Simodrive 611 E/R Replacement: 6SN1145-1BB00-0EA1 to -0FA1

1. Overview

The Simodrive 611 power section family from Siemens uses modular E/R (Einspeise-/Rückspeise-Einheit) infeed and regenerative feedback modules to condition the three-phase mains supply and buffer the DC link voltage for downstream 6SN1123 (servo axis) and 6SN1124 (spindle) power modules. When an 80 kW class E/R module fails in the field and an exact replacement is not available on the spare shelf, the next-tier 120 kW unit (6SN1145-1BB00-0FA1) is electrically and mechanically compatible as a temporary substitute on a 611D drive line-up driven by a SINUMERIK 840D NCU. The two modules share the same 150 mm mounting footprint, the same 600 V DC bus interface (P600 / M600), the same X151 / X152 control interface, and the same T48 "DC link ready" enable logic. The differences between the two are confined to higher continuous current ratings, a larger internal cooling fan, and a requirement for an external 440 V AC auxiliary feed to drive that fan.

This article documents the field-proven replacement procedure used on a Simodrive 611D cabinet under SINUMERIK 840D control. It covers the mechanical swap, the auxiliary 440 V wiring, the 840D machine data adjustment (MD1237), the drive configuration reload, and the verification sequence that confirms safe operation before returning the machine to production. The procedure is appropriate for an emergency production-restoration scenario where the original 80 kW spare is unavailable, and the existing axis and spindle loading is well below 120 kW of nameplate capacity.

2. Prerequisites

Before commencing the swap, verify the following items are present and in date:

• Spare module on hand. 6SN1145-1BB00-0FA1 in known-good condition, with a clear rating plate. Confirm the variant suffix is exactly -0FA1 (not -0EA2 or any other variant); the suffix is the last two characters of the part number printed on the rating plate.
• Family confirmation. Both part numbers must be Simodrive 611D E/R (infeed/regenerative) modules. Verify on the existing unit's rating plate: the family code "E/R" or "Einspeise-Rückspeise" is printed, and the article number matches the expected 6SN1145-1BBxx-xxxx format. Do not confuse with I/R (intelligent regenerative), UE, or HFD variants.
• 440 V AC auxiliary feed source. A single-phase 440 V AC (or 400 V phase-to-phase from the main) supply available in the cabinet for the auxiliary fan feed. The 120 kW module requires approximately 0.3 A continuous at this terminal.
• SINUMERIK 840D access. HMI Advanced or HMI Embedded with the operator password, or a PCU50 / PCU70 with the original commissioning archive. You will need access to modify machine data MD1237 and to load drive configuration files.
• Upstream switchgear ratings recorded. Document the existing main fuse, contactor, line reactor, and line filter ratings. The 120 kW module draws the same current as the 80 kW module at the actual load, so the existing fuses and contactor may already be over-rated. The line reactor and RFI filter must be re-sized for a long-term installation — see Section 11.
• Tools. Torque wrench (Nm scale, 5–20 Nm range), M5 / M6 hex drivers, cable lugs sized for 35–95 mm² conductors, a Siemens SimoCom U commissioning lead or SIMODRIVE 611 Toolbox lead for parameter download, a Cat III 1000 V digital multimeter, and a 500 V insulation tester (megger) for pre-energization verification.
• Lockout / tagout provisions. Local LOTO kit, padlocks, and tags for the main cabinet disconnect, the 440 V auxiliary feed breaker, and the DC bus earthing point.

3. Module Identification and Ratings

Both modules belong to the Simodrive 611D E/R family. Confirm the exact ratings against the rating plate and the Siemens SIMODRIVE 611 digital Configuring Manual before commencing work.

Platform compatibility note. The 6SN1145-1BB00-0FA1 is a legacy SIMODRIVE 611D platform module and is for use with SINUMERIK 840D (and earlier 840C) NCUs only. It is not compatible with the SINAMICS S120 platform, which uses a different infeed module family (Smart Line Module, Active Line Module, Basic Line Module) with different part numbers, terminal assignments, and machine data. Do not attempt to use a SIMODRIVE 611 E/R module on a SINAMICS S120 drive line-up.

