Figure 3.5 – gate pulse detail – typical scr (abb), Figure 3.6 – gate pulse test waveform – Rockwell Automation 1560E SMC Flex Smart Motor Controller User Manual
Page 77
Commissioning Procedures
3-9
1560E-UM050B-EN-P - June 2013
7. The gate-driver board voltage may be checked by connecting a DC
voltmeter to TP2 (+) and TP1 (-) (See Figure 3.4). With the specified
power supply connected, the voltage should be 12 ± 2 VDC.
8. The actual gate pulse may be checked by connecting an oscilloscope
between TP7 and TP1 (See Figure 3.4). The pulse should appear as
shown in Figure 3.5.
Microseconds
Volts
-2
0
2
4
6
8
10
12
14
-2
0
2
4
6
8
Microseconds
Volts
-2
0
2
4
6
8
10
12
14
-2
0
2
4
6
8
-2
0
2
4
6
8
10
12
14
-2
0
2
4
6
8
Figure 3.5 – Gate Pulse Detail – Typical SCR (ABB)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Milliseconds
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Milliseconds
Figure 3.6 – Gate Pulse Test Waveform
9. If no pulse is observed, and the yellow LED is lit, check for a shorted
gate on the SCR by removing the green plug and connecting an
ohmmeter to the gate leads. If the LED is not lit, and the circuit voltage
is as specified in step 7 (above), pinch the tab on the fibre-optic
connector and carefully pull it straight out of the receiver. The end of
the connector should glow red to indicate the presence of a gate signal.
If it does not, remove the other end of the cable from the interface
board and check that the grey transmitter is emitting red light. If it is,
the fibre-optic cable must be replaced. If it isn’t, the interface board
should be replaced.