Sinamics G150 CU320 CU320-2 CIB CIM Board Compatibility Guide

1. Overview

The SINAMICS G150 is a chassis-type, air-cooled low-voltage drive from Siemens used for variable-speed control of three-phase induction and synchronous motors in pumps, fans, compressors, extruders, and similar industrial loads. The drive is shipped as a ready-to-connect cabinet unit, split into a Control Unit (CU) and a power block (the chassis power unit). Two Control Unit generations coexist in installed fleets: the legacy CU320 on firmware platform V2.x and the current CU320-2 on firmware platform V4.x / V5.x. The power block itself exists in two revisions — the older ...AA0 and the newer ...AA3 — each with a different control interface board (CIB vs. CIM). Cross-generation substitution is the source of most G150 service questions, and the answer is governed by the firmware platform, the chassis revision, and which interface board is installed.

2. Sinamics G150 Drive Family Architecture

The G150 is structured around three primary assemblies that must be kept in agreement when spares are ordered or a service replacement is performed:

• Power block (chassis power unit): houses the line-side rectifier, DC link capacitors, and the inverter IGBT module. Identified by the part-number family 6SL3310-...AAx.
• Control Unit: the digital controller that runs the closed-loop algorithms, communication stacks, and the I/O image. Identified by the part-number family 6SL3040-0MAxx (CU320) or 6SL3040-1MAxx (CU320-2).
• Operator panel and option modules: AOP30 advanced operator panel, PROFIBUS / PROFINET communication modules (CBE20, CBE25), encoder evaluation (SMC10/SMC20/SMC30), and TM31/TM15 terminal modules.

The interface between the Control Unit and the power block is the critical link. In legacy designs this is the Control Interface Board (CIB), fed by a separate Power Supply Board (PSB). In newer designs the equivalent function is provided by the Control Interface Module (CIM) together with the Interface to Power Driver (IPD). Mixing the two interface families without verifying firmware support produces a non-functional drive and is the most common reason for the symptom described in the source: a G150 with an AA0 chassis and a CU320 V2.06 where a service engineer needs to know whether an AA3 power block and a CIM can be installed without changing the Control Unit.

3. Control Unit Generations: CU320 vs. CU320-2

3.1 CU320 (Legacy Control Unit)

• Article-number family: 6SL3040-0MA00-0AA0 (PROFIBUS DP variant) and 6SL3040-0MA01-0AA0 (PROFINET variant). Specific options and firmware states are encoded in the suffix.
• Firmware platform: V2.x — typically V2.4, V2.5, V2.6, and V2.6 SP1. V2.6 SP1 is the first release that supports the AA3 chassis.
• Communication: PROFIBUS DP on board, PROFINET via CBE20 option module.
• Option slots: one CU slot, two option slots. The BOP20 basic operator panel or the AOP30 advanced operator panel can be plugged in directly.
• Memory card: CompactFlash card (typically 512 MB or 1 GB), order code 6SL3054-0xx00-1BA0 family.
• Engineering tool: STARTER V4.x (and the legacy Drive ES).

3.2 CU320-2 (Current Control Unit)

• Article-number family: 6SL3040-1MA00-0AA0 (PROFIBUS DP), 6SL3040-1MA01-0AA0 (PROFINET, two-port). The PROFINET variant integrates CBE25 functionality.
• Firmware platform: V4.x and V5.x. Common releases: V4.4, V4.5, V4.6, V4.7, V4.8, V5.1, V5.2, V5.3. Each release adds safety, communication, or motor-control features.
• Performance: approximately 3× the computation capacity of the legacy CU320. Required for high-speed encoder evaluation, PROFIsafe over PROFINET, and modular Safety Integrated functions.
• Option slots: two option slots, supporting CBE20, CBE25, TM31, TM15, and encoder modules.
• Memory card: SINAMICS CF card, 1 GB or 8 GB, order code 6SL3054-0xx01-1BA0 family.
• Engineering tools: STARTER V5.x or SINAMICS Startdrive integrated with TIA Portal.

4. Interface Boards: CIB, CIM, IPD, and PSB

All four boards are 100 mm × 160 mm-class plug-in modules mounted inside the G150 power block, between the inverter IGBT modules and the Control Unit cabinet door. Each has a defined function that must be replaced with the equivalent module of the same generation — the modules are not pin-compatible with one another.