4. Safety and Lockout

1. Open the main cabinet disconnect and apply lockout / tagout (LOTO) per local site procedure. Lock the main breaker in the open position with a personal padlock.
2. Wait a minimum of five minutes for the DC link capacitors to self-discharge to below 60 V. Verify with a Cat III 1000 V meter across the DC bus bars: connect the positive (red) lead to P600 and the negative (black) lead to M600. Confirm the reading is below 60 V before continuing.
3. Confirm the SINUMERIK 840D HMI shows "Drive system not ready" or that the drive enable (terminals 663 / 65 in the 611D bus) is de-asserted.
4. Isolate the 440 V AC auxiliary feed breaker that will supply the new E/R fan. LOTO this breaker separately.
5. Apply a temporary ground stick to the DC bus bars to dissipate any residual charge. Remove before energizing.
6. Verify absence of voltage on the three-phase line input (U1, V1, W1) and on the auxiliary 440 V terminals (L1, L2) with a known-good voltage tester.

5. Pre-Swap Documentation

Capture the existing state of the drive before disturbing it. This documentation is essential if a rollback to the failed 80 kW unit becomes necessary and for the as-built record.

1. Photograph the existing E/R module from the front, showing the rating plate, all wired terminals, and the bus bar connections. Save with a timestamp.
2. Use the SINUMERIK 840D HMI to create a commissioning archive: Start-up → Commissioning → Create commissioning archive → Series start-up. Save to a USB stick or to the network share.
3. Note the existing MD1237 value: navigate to Start-up → Machine data → Drive configuration → MD1237 and write down the current integer value. This is the original 80 kW power section code.
4. From the 840D HMI Diagnostics → Drive system → Service display, capture the current DC link voltage, the heatsink temperature of the existing E/R, and the drive enable state. These are useful baselines for comparison after the swap.
5. Using SimoCom U or the SIMODRIVE 611 Toolbox connected to the 611D bus, download the drive parameter set (parameter P-Group 0–99) to a backup file. This file is recoverable to the new module after the swap.
6. Mark the three-phase line cables (U1, V1, W1), the T48 wire, the X151 / X152 control cables, the PE conductor, and the auxiliary fan feed conductors with numbered cable markers before disconnecting. Masking-tape tags with a felt-tip marker are adequate; thermal-printed wire markers are better.

6. Hardware Removal of the Failed 6SN1145-1BB00-0EA1

1. Open the Simodrive 611 cabinet door and locate the E/R module by the green "E/R" label on the front panel or by following the 6SN1145 rating plate. The E/R is always the leftmost (line-side) module in the 611D bus string.
2. Disconnect the marked cables in reverse connection order:
   • Three-phase power cables from terminals U1, V1, W1 (line input)
   • Auxiliary fan feed conductors (if any) from the internal terminals
   • T48 control wire from the DC link enable chain
   • Drive bus cables from connectors X151 and X152
   • PE (protective earth) conductor
3. Loosen the four M6 fixing screws on the module face (two at the top, two at the bottom). The unit is heavy — approximately 50 kg for the 80 kW class — and requires a second person or a lifting sling to remove safely. Do not lift the module by the bus bars or by the front handle alone.
4. Slide the module forward off the DC bus bars (P600 / M600). The unit has captive guides; do not pry. If the module does not slide freely, verify that all four fixing screws are fully retracted.
5. Inspect the bus bar contact surfaces once the module is removed. Light oxidation is acceptable and can be cleaned with a non-abrasive contact cleaner. Pitting, arc damage, or thermal discoloration requires refurbishment by a Siemens service center — the cabinet cannot be energized with damaged bus bars.
6. Place the failed module on a flat, insulated surface. If the unit is to be returned to a repair vendor, package in the original Siemens shipping carton with anti-static foam.

