KB Electronics KBAC-29 (1P) - Manual (Page 24)

12.4 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 rate of speed of decrease 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.
12.5 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 18.
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.
12.6 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 compensa-
tion, 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:
1. Wire an AC RMS ammeter in series with one motor phase.
2. Run the motor and set the unloaded speed to approximately 50% (900 RPM on 4-pole
1500/1725 RPM motors).
3. Using a tachometer, record the unloaded speed.
4. Load the motor to the nameplate rated current (AC Amps).
5. Adjust the COMP Trimpot until the loaded RPM is equal to the unloaded RPM.
6. The motor is now compensated to provide constant speed under varying loads.
23
0.3
(Shown Factory Set to 1.5 Seconds)
DECEL
20
3
1.5
17
10
FIGURE 33 – DECELERATION
TRIMPOT RANGE
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
Models KBAC-24D, 27D, 29 Models KBAC-45, 48
(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