Siemens Masterdrive P115-2 F002: Motor ID Fault Resolution

1. Problem Summary

A Siemens SIMOVERT Masterdrive (typically the 6SE70 / 6SE7090 / 6SE70VC series) returns fault F002 (precharge / precharging monitoring fault) the moment the technician initiates automatic motor identification with P115 = 2. The condition is reproducible: manual starting of the drive still runs the motor (the contactor pulls in, line is healthy, motor turns), but the moment the drive is asked to perform the identification routine the unit trips on F002. In nearly every documented case this is a symptom, not a hardware failure on the precharge resistors. The actual root cause sits in the parameter set the drive was never told to use, in motor nameplate data that has not been re-entered after a motor swap, or in the power-section definition that is still the factory default for a different kW rating.

2. Understanding P115: Function Stages

P115 is the Masterdrive parameterization controller. It has four meaningful states, and the order in which they are executed is critical when a motor has been replaced with a different brand or frame size.

When a motor is replaced, P115 = 1 must be run first. P115 = 1 reads P100–P109 (motor nameplate) and the power section data, then calculates every derived controller parameter (current loop P, speed loop P/I, field-weakening thresholds, torque limits, I²t model). The drive is stationary during this calculation. P115 = 2 is the rotating identification – the drive pulses the motor, measures stator resistance, leakage inductance, and rotor time constant. The DC bus must be solid, the output stage must be enabled, and the controller parameters calculated by P115 = 1 must already be in RAM, or the rotating routine cannot start its measurement sweeps.

3. What F002 Actually Means on a Masterdrive

Fault F002 belongs to the power-section fault group in the 6SE70 fault list. The internal name is "precharge fault" (German: Netz-Einschalt-Fehler). The drive monitors the DC-link voltage during the precharge window after the line contactor is commanded closed. The internal thresholds are roughly:

• Within 250 ms of the ON command: V_DC must rise above 80% of the rectified peak of the line-to-line voltage.
• After precharge: V_DC must remain above the undervoltage threshold (P361 area) for the entire identification run.
• If V_DC collapses or never reaches threshold, F002 is raised and the output stage is inhibited.

Two physical reasons and four parameter-related reasons can produce F002 during P115 = 2:

Because the original poster confirmed that the line contactor pulls in and the motor turns when running the machine manually, the physical line is healthy. That leaves the parameter path, which is the path that P115 = 1 was designed to expose.

4. Root Cause Analysis

The failure mode reported in the original incident fits a repeatable pattern. The drive had been put into service with a new motor brand, the technician entered only the rating values they could see on the nameplate (likely P101 voltage and P102 current), and then tried to start P115 = 2 directly. The Masterdrive does not infer the missing motor type, the missing cos-phi (P104), the missing frequency (P105), the cooling class (P108), and the pole pair number (P109) – and it does not infer the power section code. With those holes, the rotating identification cannot build the stator-flux model it needs to issue the first current pulse. The current controller tries to raise output voltage, the DC bus is momentarily loaded, the undervoltage monitor inside the precharge window flags the transient, and F002 is raised.

A second root cause is common after a motor swap: the technician never switched the drive to the parameter set the motor data was loaded into. The Masterdrive can hold four parameter sets in parallel (set 0 through set 3, plus a factory set 5 in some firmware). If P060 = 0 is left in place but the motor data was edited in set 1 or set 5, the drive is reading the empty factory values during P115 = 2 and the rotating routine aborts. The poster's own sequence of "take control from the drive and turn the drive on" confirms that the drive was never in the right parameter set to begin with.

5. Pre-Commissioning Prerequisites

Before P115 = 1 is even attempted, the following items must be on paper and in the drive. Skipping any one of them is enough to reproduce the F002 fault during P115 = 2.

1. Motor nameplate values – rated voltage (P101), rated current (P102), rated power (P103), cos-phi (P104), rated frequency (P105), rated speed (P106), efficiency if asynchronous (P107), cooling type (P108), pole pair number (P109). All nine must be present and dimensionally consistent.
2. Power section code – the alphanumeric code printed on the power stack label (for example "BD" for a 6SE7031-xEE60 or equivalent). This goes into P070 on most firmware. Refer to the Siemens Industry Online Support portal for the correct code for a given article number.
3. Line voltage – actual measured line-to-line RMS at the drive input terminals, not the nominal. Entered in P071.
4. Parameter set selection – P060 must be set to the set the data was written into. For a single-motor machine this is normally P060 = 0; for a machine with recipe selection it may be P060 = 1, 2, or 3.
5. Option board configuration – P050 through P055 must reflect the boards actually installed in slots A through G. The Masterdrive will not enable the inverter section until the slot table is consistent with the detected hardware.
6. Enable chain – ON/OFF1, OFF2, OFF3, ramp-up enable, and controller enable must all be present at the control word source. Check r551 area for the current control word bit mask.

6. Step-by-Step Recovery Procedure

Use the following sequence on the PMU. Allow each step to complete before moving to the next. P115 = 1 may take 10–60 seconds. P115 = 2 will rotate the motor – uncouple the load if the application permits, or accept that the rotating measurement will be made under load (less ideal but acceptable if the load is constant torque and < 30% of rated).