4.1 CIB (Control Interface Board)

The CIB is the legacy interface board on AA0 chassis. Its tasks are:

• Carrying the fiber-optic links to the IGBT gate-driver boards (TX and RX pairs per phase leg)
• Reading the inverter module temperature sensors (NTC / PT1000 inputs)
• Receiving the power-module status flags and the DC-link voltage feedback
• Distributing the auxiliary 5 V, 15 V, and 24 V rails supplied by the PSB

Article-number family: 6SL3055-0AA00-2xxxx. The exact suffix depends on the power class. The CIB is keyed to the AA0 mechanical layout and cannot be plugged into an AA3 chassis backplane.

4.2 CIM (Control Interface Module)

The CIM is the successor to the CIB. It performs the same fundamental function — interfacing the Control Unit to the power block gate drivers — but with the following differences:

• Higher-bandwidth fiber-optic links capable of carrying the additional diagnostic data of the AA3 inverter modules (gate-health, switching-cycle count, per-leg temperature)
• Two independent 24 V supply inputs for redundant auxiliary power
• No internal power-supply section; the CIM requires a separate power source, normally the IPD
• Direct-mount fiber-optic connectors with latching mechanism (no separate optical adapters)

Article-number family: 6SL3040-0PA00-0AA0 (the suffix varies with the power class). The CIM is the right-hand module when viewed from the front of the AA3 chassis.

4.3 IPD (Interface to Power Driver)

The IPD is required whenever a CIM is used. It performs four functions:

1. Generates the isolated 5 V, 15 V, and 24 V rails for the CIM and the IGBT gate drivers
2. Routes the fiber-optic transmit and receive pairs from the CIM to the gate-driver boards
3. Provides the hardware-coded chassis identification (a resistor matrix read by the CIM to identify the AA3 power-class)
4. Hosts the DC-link voltage divider and the analog front end for the DC-link measurement

Article-number family: 6SL3055-0AA00-2xB0 family. The IPD has a green status LED that must be lit when the Control Unit is powered.

4.4 PSB (Power Supply Board)

The PSB exists only on AA0 chassis. It is a single board that takes the 24 V from the cabinet supply and generates the rails for the CIB. On AA3 chassis the equivalent function is absorbed into the IPD plus a chassis-mounted 24 V power supply. The PSB cannot be used to feed a CIM, and the IPD cannot be plugged into an AA0 backplane.

5. Chassis Power Unit Generations: AA0 vs. AA3

The G150 power block is identified by the part-number suffix. The 6SL3310-... power blocks use the following revisions:

The mechanical outline, fixing centers, and motor-connection footprint are identical between AA0 and AA3 of the same power class, which is why the AA3 is offered as a drop-in spare for the AA0. The electrical interface to the Control Unit, the gate-driver optical cables, and the firmware platform differ.

6. Compatibility Matrix

The compatibility matrix, derived from the SINAMICS G150 Operating Instructions, the CU320-2 List Manual, and confirmed by the service experience summarized in the field report, is as follows:

Key conclusions:

• The CU320-2 cannot operate an AA0 chassis. The V4.x/V5.x firmware does not contain the CIB driver or the AA0 chassis identification code.
• The CU320 can operate an AA3 chassis, but only with firmware V2.6 SP1 or later. The AA3 chassis is then driven through the CIM + IPD, not the CIB.
• Loading V2.x firmware onto a CU320-2 is impossible; loading V4.x/V5.x firmware onto a CU320 is impossible. The two Control Units are not interchangeable by firmware alone.
• There is no CIB-to-CIM translator board. If the AA3 chassis is installed, the CIM and IPD must be installed, and the original CIB + PSB are removed and discarded.

7. Spare Part Substitution Scenarios

The case in the source is a 6SL3710-1GE33-1AA0 (380–480 V three-phase, 315 kW AA0 chassis) with a CU320 on V2.06, and a spare 6SL3310-1GE33-1AA3 (the equivalent AA3 power block) plus a spare CIM module. The user asks whether the CU320 must be replaced by a CU320-2 to use the AA3 power block and the CIM.

