KB Electronics KBAC-48 User Manual
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13.1 Minimum Speed (MIN) – Sets the minimum speed of the motor.
The MIN Trimpot is factory set to 0% of frequency setting. For a
higher minimum speed setting, rotate the MIN Trimpot clockwise.
See Figure 30 on page 23.
13.2 Maximum Speed (MAX) – Sets the maximum speed of the
motor. The MAX Trimpot is factory set to 100% of frequency
setting. For a lower maximum speed setting, rotate the MAX
Trimpot counterclockwise. For a higher maximum speed
setting, rotate the MAX Trimpot clockwise. See Figure 31
on page 23.
13.3 Acceleration (ACCEL) – Sets the amount of time for the motor
to accelerate from zero speed to full speed. The ACCEL Trimpot
is factory set to 1.5 seconds. For a longer acceleration time,
rotate the ACCEL Trimpot clockwise. For more rapid acceleration,
rotate the ACCEL Trimpot counterclockwise. See Figure 32
on page 23.
Note: Rapid acceleration settings may cause the current limit
circuit to activate, which will extend the acceleration time.
13.4 Deceleration (DECEL) – Sets the amount of time for the motor
to decelerate from full speed to zero speed. The DECEL Trimpot
is factory set to 1.5 seconds. For longer deceleration time, rotate
the DECEL Trimpot clockwise. For more rapid deceleration, rotate the DECEL Trimpot
counterclockwise. See Figure 33.
Application Note – On applications with high inertial loads, the deceleration may automatically
increase in time. This will slow down the decrease speed to prevent the bus voltage from rising
to the Overvoltage Trip point. This function is called Regeneration Protection. It is recommended
that for very high inertial loads that both the ACCEL and DECEL Trimpots be set to greater
than 10 seconds.
13.5 DC Injection Brake (DECEL) – The drive is factory set for Regenerative Braking (Jumper J7 set to
the “RG” position). When the drive is set for DC Injection Brake (Jumper J7 set to the “INJ” position),
the DECEL trimpot is used to set the DC Injection Brake voltage and time. See Figure 34. Also see
Section 6.6 on page 19.
The DC Injection Brake voltage and time range is 10% of full drive output voltage for 3 seconds with
the trimpot fully clockwise and 25% of full drive output voltage for 1 second with the trimpot fully
counterclockwise. Models KBAC-24D, 27D, 29 are factory set for 49 Volts for 1.2 seconds and Models
KBAC-45, 48 are factory set for 98 Volts for 1.2 seconds.
Adjust the trimpot so that the load stops within the required time.
13.6 Slip Compensation (COMP) – Sets the amount of Volts/Hz to maintain set motor speed under
varying loads. The COMP Trimpot is factory set to 1.5 Volts/Hz, which provides excellent speed
regulation for most motors. To increase the slip compensation, rotate the COMP Trimpot clockwise.
To decrease the slip compensation, rotate the COMP Trimpot counterclockwise. See Figure 35.
The slip compensation may be adjusted as follows:
0.3
(Shown Factory Set to 1.5 Seconds)
DECEL
20
3
1.5
17
10
Figure 33 – Deceleration
Trimpot Range
(Shown Factory Set to 49 Volts for 1.2 Seconds)
57, 1.0
DECEL
23, 3.0
43, 1.5
49, 1.2
31, 2.5
40, 2.0
(Shown Factory Set to 98 Volts for 1.2 Seconds)
114, 1.0
DECEL
46, 3.0
86, 1.5
98, 1.2
62, 2.5
80, 2.0
Models KBAC-24D, 27D, 29
Models KBAC-45, 48
Figure 34 – DC Injection Brake Trimpot Range
COMP
(Shown Factory Set to 1.5 Volts/Hz)
0
0.8
3
2.3
1.5
Figure 35 – Slip Compensation
Trimpot Range
CL
(Shown Factory Set to 160% Full Load)
40
200
80
160
120
Figure 36 – Current Limit
Trimpot Range