24
Rockwell Automation Publication 20P-TG003B-EN-P - September 2021
Chapter 2
Component Test Procedures
4.
Verify that the value of parameter 280 [Nom Mtr Fld Amps] matches the
rated field current value on motor nameplate and make any necessary
corrections.
5.
Remove the protective covers from the drive. See
Removal and Installation on page 43
.
6.
Measure the field current signal on the green LA-LB terminal located on
the control board: LA is the ground and LB is field current signal. The
measured value of the field current at LA-LB should be equal to the value
of parameter 374 [Drv Fld Brdg Cur]. If these values are equivalent, the
voltage across these terminals should be 1.66 VDC.
Note: For lower field current values, the voltage will be proportional.
For example, if the field is set up for 2 A and the motor is rated for 1.5 A,
the measurement at LA-LB will be 1.245 VDC (1.5 / x = 2 / 1.66).
•
If the voltage measurement is incorrect, continue with step 7 below.
•
If the voltage measurement is correct, but the “Field Current Loss” fault
still exists, replace the control board.
7.
Using an ohmmeter, measure the resistance across terminals LA-LB to
verify that the value equals the equivalent resistance as indicated in the
table below (set with DIP switch S14 on the control board).
•
If the resistance measurement is incorrect, replace the field board.
Switch ohms:
168.5
333.3
182
36.4
845
1668
3333
–
Equivalent
Resistance
Field Current
Scale
Field
Supply
S14-1
S14-2
S14-3
S14-4
S14-5
S14-6
S14-7
S14-8
Ohms
1 A
10 A
OFF
OFF
OFF
OFF
OFF
ON
Not used
(OFF)
1668
2 A
OFF
OFF
OFF
OFF
ON
OFF
845
3 A
OFF
OFF
OFF
OFF
ON
ON
560.9
5 A
OFF
ON
OFF
OFF
OFF
OFF
333.3
10 A
ON
OFF
OFF
OFF
OFF
OFF
168.5
13 A
14 A
ON
OFF
OFF
OFF
ON
ON
129.6
17 A
20 A
OFF
ON
ON
OFF
ON
ON
97.3
20 A
ON
OFF
ON
OFF
OFF
ON
83.1