7.1 Scenario A — Keep the CU320 V2.06, install the AA3 power block and the CIM

Valid only if the CU320 firmware is upgraded to V2.6 SP1 or later. V2.06 is an early V2.6 release that does not include AA3 chassis support; the SP1 add-on must be loaded. The required steps are:

1. Upgrade the CU320 firmware from V2.06 to V2.6 SP1 (or the latest V2.x available on the Siemens support portal).
2. Replace the CIB + PSB with the CIM + IPD. The original CIB and PSB are scrapped.
3. Re-route the gate-driver fiber-optic cables to the CIM connectors. The AA3 fiber layout is different from the AA0 layout; re-pin per the AA3 wiring diagram.
4. Re-commission with STARTER. Carry out a factory reset (p0010 = 30, p0970 = 1), then re-load the project.
5. Verify the power-unit identification in r0203 and r0204 matches 6SL3310-1GE33-1AA3.

Result: the AA3 chassis is operational on the original CU320. The CU320-2 is not required.

7.2 Scenario B — Replace the CU320 with a CU320-2, install the AA3 power block and the CIM

Required if the user wants to move to the V4.x/V5.x firmware platform. The steps are:

1. Source a CU320-2 (DP variant 6SL3040-1MA00-0AA0 or PN variant 6SL3040-1MA01-0AA0).
2. Move the existing CompactFlash card contents to the new SINAMICS CF card (the CU320-2 will not read a CU320 CF card directly; a STARTER project upload / download is required).
3. Install the AA3 power block, CIM, and IPD.
4. Load the V4.x or V5.x firmware on the CU320-2 and re-commission.

This scenario is necessary if the customer wants Safety Integrated (PROFIsafe), Startdrive/TIA Portal integration, or the higher dynamic response of the V4.x control algorithms. If those are not required, Scenario A is more economical.

7.3 Scenario C — Replace only the interface board (CIB → CIM) without changing the power block

Not supported. A standalone CIM-for-CIB swap on an AA0 chassis is not possible: the AA0 backplane does not have the IPD mounting position, the AA0 power-module temperature sensors route to a different connector, and the AA0 gate-driver optical connectors are not on the CIM pinout. The CIM can only be installed together with an AA3 chassis.

8. Retrofitting from CIB to CIM

Siemens documents the CIB → CIM retrofit as a factory-recommended service operation, not a customer field modification. The procedure is as follows:

1. Power down the drive, open the cabinet, and apply the site lock-out/tag-out procedure. Verify zero voltage on the DC-link test points with a CAT III 1000 V meter before touching any internal component.
2. Wait a minimum of five minutes after power-down for the DC-link capacitors to discharge (the G150 internal discharge resistors take 3–5 minutes to drop the DC link below 50 V).
3. Remove the existing CIB and PSB from the AA0 chassis position. These parts are scrapped.
4. Mechanically mount the IPD in the IPD position on the AA3 chassis (the AA3 chassis has the IPD mounting holes; the AA0 does not). The AA3 is installed in place of the AA0 at this point.
5. Mount the CIM above the IPD and connect the IPD-to-CIM ribbon.
6. Route the fiber-optic cables from the CIM to the AA3 gate-driver boards. The cable kit is chassis-specific; use the kit supplied with the AA3 spare part.
7. Connect the 24 V supply feed to the IPD.
8. Update the Control Unit firmware to V2.6 SP1 minimum (CU320) or V4.x (CU320-2).
9. Re-commission with STARTER. Perform a factory reset, re-load the project, and run the motor identification at standstill (p1910) followed by the rotating measurement (p1960) if the application allows.
10. Run the drive in no-load jog mode, then at low speed with motor coupled, and verify the current symmetry, the DC-link voltage, and the heatsink temperature ramp.

9. Firmware Platform Requirements

The firmware-to-software relationship is fixed by the boot loader of the Control Unit. The supported pairings are:

The firmware version is read at parameter r0018 and the power-unit identification at r0203 / r0204. The chassis selection is at p0251. A mismatch between p0251 and the installed chassis raises fault F07802 at the first ON command.

