B&C Technologies SA Series Industrial - Manual (Page 69)

TROUBLE SHOOTING
7-9
If an alarm code appears pm the LED monitor
1. “OCn” Overcurrent protection
Problem The inverter output current momentarily exceeded the over current level.
OC1 Overcurrent occurred during acceleration.
OC2 Overcurrent occurred during deceleration.
OC3 Overcurrent occurred when running at a constant speed.
Possible Causes What to Check and Suggested Measures
1. The inverter output
terminals were short
circuited.
Remove the wires connected to the inverter output terminals (U, V,
and W) and measure the inter phase resistance. Check if the
resistance is too low.
→ Remove the part that short – circuited (including replacement
of the wires, relay terminals and motor).
2. Ground faults occurred at
the inverter output
terminals.
Remove the wires connected to the inverter output terminals (U, V,
and W) and perform a Megger test.
→ Remove the part that short – circuited (including replacement
of the wires, relay terminals and motor).
3. Loads were too heavy.
Measure the motor current with a measuring device, and to trace
the current trend. Therefore, use this information to judge if the
trend is over the calculated load value for your system design.
→ If the load is too heavy, decrease it or raise the inverter
capacity.
Trace the current trend and check if there are any sudden changes
in the current.
→ If there are any sudden changes, make the load variation
smaller or raise the inverter capacity.
→ Enable current limiting (H12)
4. The value set for torque
boost (F09) was too large.
F37 = 0, 1, 3, or 4)
Check that the output current decreases and that the motor does not
come to stall if you set a lower value than the current one for F09.
→ Lower the value for torque boost (F09) if the motor is not
going to stall.
5. The acceleration /
deceleration time was too
short.
Check that the motor generates enough torque required during
acceleration / deceleration. That torque is calculated from the
moment of inertia for the load and the acceleration / deceleration
time.
→ Increase the acceleration / deceleration time (F07, F08, E10,
E11, and H54).
→ Enable current limiting (F43).
→ Raise the inverter capacity.
6. Malfunction caused by
noise.
Check if noise control measures are appropriate (e.g., correct
grounding and routing of control and main circuit wires).
→ Implement noise control measures.
→ Enable the auto – reset function (H04).