setting, then use the MAX trimpot
to raise the speed to the desired level. Care should
be taken to ensure the setting will not allow the mo-
tor to turn faster than its maximum rated speed.
The MIN, minimum speed adjustment can be used
to raise the minimum motor speed. To change this
setting, turn the control knob on the front panel to
its minimum setting, then adjust the MIN trimpot
to obtain the desired minimum speed, this adjust-
ment will also affect the maximum setting, making it
necessary to adjust both MAX and MIN trimpots to
obtain the desired spread.
The ACCEL, acceleration adjustment is normally set
to provide controlled acceleration from zero to full
speed in 2 seconds. It can be adjusted to higher or
lower acceleration times anywhere between 0.5 and
4 seconds, but changing this setting will affect the
MAX speed and IR compensation which will have to
be readjusted. If the acceleration time is reduced to
0.5 seconds (6 o’clock trimpot position), increase the
IR trimpot one quarter turn clockwise and decrease
the MAX trimpot one fi fth turn counterclockwise. If
the acceleration time is increased to the maximum
time of 4 seconds (full rotation), the IR trimpot must
be decreased and the MAX increased in the same
rotation amounts mentioned above.
Speed Control Board