Delta VFD550CP43S-21 - Page 644

Chapter 14 Fault Codes and DescriptionsCP2000
14-41
ID* Display on LCD Keypad Fault Name Fault Descriptions
77
STO Loss 2 (STL2) STO2–SCM2 internal loop detection error
Action and Reset
Action level Hardware detection
Action time Immediately act
Fault treatment parameter N/A
Reset method Hardware failure, and cannot reset. Cycle the power.
Reset condition N/A
Record Yes
Cause Corrective Actions
STO2 and SCM2 short circuit lines
are not connected
Connect the short circuit lines
Hardware failure
After you make sure all the wiring is correct, if STL2 fault still exists after cycling
the power, please return to the factory for repair.
Poor connection of the IO card
Check if the PIN of IO card is broken?
Check if the IO card connects to the control board correctly, and if the screws
are tightened well?
The IO card does not match the
version of the control board
Contact local agent or Delta
ID* Display on LCD Keypad Fault Name Fault Descriptions
78
STO Loss 3 (STL3)
STO1–SCM1 and STO2–SCM2 internal loop detection
error
Action and Reset
Action level Hardware detection
Action time Immediately act
Fault treatment parameter N/A
Reset method Hardware failure, and cannot reset. Cycle the power.
Reset condition N/A
Record Yes
Cause Corrective Actions
STO1 and SCM1, or STO2 and
SCM2 short circuit lines are not
connected
Re-connect the short circuit lines
Hardware failure
After you make sure all the wiring is correct, if STL3 fault still exists after cycling
the power, please return to the factory for repair.
Poor connection of the IO card
Check if the PIN of IO card is broken?
Check if the IO card connects to the control board correctly, and if the screws
are tightened well?
The IO card does not match the
version of the control board
Contact local agent or Delta