“The Right Control for Your Application.”
12095 NW 39 Street, Coral Springs, FL 33065-2516
KB Electronics, Inc.
Phone: 954-346-4900; Fax: 954-346-3377
(A40288) - Rev. E - 6/6/2005 - Z3562E00
Page 18 of 20
Figure 26
Slip Compensation Trimpot (COMP) Range
13.6 Boost (DEC/B): When the drive is set for 50 Hz Motor Operation (Jumper J1 installed in the "50Hz" position), the DEC/B Trimpot
automatically becomes the adjustable BOOST Trimpot.
Most 60 Hz motors conforming to NEMA standards can operate from a preset Volts/Hz curve. 50 Hz motors, however, generally
differ widely in their characteristics. Therefore, it is necessary to have adjustable Boost to obtain maximum motor performance.
To increase the boost, rotate the BOOST Trimpot clockwise. To decrease the boost, rotate the BOOST Trimpot counterclockwise.
See
Figure 27, on page XX
.
In order for the 50 Hz motor to run properly, the boost must be adjusted. If the application does not require full torque below 10 Hz,
the Boost (DEC/B) Trimpot can be conservatively set at 8% (9 o'clock position).
Note: In 50 Hz motor operation, the deceleration time is automatically set to the same as the Acceleration Trimpot (ACC) setting.
WARNING! To avoid motor winding heating and failure, do not overboost the motor.
The Boost (DEC/B)Trimpot may be adjusted as follows:
1.
Wire an AC analog RMS ammeter in series with one motor phase. (Generally, digital or clamp-on meters do not provide
accurate readings.)
2.
Run the motor unloaded at approximately 4 Hz (or 120 RPM).
Note: An unloaded motor with excessive boost will draw more current than a partially loaded motor.
3.
Increase the boost until the ammeter reaches the nameplate rated current (AC Amps).
4.
Using the Main Speed Potentiometer, slowly adjust the motor speed over a 0-15 Hz (0-450 RPM) range. If the motor current
exceeds the nameplate rating, decrease the boost setting.
Figure 27
Boost Trimpot (DEC/B) Range
13.7 Motor Overload (I
2
t) with RMS Current Limit (CL)*: Sets the current limit (overload), which limits the maximum current to the
motor, prevents motor burnout, and eliminates nuisance trips. The CL Trimpot is factory set to 160% of the drive rating. To
increase the current limit, rotate the CL Trimpot clockwise. To decrease the current limit, rotate the CL Trimpot counterclockwise.
See
Figures 28 - 32, on pages XX - XX
.
* UL approved as an electronic overload protector for motors.
In order to ensure that the motor is properly protected with the I
2
t feature, it is required that the CL Trimpot be set for 160%
of the motor nameplate rating. This is accomplished as follows:
Note: This adjustment must be made within 6 seconds or the I
2
t Trip will occur.
1.
Connect an AC ammeter in series with one motor phase.
2.
Set the CL Trimpot fully counterclockwise.
3.
Adjust the speed setting to 30% of full speed.
4. Lock the motor shaft and adjust the CL Trimpot to 160% of the motor nameplate rating.
Example: A ½ HP motor has a full load current rating of 1.8 Amps. Set the CL Trimpot to 1.8 X 160% = 2.9 Amps.