1. Place the drive in parameter-set 5 (or the set you intend to use):

   P060 = 5     (or 0 / 1 / 2 / 3 per machine design)
   P       (press P to confirm)

2. Enter the motor nameplate data into the active parameter set:

   P100 = 1                    ; 1 = induction motor (2 = synchronous)
   P101 = [nameplate V]        ; line-to-line RMS volts
   P102 = [nameplate A]        ; rated armature/line current
   P103 = [nameplate kW]       ; rated mechanical power
   P104 = [nameplate cos-phi]  ; power factor at rated point
   P105 = [nameplate Hz]       ; rated electrical frequency
   P106 = [nameplate rpm]      ; rated mechanical speed
   P107 = [nameplate eff]      ; efficiency, 0.xx
   P108 = [cooling type]       ; 0 = self, 1 = forced-air, 2 = water
   P109 = [pole pairs]         ; pole pairs, not poles
   P       (press P to confirm each)

3. Confirm the power section definition:

   P070 = [power section code from the nameplate label]
   P071 = [measured line voltage L-L]
   P072 = [line frequency, 50 or 60]
   P073 = [rated drive current from the stack label]
   P       (press P to confirm each)

4. Trigger automatic parameterization (P115 = 1):

   P115 = 1     ; static calculation only, no rotation
   P           ; press P on the PMU to start
   ; Wait for the PMU display to return to the operating state.
   ; P115 will reset to 0 automatically when finished.

5. Read the result and clear any sub-faults:

   r947         ; read fault code buffer
   r949         ; read fault value (gives the parameter index that failed, if any)
   ; If a fault is present, reset with the OFF/ON key sequence
   ; (or use the dedicated fault reset via the control word, bit 7).
   ; Re-run P115 = 1 until r947 = 0 and r949 = 0.

6. Trigger motor identification (P115 = 2):

   P115 = 2     ; rotating measurement
   P           ; press P on the PMU to start
   ; Drive will ramp the motor, apply test pulses, and stop.
   ; P115 returns to 0 on completion.

7. Verify the result – read r947/r949 again. A clean run returns fault = 0. The newly calculated motor equivalent-circuit parameters are now in the read-only mirror parameters (r150 area on most firmware) and the live parameters used by the controller have been written.

7. Reading the Fault Buffer (r947, r949)

The Masterdrive fault memory is a ring buffer. The parameters of interest are:

The r949 sub-status is the most useful field for separating the four parameter-related causes listed in section 3. The Siemens Masterdrive Compendium documents the full fault-value table in chapter 7 ("Faults and Alarms"). If the value stored in r949 points at a parameter number (Pxxx), that parameter is the one that prevented P115 from completing. Correct the parameter and re-run.

8. P060 Parameter Set Selection Deep Dive

P060 on the Masterdrive is multi-dimensional and the firmware behaviour depends on the build. In most cases:

• P060 = 0 – the operating parameter set (the live one used by the drive).
• P060 = 1, 2, 3 – alternative parameter sets for motor 2 / 3 / 4 selection (motor data switchover, e.g. star-delta or dual-motor machines).
• P060 = 5 – the factory / commissioning parameter set on most 6SE70 firmware. Setting P060 = 5 is the recommended starting point when commissioning a new motor because it gives a known clean baseline, and it is also the set P115 = 1 uses as its reference.

When a motor has been swapped, the typical mistake is to leave P060 = 0 (live set) and edit P100–P109 directly. The edits land in set 0, but if the drive has been power-cycled and re-initialised from set 5 (factory), those edits are no longer visible. Always set P060 to the set you want to read and write, confirm with the P key, and then proceed.

9. Motor Data Parameters (P100–P109)

The nine motor data parameters are the single largest source of "won't run P115" faults. The table below lists the realistic values and the formula constraints they must satisfy.

Single-phase current and three-phase current are the most common confusion when entering P102. A nameplate that shows line current of 360 A on a 400 V motor at 50 Hz with cos-phi 0.88 and efficiency 0.95 must be entered as 360 A. If the supplier quotes 360 A as per-phase, that is unusual for a line-frequency nameplate, but verify with the manufacturer before entering. The dimensional check above is the safety net: P101 × P102 × P104 / (1000 × √3) for three-phase should land within 10% of P103.

10. Power Section Definition

The power section code tells the Masterdrive which IGBT stack is actually bolted to the heatsink. Without the correct code, the current transducer scaling, the gate-drive timing, and the I²t model are all wrong. For 6SE70 the power section code is entered in P070 (older firmware) or P060 in a sub-index on newer firmware. The code itself is the alphanumeric string printed on the power stack label, e.g. "6SE7031-2EF60" for a 22 kW 400 V chassis. If the drive was ordered with a different power section than the one installed, F002 can also be raised because the firmware is trying to enable an inverter section the hardware cannot honour.