7. Hardware Installation of the 6SN1145-1BB00-0FA1

1. Confirm the replacement module is a -0FA1 variant. The rating plate must show "6SN1145-1BB00-0FA1". A -0EA2, -0FA2, or -0GA1 has different terminal assignments and is not a drop-in substitute.
2. Inspect the replacement module: no transit damage, no oil contamination on the bus bar surfaces, fan blades free and not cracked, all captive screws present.
3. Clean the new module's bus bar contact surfaces with a lint-free wipe and isopropyl alcohol. Allow to dry before mounting.
4. Mount the unit on the cabinet backplane. The mounting footprint matches the 80 kW unit exactly. Slide the module onto the DC bus bars (P600, M600) and tighten the four M6 fixing screws to the rated torque (typically 8 Nm — confirm in the equipment manual).
5. Reconnect the three-phase power cables to U1, V1, W1. Verify the conductor cross-section against the 120 kW module's nameplate rating. For a 120 kW continuous load at 400 V three-phase, the recommended minimum is 70 mm² copper with a 250 A gG fuse. The existing 35 mm² cabling from the 80 kW unit is undersized for the module's nameplate, but is adequate for the actual load because the connected motors have not changed.

   Use the standard three-phase apparent power formula to verify the existing cabling against the actual load:

   kVAload = √3 × VLL × Iline / 1000

   For an 80 kW load at 400 V: I = 80,000 / (√3 × 400) ≈ 115 A. A 35 mm² XLPE cable is rated approximately 131 A in free air, so the existing cabling is adequate for the actual load. For a permanent installation at the 120 kW nameplate, the cabling must be increased to 70 mm² or 95 mm² per local electrical code.

6. Reconnect the PE conductor to the module's grounding stud. Tighten to the rated torque.
7. Reconnect the T48 enable wire and the X151 / X152 drive bus cables to their marked positions.

8. Auxiliary 440 V AC Supply for the 120 kW Fan

The 6SN1145-1BB00-0FA1 is internally wired to accept a 440 V AC two-phase auxiliary supply on terminals L1 and L2 located on the underside of the module. On the 80 kW unit these terminals are not energized for the fan; on the 120 kW unit they must be supplied from an external 440 V source. Field experience confirms that wiring this feed is the single most common point of failure on a like-for-like upscale — if the fan does not run, the E/R trips on heatsink overtemperature within minutes.

1. Source the 440 V AC from one of the following:
   • A dedicated 440 V control transformer tap (preferred for new installations)
   • Phase-to-phase of the existing 400 V main (acceptable; the fan motor tolerates 380–440 V ±10%)
   • A separate 440 V supply from the cabinet's auxiliary distribution
2. Route 1.5 mm² (or 2.5 mm² for mechanical robustness) two-core cable from the source to terminals L1 and L2 on the underside of the new module. Polarity is not significant; the input drives a single-phase asynchronous fan motor.
3. Protect the auxiliary feed with a 2 A miniature circuit breaker (MCB) or a 2 A gG fuse in the cabinet's auxiliary distribution section. Label the breaker "E/R fan, 440 V" on the cabinet legend.
4. Update the cabinet schematic (electrical drawing) to reflect the new 440 V feed. The original -0EA1 wiring diagram does not show this feed; the cabinet documentation must be amended and re-issued per the site's documentation control procedure.
5. With the main disconnect still open, apply the 440 V AC auxiliary feed alone. Verify the internal fan runs and that the rotation direction matches the arrow on the module's front panel. Reverse the L1 / L2 connections if the direction is wrong — a backward fan reduces cooling effectiveness by approximately 40% and is a common cause of premature E/R trips.

9. T48 DC Link Enable Logic

T48 is the "DC 600 V ready" signal on the E/R module, and the function is identical on both 80 kW and 120 kW units:

• On the 611D bus, the drive enable signal from the SINUMERIK 840D NCU energizes the E/R's precharge command.
• The E/R closes its internal precharge contactor, charges the DC link through the precharge resistor, and monitors the link voltage.
• Once the DC link reaches the regulated 600 V, the E/R closes its main line contactor and asserts T48 to the 611D bus.
• T48 feeds the line contactor coil through a normally-open contact in the E/R's "DC bus OK" relay. The contactor will not close until the precharge is complete.
• On the 120 kW unit, the contactor will not close until the 440 V fan supply is present, because the internal fan must run before the E/R allows precharge to complete.

