MANUAL# 5005-2040-000-F UPDATED: 6/1/2021
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G. Calibration of the Current Mode Drive (SMA5015 Series)
The Drive in this configuration receives an analog, bi-polar input command, which is proportional to
the required motor current (motor torque). The following potentiometers (pots) will be set during
calibration: (Note: RV7 is a single turn pot and RV1-RV6, RV8-RV10 are 20-turn pots.)
PROCEDURE:
1. Apply the main power and fan power.
Visually confirm an “O” on the display. Depending on the
configuration of the Inhibit, Reset and +/-Limits, it may be necessary to make appropriate
connections to those terminals before the Drive will be enabled and energize the motor.
2. Slowly turn the Loop Gain (RV7) pot CW. The Motor should be stopped or turning slowly. Set
the Balance (RV3) for 0V across TB1 MTR.+ to TB1 MTR.-.
3. Set the desired peak current limit by adjusting RV6 while measuring voltage at TP6. The ratio is
1V = 6A. Battery box does not have to be connected to the Drive.
4. If AUX. Gain is desired, monitor voltage across J1-1 (AUX. INPUT) to J1-2 (AUX. RETURN). If
SIG. Gain is desired, monitor voltage across J1-3 (SIG. INPUT) to J1-4 (SIG. COM.). To set the
desired signal to current ratio for AUX. Gain adjust the RV1 (differential signal) pot and for SIG.
Gain adjust the RV2 (single-ended signal) pot. Apply a step command of 3-4 volts. Observe
commanded motor (scale is 10A/V) and set the desired signal to current ratio. For example,
3A/V (max is 30A/10V).
5. If the motor is rotating in the wrong direction for a given input polarity, power down and reverse
the motor leads.
6. Calibration complete.
Pots
Name of Pot
Notes
RV1
Differential Gain,
AUX
Sets the input voltage to current ratio for differential signal
input.
RV2
Signal Gain,
SIG
Sets the input voltage to current ratio for single-ended signal
input.
RV3
Balance,
BAL
Used to null any offset in the system.
RV4
Tach. Gain,
TACH
Sets the DC tachometer gain.
RV5
Compensation,
COMP
Used in conjunction with Tach. Gain to set the system
bandwidth.
RV6
Current Limit,
I LIMIT
Sets the maximum motor current. Shipped set CW (max).
RV7
Loop Gain,
LOOP GAIN
Used to shut off uncalibrated Drives. When the loop gain is
fully CCW, no current is delivered to the motor.
