KB Electronics KBPC-240D - Manual (Page 18)

15
2. Do not leave the motor in a locked condition for more than a few seconds since
armature damage may occur.
F. IR Compensation (IR) – The IR comp circuit is used to stabilize motor speed under
varying loads. (Note: If control is in Tach Feedback mode, the IR trimpot should be
set to minimum - ccw.) Readjust the IR trimpot as follows:
1. Run the motor at approximately 30-50% of rated speed under no load and measure
actual speed;
2. Load the motor to rated current. Rotate IR trimpot so that the loaded speed is the
same as the unloaded speed measured in 1.
Control is now compensated so that minimal speed change will occur over a wide range
of motor load. (Note: Too much IR Comp will cause unstable [oscillatory] operation.)
G. Timed Current Limit (TCL) – Jumper J5 must be in the "TCL" position, in order for Timed
Current Limit to be operational. This trimpot determines the approximate amount of time
the drive will stay in Current Limit before trip out. The trimpot has an adjustment range
of .5-15 seconds and is factory set for seven (7) seconds. The trimpot can be reset
according to the desired trip time. Rotating the trimpot clockwise increases the trip time.
This function provides motor overload protection. (See page 9, section II, E 1,
"Application Note," for TCL operation.)
H. Jog Speed (JOG) – This trimpot is operational only when the optional RUN-STOP-JOG
Switch is installed (KB P/N 9340). In the JOG position the JOG trimpot can be used to
set the JOG speed.
VIII. FUNCTION INDICATOR LAMPS.
The control contains three function LED Indicator Lamps that reflect its operational status.
A. Power On Indicator (ON) – This lamp will glow GREEN when the AC line is connected
to the control.
B. Stop Indicator (STOP) – This lamp will glow YELLOW when the control is placed in the
STOP mode with the Start/Stop Switch.
C. Overload Indicator (CL) – When the motor is loaded to the current limit setpoint (CL
setpoint is established by the setting of jumper J4 and the CL trimpot), this lamp will glow
RED. If the control is allowed to stay in CL and then trips out in Timed Current Limit, the
OL LED will remain lighted, until the control is restarted with the Start/Stop Switch. If the
OL LED remains lighted during control operation, a fault condition may exist. Possible
causes for this condition are as follows:
1. Motor is overloaded – Check motor amps with DC ammeter in series with armature.
(If motor is shunt type, field may be open or not receiving proper voltage.)
2. Motor may be defective – Check motor for shorts or grounds.
3. The CL may be set too low – Check position of jumper J4 and CL trimpot.
NOTE: In some applications, especially those requiring the motor to cycle on and
off or from one speed to another, the OL indicator may blink indicating a transient
overload. This may be a normal condition for the application.
IX. OPTIONAL ACCESSORIES.
A. RUN-STOP-JOG Switch (P/N 9340) – This switch provides a momentary jog speed that
can be used to "inch" a machine into position. It assembles easily to the control via quick
connect terminals. A rubber switch seal is included in order to maintain watertight
integrity.
B. Forward-Brake-Reverse Switch (P/N 9339) – This module provides a reversing function
along with dynamic braking. A special hesitation switch is used along with an Inhibit
function which minimizes arcing and plug-reversing. The installation is made simple with
the use of quick-connect terminals. Note: Signal Isolator (P/N 9431) cannot be
installed with Foward-Brake-Reverse Switch.