Verify the T48 wire is landed on the same terminal block position as on the original 80 kW unit. There is no wiring change required for the T48 circuit — the 120 kW unit is electrically compatible with the existing T48 chain. Confirm the wire gauge is at least 0.75 mm² and that the terminal is tightened to the rated torque.

The 611D bus precharge timing sequence is approximately as follows: enable command → precharge contactor closes at t = 0 ms → precharge resistor charges DC link over 1.5–2.5 s → at 580 V DC the main line contactor closes and T48 asserts → DC link reaches 600 V regulation within 200 ms. If T48 does not assert within 3 s of the enable command, the SINUMERIK 840D will alarm on drive configuration or precharge timeout. Investigate the 440 V fan supply first — it is the most common root cause.

10. SINUMERIK 840D Machine Data Update (MD1237)

SINUMERIK 840D uses machine data MD1237 ($MD_POWER_SECTION_CODE) to identify the connected drive power section. After the E/R module swap, MD1237 must be updated to the value corresponding to the 120 kW unit. If the value remains at the 80 kW code, the NCU issues a power section configuration alarm at the next NCK reset, and the drive will refuse to enable. Confirm the procedure and the current code table against the SINUMERIK 840D sl Commissioning Manual.

1. From the SINUMERIK 840D HMI, navigate to Start-up → Machine data → Drive configuration and open the MD list. Filter for MD1237 or scroll to it manually.
2. Record the current value of MD1237 in the maintenance log. This is the 80 kW power section code (an integer value as defined in the drive configuration tables; do not assume a specific value, as it depends on the drive line-up and the slot assignment).
3. Update MD1237 to the code for the 120 kW E/R module. The exact integer value is defined in the power section code tables in the commissioning manual and depends on the drive line-up, the slot assignment of the E/R module in the 611D bus, and the presence of additional 6SN1123 or 6SN1124 power modules. Do not assume a single value fits all cabinets.
4. Save the modified MD file with OK on the HMI. The HMI prompts for confirmation before writing the change to the NCK.
5. Perform an NCK reset to apply the change: Start-up → NCK reset or use the key-operated switch on the operator panel. The NCU reboots and re-reads the drive configuration.
6. After the NCK reset, verify the HMI no longer shows the power section configuration alarm. Navigate to Diagnostics → Drive system → Service display and confirm the new power section code is reported.

11. Long-Term Hardware Re-Rating for a Permanent Installation

If the 120 kW unit is to remain in service long-term (beyond an emergency production restoration), the upstream components must be re-rated to match the larger module. Operating the 80 kW line reactor and RFI filter against a 120 kW E/R for an extended period stresses the input rectifier and increases mains harmonics.

Reference the full coordination table in the Siemens SIMODRIVE 611 digital Configuring Manual. The line reactor in particular must be sized for the same uk (typically 2% at rated current) and the same current as the E/R module. An undersized reactor increases the DC link ripple and can cause the E/R to trip on overcurrent during a load transient.

