F30027 — Power unit: Precharging DC link time monitoring

F30027 — Power unit: Precharging DC link time monitoring — is raised when the power unit DC link was not able to be precharged within the expected time. The drive coasts and waits for OFF and fault acknowledgment. The fault value in r0949 records the state in which precharging stopped and which internal enable signals of the power unit were still missing, so reading it points to the cause.

• No line supply voltage is connected, or the line contactor/line side switch has not been closed.
• The line supply voltage is too low, or it is set incorrectly in p0210.
• The precharging resistors overheated because there were too many precharging operations per time unit.
• The precharging resistors overheated because the DC link capacitance is too high.
• The precharging resistors overheated because power is taken from the DC link although the infeed unit is not ready for operation (r0863.0) — described for configurations that feed other drives from the same DC link.
• The precharging resistors overheated because the line contactor was closed during the DC link fast discharge through the Braking Module.
• The DC link has a ground fault or a short-circuit.
• The precharging circuit is possibly defective — the infeed manuals restrict this to chassis units.
• The infeed is defective and/or a fuse has ruptured in the Motor Module (only Booksize units).

1. Check the line supply voltage at the input terminals and make sure the line contactor or line side switch is actually closed.
2. Check the line supply voltage setting in p0210 against the supply actually connected — on the G115D and G120C the manual names exactly this check for the fault.
3. If the unit has precharged repeatedly, let the precharging resistors cool down — approx. 8 minutes on booksize drive units, preferably disconnecting the infeed unit from the line supply — and afterwards carefully observe the permissible precharging frequency.
4. Check the total capacitance of the DC link and reduce it if it exceeds the maximum permissible DC link capacitance.
5. Where drives are connected to the same DC link, interconnect the ready for operation signal of the infeed unit (r0863.0) in their enable logic.
6. Check the connections of the external line contactor — it must be open during the DC link fast discharge through the Braking Module.
7. Check the DC link for ground faults or short circuits.
8. On chassis units the precharging circuit may be defective; on Booksize units compare the DC link voltage of the infeed and of the Motor Modules (r0070) — if no voltage is displayed at a Motor Module, its fuse has ruptured, otherwise the infeed may be defective.

• The drive displays Enable signals: %1, Status: %2: %1 is the missing internal enable signals, %2 the power unit state. Both come from the fault value in r0949, which is to be interpreted binary as yyyyxxxx hex.
• yyyy — power unit state (numbering as printed for G130/G150 and G120/G120XA):
  • 0 — fault status (wait for OFF and fault acknowledgment)
  • 1 — restart inhibit (wait for OFF)
  • 2 — overvoltage condition detected, change into the fault state
  • 3 — undervoltage condition detected, change into the fault state
  • 4 — waiting for the bridging contactor to open, change into the fault state
  • 5 — waiting for the bridging contactor to open, change into restart inhibit
  • 6 — commissioning
  • 7 — ready for precharging
  • 8 — precharging started, DC link voltage lower than the minimum switch-on voltage
  • 9 — precharging, DC link voltage end of precharging still not detected
  • 10 — waiting for the end of the de-bounce time of the main contactor after precharging
  • 11 — precharging completed, ready for pulse enable
  • 12 — it was detected that the STO terminal was energized at the power unit (reserved: G120/G120XA)
• On the chassis infeeds of S120/S150 an additional state 6 wait for bypass contactor to open shifts the following states up by one: commissioning is then state 7, precharging completed state 12 and the energized STO terminal state 13.
• xxxx — missing internal enable signals of the power unit, inverted bit-coded; FFFF hex means all internal enable signals are available:
  • Bit 0 — power supply of the IGBT gating shut down
  • Bit 1 — ground fault detected
  • Bit 2 — peak current intervention
  • Bit 3 — I2t exceeded
  • Bit 4 — thermal model overtemperature calculated
  • Bit 5 — (heat sink, gating module, power unit) overtemperature measured
  • Bit 6 — reserved
  • Bit 7 — overvoltage detected
  • Bit 8 — power unit has completed precharging, ready for pulse enable
  • Bit 9 — STO terminal missing (reserved: G120/G120XA)
  • Bit 10 — overcurrent detected
  • Bit 11 — armature short-circuit active (reserved: G120/G120XA)
  • Bit 12 — DRIVE-CLiQ fault active (reserved: G120/G120XA)
  • Bit 13 — Vce fault detected, transistor de-saturated due to overcurrent/short-circuit
  • Bit 14 — undervoltage detected

• p0210 — the line supply voltage set in the drive unit; set it to the voltage actually connected and verify it whenever this fault occurs.
• r0949 — fault value; read it binary as yyyyxxxx hex to see where precharging stopped and which internal enable signals were missing.
• r0070 — displays the DC link voltage; compare the infeed and Motor Module readings on Booksize units to find a ruptured Motor Module fuse.
• r0863.0 — the ready for operation signal of the infeed unit; interconnect it in the enable logic of drives that share the DC link.

After the cause is removed, switch the drive off and acknowledge the fault immediately at the operator panel or in the commissioning tool; until then the power unit stays in the fault state that r0949 reports as state 0, wait for OFF and fault acknowledgment. If the precharging resistors may have overheated, disconnect the infeed unit from the line supply and let them cool down before switching on again; the power unit then runs through precharging once more.