10. Commissioning and Parameter Verification

After any Control Unit or interface board change, perform the following verification sequence:

1. Power up the Control Unit only (24 V on, main contactor open). Confirm STARTER or Startdrive connection via PROFIBUS, PROFINET, or the Ethernet service interface.
2. Confirm p0010 = 0 (drive is in ready state, not in commissioning mode).
3. Read r0018 and confirm the expected firmware version. For the source case, the target is V2.6 SP1 or later on the CU320.
4. Read r0203 (power unit code number) and r0204 (power unit article number) and confirm the value matches the part number printed on the power block nameplate (for the source case, 6SL3310-1GE33-1AA3).
5. Set p0251 to the matching chassis code. Save to RAM and ROM.
6. Run the drive in no-load jog mode from the AOP30 or STARTER to confirm gate-driver response. Listen for a smooth 0 Hz buzz; any ticking noise indicates a fiber-optic polarity reversal.
7. Apply main power. Run the drive to a low reference speed (5 Hz) and check the motor current symmetry in r0027 (absolute current actual value) and r0030 (current setpoint). The asymmetry must be below 5 %.
8. Run the motor identification at standstill (p1910 = 1, then p1900 = 2 to start) followed by the rotating measurement (p1960 = 1) if the application allows uncoupled rotation.
9. Save the project to the CF card using the "Copy RAM to ROM" function (p0977 = 1).

11. Fault Diagnostics and Common Issues

The following faults and warnings are the most common indicators of a control unit / interface board mismatch or wiring error:

Diagnostic flow when a fault appears after a CIB-to-CIM swap:

1. Confirm p0251 matches the installed chassis (read the chassis code from the power block nameplate).
2. Confirm r0203 matches the printed part number on the power block nameplate.
3. Confirm r0018 matches the expected firmware (V2.6 SP1 or later for CU320; V4.x or V5.x for CU320-2).
4. Inspect the fiber-optic connections at the CIM for bent fibers, contaminated ferrules, or reversed TX/RX polarity. The TX port of the CIM feeds the RX port of the gate driver and vice versa; the connectors are colour-coded but always verify with the wiring diagram.
5. Verify the IPD 24 V supply is present (green LED on the IPD module) and that the IPD-to-CIM ribbon is fully seated.
6. Verify the CIM fiber-optic transmit and receive indicators (yellow LEDs on the CIM) flash at the boot-up handshake with the Control Unit.
7. If all of the above are correct, re-load the firmware to the Control Unit to clear any corrupted parameter image, then re-commission.

12. Field Replacement Procedure Summary

Concise field procedure for a G150 power block swap with interface board change (CU320 retained):

1. Lock out and tag out the drive per site EHS procedure.
2. Wait for the DC link to discharge (3 to 5 minutes, per cabinet label).
3. Remove the Control Unit from the cabinet door (the CU door mount is keyed to a single position; do not force).
4. Disconnect the CIB ribbon cable and the PSB 24 V feed at the power block.
5. Remove the AA0 power block and lift out on the rated hoist.
6. Mount the AA3 power block. Torque the busbar bolts to the value printed on the busbar label (typically 35 Nm for 315 kW).
7. Install the IPD in the IPD position on the AA3 chassis.
8. Install the CIM above the IPD; connect the IPD-to-CIM ribbon and the 24 V feed.
9. Route the fiber-optic cables from the CIM to the AA3 gate drivers per the AA3 wiring diagram.
10. Reinstall the Control Unit on the door mount.
11. Power up the Control Unit only; verify STARTER connection and read r0018 / r0203.
12. Load the latest V2.6 SP1 (or V2.x) firmware onto the CU320 if not already at that level.
13. Re-commission per the sequence in section 10.
14. Save to the CF card and to the backup project on the engineering PG.

13. Notes on Documentation and Service Sources

The primary reference documents for the G150 are the Operating Instructions, the List Manual, and the CU320-2 Function Manual, all available on the Siemens Industry Online Support portal. The part-number suffix and the firmware release notes are the authoritative sources for compatibility; this article summarises the working rules but does not replace those documents. When ordering spare parts, always quote the article number exactly as printed on the power block nameplate and the firmware release noted on the Control Unit label. Order the CIM and IPD as a matched pair from the same release batch to avoid the 1 % mix of revisions where the IPD hardware-coding does not match the CIM.