Old Version Psu2 Power Supply Unit/Board 6SE7038-6GL84-1JA1 6SE7 038-6GL84-1JA1 6SE7O38-6GL84-1JA1 6SE70386GL841JA1

Siemens 6SE7038-6GL84-1JA1 | SIMOVERT MASTERDRIVES PSU2 Power Supply Board — Design J to M Large Chassis

Part Number: 6SE7038-6GL84-1JA1

Manufacturer: Siemens AG (Germany)

Product Type: PSU2 — Internal Auxiliary Power Supply Board (Spare Part) 

The Internal Power Foundation of a Large-Frame Drive

The 6SE7038-6GL84-1JA1 is the PSU2 — the internal auxiliary power supply board inside large SIMOVERT MASTERDRIVES chassis units. In Design J through M drives, the PSU2 converts the available power source into the multiple regulated DC rails that run everything inside the drive: the control processor, the gate drive bias supplies for multiple parallel IGBT assemblies, fault monitoring circuits, and the cooling fan control system.

Without a functioning PSU2, the drive is completely inert. No display, no fans, no relay action — despite the AC supply being present and correct. This is the defining symptom of PSU2 failure, and it distinguishes a PSU2 fault from most other drive faults, which typically allow at least a partial startup before failing.

Designs J through M are the largest physical formats in the SIMOVERT 6SE70 range — the drives found in rolling mills, heavy cranes, cement and mining mill drives, large centrifuge systems, and ship propulsion applications. At this scale, the multiple parallel IGBT assemblies each need their own isolated gate supply. The PSU2 is sized for these expanded auxiliary power demands, which is why it differs from the PSU1 board used in smaller SIMOVERT chassis.

How PSU2 Failure Presents

Three recognisable patterns cover most PSU2 failures:

Complete non-response at power-on. Display blank, fans silent, no relay. The drive is dark despite confirmed AC input. This is a full PSU2 output failure — the most common presentation.

Intermittent hardware fault codes at startup. The drive initiates its boot sequence, then trips. The PSU2 is producing voltage, but with ripple or brief dropout that the drive's internal monitoring catches before a stable run state is established.

Cooling fault without other issues. If the PSU2's fan supply output fails while the control supply remains functional, the cooling system stops while the drive appears otherwise normal. The drive then trips on heatsink overtemperature once the thermal margin is consumed under load.

Confirming which output has failed requires measuring PSU2 output voltages with the drive energised under controlled conditions and full high-voltage safety compliance.

High-Voltage Safety — Non-Negotiable

Design J through M SIMOVERT drives contain large DC bus capacitor banks that retain dangerous voltage after AC isolation. The minimum discharge waiting period after mains isolation is five minutes — the DC bus voltage must be confirmed below 50V with a calibrated instrument before any internal access. Work on these units must comply with site high-voltage safety procedures. Only trained, authorised personnel should perform internal access or board-level service.

Key Specifications

FAQ

Q1: The large SIMOVERT shows no response at power-on — display blank, fans silent. Diagnostic sequence?

Confirm AC supply voltage at drive input terminals is within range, all fuses and breakers are intact, and isolation switches inside the cabinet are closed. With AC supply confirmed, measure PSU2 output voltages at the board's output connectors. Zero output with confirmed AC input points directly to PSU2 failure.

Q2: Does the 6SE7038-6GL84-1JA1 work in all SIMOVERT MASTERDRIVES chassis sizes?

No. The PSU2 covers Designs J through M. Smaller SIMOVERT chassis use PSU1 (or other PSU variants) matched to their lower auxiliary power demands. Confirm the drive's design designation from its rating plate before ordering — using a PSU board from a different design range produces incorrect auxiliary voltages.

Q3: Drive restarts after PSU2 replacement but trips on F030 after a few minutes. Is the new PSU2 still the issue?

Possibly. F030 after a successful restart suggests the replacement PSU2 may be delivering marginal voltage under load — adequate at startup but sagging when the drive's internal load increases. Measure PSU2 output voltages under running conditions. If within specification, the F030 may be a pre-existing issue — a gate drive board, control board, or temperature monitoring fault — that was masked by the PSU2 failure and is now visible.

Q4: An 18-year-old J-frame drive with a first PSU2 failure — replace board or the whole drive?

A first PSU2 failure after 18 years of reliable service does not necessarily indicate a failing drive. IGBT modules in well-cooled drives can last 20+ years. However, DC bus capacitors at this age should be inspected — measure capacitance and ESR. If capacitors are borderline, replacing PSU2 plus preventive capacitor replacement may be more cost-effective than full drive replacement. If the drive has had multiple recent failures, evaluate the total maintenance cost trajectory against a SINAMICS migration.

Q5: Can the 6SE7038-6GL84-1JA1 be repaired rather than replaced?

Board-level repair by a qualified power electronics technician is viable for common failure modes: failed electrolytic capacitors, blown fusible links, and failed discrete semiconductors. Professional drive repair shops offer this service. Repair is typically faster and cheaper than sourcing a replacement board when stock is limited. The repaired board should be load-tested before return to a production drive.