12. Verification and Commissioning

1. Visual inspection. Confirm the new module is fully seated, all four M6 fixing screws are torqued to 8 Nm, all bus bar screws are torqued, all signal conductors are landed on the correct terminals, and the 440 V auxiliary feed to L1 / L2 is energized.
2. Insulation test. With the module isolated and the three-phase input shorted to PE, perform a 500 V megger test from the shorted U1 / V1 / W1 to PE. Expect > 5 MΩ. A reading below 1 MΩ indicates moisture ingress or insulation damage and requires further investigation before energizing.
3. Auxiliary fan check. Apply the 440 V AC auxiliary feed with the main disconnect still open. Verify the internal fan runs and that the rotation direction matches the arrow on the module's front panel. Reverse the L1 / L2 connections if the direction is wrong.
4. Power-up sequence. Close the main disconnect. Apply the 440 V fan feed. Apply the 840D control voltage (24 V DC to the NCU and the 611D control boards). Verify the E/R performs its self-test: internal fans ramp up, control board LEDs indicate "ready" within 10 seconds.
5. Precharge. Initiate drive enable from the 840D HMI: JOG → Drive enable. The E/R should precharge the DC link in 2–3 seconds and close the line contactor. The HMI should display "Drive system ready" and a DC link voltage of 600 V ± 5% (570–630 V).
6. MD1237 verification. Confirm the HMI Diagnostics → Drive system → Service display shows the new power section code matching the 6SN1145-1BB00-0FA1. If the old 80 kW code is still displayed, the NCK reset in Section 10 was not effective; re-do the MD1237 update and reset.
7. No-load test. Jog each axis in JOG mode at low velocity (5 mm/min for linear axes, 10 rpm for spindles). Listen for abnormal fan noise, watch for the E/R heatsink temperature to stabilize below 60 °C. Verify each axis reports a stable actual position and a stable actual current near zero.
8. Loaded test. Run a part program that exercises the spindle to its programmed load for at least 15 minutes. Monitor the E/R heatsink temperature — it should not exceed 75 °C at the rated load. If it does, the fan may be wired incorrectly, the auxiliary 440 V feed may be missing, or the cabinet ventilation may be inadequate.
9. Regenerative test. Decelerate a high-inertia axis or spindle from programmed velocity to zero. The E/R should return braking energy to the mains (regen operation). The HMI should show a brief negative DC link current spike and no alarms. If an E/R overcurrent or overvoltage alarm occurs, the regen circuit in the E/R is not functioning correctly — investigate before further operation.
10. Alarm log review. At the end of the test, review the HMI alarm log: Diagnostics → Alarm log. Confirm no drive alarms are present. Common alarm categories to watch for and their meaning:
    • 300000–300099 drive alarms: drive-level faults, usually related to encoder, motor, or power section.
    • 300500–300599 axis alarms: axis-specific faults (position lag, following error, encoder).
    • 300600–300699 communication alarms: 611D bus communication, often related to MD1237 mismatch.
    • 300700–300799 power section alarms: E/R and I/R module alarms (overtemperature, overcurrent, line contactor).

13. Risk and Caveats

• Line reactor and filter mismatch. The existing reactor and filter were sized for 80 kW. Operating the 120 kW module against an undersized reactor increases mains harmonics, stresses the input rectifier, and can cause nuisance trips on the E/R's overcurrent detection. For emergency short-term use with the same load, the existing components can remain; for permanent use, re-size to 120 kW class.
• Regenerative fault sensitivity. Larger E/R modules have lower source impedance and can return higher fault currents to the mains during a regen fault (for example, a miswired motor or a short-circuit on the DC bus). The upstream breaker trip curve may need re-coordination to ensure selective tripping.
• MD1237 mismatch latches the drive. Running the SINUMERIK 840D with the old 80 kW power section code results in a "drive not ready" condition that latches and requires an NCK reset to clear. The drive will not enable until the code is updated.
• Mechanical loading and thermal mass. The cabinet was designed for the thermal mass and weight of the 80 kW module. The 120 kW unit is approximately 15 kg heavier and dissipates more heat at the same load. Verify the cabinet backplane can support the additional weight and that the cabinet ventilation is adequate for the additional heat load. The 80 kW cabinet may require an additional extraction fan for continuous 120 kW operation.
• Warranty and conformity. Operating the drive line-up with a mismatched E/R size, line reactor, and line filter voids the Siemens warranty and may invalidate the CE conformity declaration for the drive section. Confirm acceptability with the machine builder, the system integrator, and the end user before proceeding with a permanent installation.
• EMC compliance. The RFI filter is sized for the harmonic current spectrum of the 80 kW module. The 120 kW module has a slightly different harmonic profile, and the existing filter may not attenuate the harmonics sufficiently to meet EN 61800-3 (the EMC product standard for adjustable speed drives). An EMC site survey is recommended after the swap.
• Spare parts strategy. The 120 kW unit should be returned to the spare shelf with a clear label "substitute for 6SN1145-1BB00-0EA1 — do not deploy long-term without re-rating" so that a future technician does not deploy it as a stock 120 kW part in a different drive line-up where the upstream coordination is unknown.

14. Frequently Asked Questions