CUMMINS QST30 - Overcurrent Warning (320) or Shutdown; Short Circuit Shutdown; Overload Warning

4-42
Copyright  2017 Cummins Inc.
TABLE 4-29. OVERCURRENT WARNING (320) OR SHUTDOWN (321),
SHORT CIRCUIT SHUTDOWN (322), OR OVERLOAD WARNING (330)
WARNING
Many troubleshooting procedures present hazards that can result in severe personal inju-
ry or death. Only qualified service personnel with knowledge of fuels, electricity, and machinery haz-
ards should perform service procedures. Review Important Safety Instructions page.
Indicator(s) Possible Cause Corrective Action
“OVER-
CURRENT”
warning (320)
or shutdown
(321),
or
“SHORT
CIRCUIT”
shutdown
(322), or
OVERLOAD
warning (330)
message.
1. Short or Overload.
2. Incorrect CTs or CT connections.
3. The problem may be a bad PT/CT
module (A36).
4. The problem may be the customer in-
terface board (A34) or connections.
5. The problem may be the analog board
(A33) or the digital board (A32).
1. Check the load and load cables. Repair if nec-
essary.
2. Check CTs and CT connections. Correct if nec-
essary. Refer to Current Transfer Installation in
Section 5.
3. Disconnect the PT/CT module and check the
3-ohm resistors (J8-15 to 14, J8-22 to 23,
J8-7 to 8). Replace the module if necessary.
*4. Check continuity from A36—through A34—to
A33. Repair the connection or replace A34 if
necessary. Refer to Section 7 for pin reference.
5. Isolate, using the analog input troubleshooting
procedure (Table 4-30a/b). Check the bad
phase or phases.
*CAUTION: Wearing a wrist strap, set S12 to Off and A32 S5 to Standby before connecting/disconnecting harness plugs.