Absorption Board /Surge Protection Board 6SE7038-6EK84-1GF0 6SE70386EK841GF0 6SE7O38-6EK84-1GFO 6SE7 038-6EK84-1GF0

Siemens 6SE7038-6EK84-1GF0 | SIMOVERT MASTERDRIVES Inverter Snubber Module SMU3 — Base Device Spare Part

Part Number: 6SE7038-6EK84-1GF0

Manufacturer: Siemens AG (Germany)

Product Type: SMU3 — Inverter Snubber Module (Inverter Protection Circuit) 

What a Snubber Module Does

The 6SE7038-6EK84-1GF0 is the SMU3 — the Inverter Snubber Module for the base device position in large SIMOVERT MASTERDRIVES chassis inverters. The SMU3 is a protection circuit. Its function is to suppress the voltage transients (voltage spikes) that appear across the IGBT transistors every time they switch.

Every IGBT turn-off event generates an inductive voltage spike proportional to the rate of current change and the circuit stray inductance. Without snubber suppression, these spikes can reach levels that exceed the IGBT's breakdown voltage and destroy the device. The SMU3 absorbs the spike energy through its snubber capacitors and resistors, clamping the voltage at a safe level and protecting the IGBT.

In the 6SE7038-6EK84 electronics assembly, 12 SMU3 boards are used per converter configuration. The base device units (1GF0 suffix) mount in the lower positions; the upper units use the companion board 6SE7038-6GK84-1GF0. Both are required for complete IGBT protection across all switching positions.

SMU3 in the Board Family

Key Specifications

FAQ

Q1: The SIMOVERT shows IGBT overcurrent or overvoltage fault. Could the SMU3 snubber module be the cause?

Yes. A failed SMU3 loses its voltage clamping function — the IGBT it protects then sees unattenuated switching spikes, which can trigger overvoltage protection or cause IGBT failure. Before blaming the IGBT, inspect all SMU3 boards for burnt components or damaged snubber capacitors. A visually intact SMU3 can still have failed capacitors — measure ESR before concluding the boards are good.

Q2: The drive uses 12 SMU3 units. If one fails, must all 12 be replaced?

No — like-for-like replacement of the single failed unit is the standard approach. However, if the SMU3 failure is associated with an IGBT switching event that caused abnormal transients, inspect adjacent boards in the same switching leg for secondary damage before returning to service.

Q3: What is the difference between 6SE7038-6EK84-1GF0 (SMU3 base) and 6SE7038-6GK84-1GF0 (SMU3 upper)?

Both are SMU3 snubber modules, but they serve different physical positions within the IGBT assembly — base (lower) and upper positions in the inverter stack. They are not interchangeable between positions. When ordering a replacement, confirm which position the failed board occupied.

Q4: The 6SE7038-6EK84-1GF0 is discontinued. Is it available in the aftermarket?

Specialist SIMOVERT MASTERDRIVES spare parts companies hold exchange stock for this snubber module. Confirm the 1GF0 suffix (base position) specifically — the upper position (6GK84-1GF0) is a different board. Request a functional test certificate before accepting the unit.

Q5: Can the SMU3 be replaced without discharging the DC bus?

No. The SMU3 is in direct electrical contact with the drive's DC bus. The DC bus must be completely discharged and verified at zero volts with a calibrated voltmeter before any SMU3 board is handled. Allow the minimum specified discharge time after isolating the AC supply before touching any bus-connected components.