The board configuration parameters (P050–P055) assign the option boards to functional slots. A missing CB (communications board), T100/T300 (technology board), or SCB (serial communication board) configuration will not cause F002 directly, but it will prevent P115 = 1 from completing because the parameter set cannot be saved to a non-existent option slot. The SIMOVERT Masterdrive Compendium lists the slot-to-function mapping in chapter 6.

11. Verification and Commissioning Tests

After P115 = 2 returns clean and the drive is back at the operating display, run the following four verification checks. They take less than five minutes and they confirm that the parameter set is internally consistent.

1. No-load rotation check – issue a small setpoint (5% of rated speed), confirm smooth rotation, current draw within 10–25% of P102 (magnetising current).
2. Rated-point current check – bring the drive to rated speed, no load, and read the output current in r026 (or the relevant status word). It must be within 5% of P102. A 50% deviation means P104 (cos-phi) was entered wrong.
3. DC bus check – read the DC link voltage parameter (typically r017 or r018 depending on firmware). At 400 V line it must be approximately √2 × 400 ≈ 565 V DC. A value 20% low or high indicates the precharge path or P071 is wrong.
4. Fault buffer check – re-read r947 and r949. They must both read zero. Any non-zero value means the previous test triggered a fault that was not cleared.

If all four checks pass, the motor swap is complete and the drive is ready for production. Save the parameter set to the PMU using the parameter save sequence (typically P0525 = 1 or the "Copy PMU → Drive / Drive → PMU" menu on the PMU).

12. Field-Proven Pitfalls

• Not uncoupling the load before P115 = 2. The rotating identification applies torque pulses to the motor. With the load attached, the controller can saturate, the DC bus is briefly loaded, and F002 trips at the undervoltage threshold. Always uncouple the motor from the gearbox or chain for the first pass.
• Stopping P115 = 1 before completion. P115 = 1 looks like nothing is happening on the PMU – the display freezes for 10–60 seconds. Interrupting it by pressing P again or removing the ON command leaves the controller parameters in an undefined state. The next attempt to run P115 = 2 will fault.
• Using P115 = 2 without the enable chain. P115 is a self-contained routine, but it still requires the same ON command as normal operation. If the enable chain is wired through a safety relay that is held open during commissioning, P115 = 2 will fault within a few hundred milliseconds of trying to ramp the motor.
• Parameter set switchover mid-identification. Some machines use parameter set switchover through digital inputs (e.g. recipe select). If the input toggles while P115 = 2 is running, the drive jumps to a different parameter set mid-measurement and faults.
• Motor rated current higher than drive rated current. P115 = 1 will accept it, but the I²t model will trip the drive every time P115 = 2 tries to magnetise the motor at rated flux. Drop the flux setpoint (P157 = 0.7 for example) before identification, then restore it after.
• Assuming a second motor swap is identical to the first. Each motor brand has its own magnetising curve and rotor time constant. Always re-run the full P115 = 1 → P115 = 2 sequence after every motor change, even if the nameplate values are very close.
• Forgetting the power section code on a refurbished drive. If the drive was returned from a repair with a different power section than the label in the cabinet shows, P070 must be updated before any of P115 is attempted. A wrong P070 will give the same F002 because the current controller cannot build a stable model.

13. What If F002 Persists After a Correct P115 Run?

If the procedure above has been followed in full and F002 is still raised on the very first attempt to run the drive in production, the issue is no longer parameter-related. Switch to physical diagnostics:

1. De-energise and lock out the drive. Verify the line contactor pulls in mechanically and its auxiliary contact is wired to the digital input that releases the OFF2 interlock.
2. Measure each phase at the input terminals of the drive while the line is energised. The three values must be within 3% of each other. A blown line fuse shows as zero on one phase and a rising V_DC of about 300 V instead of 565 V – and F002 follows.
3. Measure the resistance between each output phase and the DC bus positive / negative with the drive isolated. A shorted IGBT module reads close to zero.
4. Inspect the precharge resistors. The chassis-type Masterdrives (6SE7031, 6SE7032, 6SE7033) use discrete wire-wound resistors on the input side. The cabinet-type units integrate them into the power block. A cracked or burnt resistor raises F002 within a few minutes of line energisation.
5. If all of the above are clean, the fault is in the VBC (Voltage Board Card) or the CUVC (Control Unit). Replace the CUVC first, then the VBC. The Siemens support portal has the spare-parts list for each power section code.

14. Long-Term Storage of the Parameter Set

After a successful P115 = 1 / P115 = 2 sequence, the parameter set must be saved non-volatilely. The Masterdrive stores parameters in the CU (control unit) and optionally on an EEPROM card. Use the PMU sequence:

• P0525 = 1 – copy PMU → drive (used when parameters were entered from a memory card).
• P0525 = 2 – copy drive → PMU (the recommended save path after P115).

The copy is mandatory. Without it, the next power cycle loads the factory set 5 again and the calibrated motor data is lost. A drive that has been parameterised with P115 = 1 and P115 = 2 but never saved will look like it has never been commissioned, and the next F002 will appear out of nowhere a week later when the cabinet is de-energised for a shutdown.

15. FAQ