Eliminated from:
9400 HighLine Single Drive SW V7.0, sizes 8 to 10 only
Behaviour of the new version?
When the power supply is disconnected, an earth fault error message is no longer output (bits 0 to 25 of error number C0168 = 0x007b0011).
Description of the problem
The drive indicates an earth fault despite undervoltage and controller inhibit (bits 0 to 25 of error number C0168 = 0x007b0011).
When does the problem occur?
The problem can occur with large drives (rated output currents >= 145 A) after disconnection of the power supply. When disconnecting the mains input voltage, the internal supply for the current detection is interrupted as well. The control card detects the generated interference signals as virtual current peaks and derives an earth fault from this.
Which products are affected?
9400 HighLine Single Drive SW ≤ V5.1, sizes 8 to 10 only
Possible diagnostics?
After interruption of the mains supply (discharging of the DC bus = undervoltage), the controller indicates an earth fault (bits 0 to 25 of C00168 = 0x007b0011).
Short-term measures/recommendations?
Since the output stages are inhibited when a DC-bus undervoltage occurs, an earth fault can actually not occur.
With an appropriate addition in the function block interconnection of the 9400 HighLine, an earth fault can - under these circumstances - be reset automatically. Below you can find a suggestion for an addition to the function block interconnection.
L_DcDWordToDInt1: converts the number of the current fault from the numerical DWORD format into the numerical DINT format
L_DcBitShift1: removes the six most significant bits of the error code (error response, instance ID) from the 32-bit display area because they are not important for the error evaluation
User code C3001: contains the earth fault error number (8060945 = 0x007b0011)
L_DcBitShift2: removes the six most significant bits of the comparison value (error response, instance ID) from the 32-bit display area because they are not important for the error evaluation
L_TbCompare2: compares the current error number with the earth fault error number
L_TbTransition1: generates a 1 ms-pulse when an earth fault
(L_TbCompare2.bOut = FALSE => TRUE) occurs
L_TbAnd1: checks if the undervoltage status (system variable
DI_bUVDetected) has already been detected when the earth fault (
L_TbTransition.bOut = FALSE => TRUE) occurs. Only if this is the case, the described function restriction is given and an auto-trip reset may be activated
L_TbTransition2: prolongs the 1 ms-pulse to a 500 ms-pulse
L_TbDelay1: delays the rising edge of
L_TbTransition2.bOut by 100 ms because the auto-trip reset must not be activated earlier than 100 ms after occurrence of the alleged earth fault. The output
L_TbDelay1.bOut controls the system input
DI_bTripReset3.
Evaluation:
The error only occurs sporadically with devices as of device size 8 (rated output currents >= 145 A).
With an appropriate addition of function blocks in the signal flow, an auto-trip reset function can be implemented in the controller so that the controller will be immediately switched to ready for operation again when the function restriction occurs.
Published with Service Message No. 38/2009
