ABB ACS 502 Series, Installation & Start-Up Manual, Page: 79 / 92

Chapter 6 – Fault Tracing
ACS 502 Installation & Start-up Manual 6-5
Figure 6-1 shows the troubleshooting procedure if the display is not activated
when power is applied.
Figure 6-2 Troubleshooting Procedure
OK
1 2
3 4
5
6
7 8
+24V
+8V
GND
X401
Display not activated at power-up.
Are the line voltages OK?
(U1-V1,U1-W1,V1-W1)
Yes
No
Fault in the line. Is the DC-link voltage OK?
(about 1,4 times input voltage)
Yes
No
Remove Power and check the fuses
on the Main Circuit Interface Card
SNAT 726x INT.
OK
Remove power,
check the line fuses.
OK
Check the charging resistor R14
and diode and associated wiring.
Check the flat cables between
SNAT 726x INT and the Control Unit.
Measure the +24 V and +8 V aux. voltages
on flat cable terminal X401. (See figure.)
Replace the Control Unit.
Replace the Main Circuit Interface Card.
Not OK
OK
Not OK
OK
Replace the
failed fuses.
Not OK
Replace the
Main Circuit
Interface Card.
Not OK
Correct the cabling.
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