Parker 514C Product Manual page 33

and then remain steady. If necessary adjust P6 and P7 slowly to obtain a Critically Damped
performance, i.e., the fastest response possible without overshoot, as shown in Figure 3.
Figures 1 and 2 show typical armature current waveforms where P6 and P7 are incorrectly set
and indicate the adjustment required to improve the drive performance to conform to that of
Figure 3.
In general, clockwise rotation of the presets will improve the speed of response, but rotating
the controls too far will tend to introduce overshoot.
FIGURE 1.
ARMATURE CURRENT WAVEFORM:
Current Loop controls incorrectly set -
Integral Time Constant too short -
Increase Current Loop Integral Time
Constant by rotating P7 anti-clockwise.
5. When the Current Loop response adjustment is completed, switch off the drive and disconnect
all supplies.
Reconnect the field wires to terminals F+ and F- ensuring that they are replaced in their
original positions i.e., with correct polarity. Remove any mechanical devices previously used
to lock the motor shaft.
Speed Loop Adjustment (P3 and P4)
1. If the Speed Setpoint is applied via the setpoint ramp turn P1 and P2 fully clockwise
minimum ramp time. Set the Speed Setpoint to zero. Switch the Diagnostic Unit to position
16 so that the Oscilloscope displays the scaled Tacho Feedback signal ( 2.7v =  100%).
2. Reconnect the supplies switch on and
initiate "Run". Apply a small set
change (about 20%) to the Speed
Setpoint input and observe the speed
response. If necessary adjust the Speed
Proportional and Speed Integral presets
(P3 and P4) gradually to obtain a
Critically Damped performance, i.e.,
the fastest response possible without
overshoot, as shown in Figure 4, Curve
(c). In general, clockwise rotation of
the presets will improve the rate of
response, but advancing the controls
too far will tend to introduce overshoot.
The optimum setting of P3 and P4 will
be a compromise between the two
extremes shown in Curves (a) and (b),
Figure 4.
514C Product Manual
FIGURE 2.
ARMATURE CURRENT WAVEFORM:
Current Loop controls incorrectly set -
Proportional Gain too low – increase
Current Loop Proportional Gain by
Rotating P6 clockwise.
SPEED
FEEDBACK
(Diagnostic 16)
SPEED
SETPOINT
(Diagnostic 15)
FIGURE 4.
Setting up & Commissioning
FIGURE 3.
ARMATURE CURRENT WAVEFORM:
Current Loop Response (P6 and P7)
correctly adjusted.
X %
X %
TYPICAL SPEED RESPONSE CURVES
4-8
(a) Under Damped
(c) Critically Damped
(b) Over Damped
TIME
TIME