Original SIEMENS RC Absorption Board 6SE7038-6EK84-1GG0 6SE70386EK841GG0 6SE7O38-6EK84-1GGO 6SE7 038-6EK84-1GG0

Siemens 6SE7038-6EK84-1GG0 | SIMOVERT MASTERDRIVES Inverter Snubber Module — SMU3 / Inverter Protection Circuit / Spare Part

Snubber Modules in SIMOVERT MASTERDRIVES — DC Bus Protection at the Switching Level

The 6SE7038-6EK84-1GG0 is an inverter snubber module for Siemens' SIMOVERT MASTERDRIVES variable speed drive platform — the high-power industrial VFD range used in demanding process, crane, and heavy machinery applications. Snubber modules serve a specific and critical function inside the MASTERDRIVES' inverter section.

Each time an IGBT transistor in the inverter bridge switches, it interrupts current through a circuit that contains both intended and parasitic inductance. When current is interrupted abruptly, energy stored in those inductances forces a voltage spike — a transient that appears across the IGBT and on the DC bus. If uncontrolled, these spikes exceed the IGBT's safe operating voltage and cause transistor failure.

The snubber module absorbs and dissipates these transients through its RC (resistor-capacitor) snubber circuit. The capacitors absorb the spike energy; the resistors dissipate it as heat. Without functional snubbing, each switching event stresses the IGBTs incrementally, eventually causing premature transistor failure. The SMU3 designation identifies the snubber assembly configuration for the 6SE7038 chassis within the MASTERDRIVES product family. The "1GG0" suffix specifies the base design variant of this module.

Key Specifications

Adjacent Module Types — Confirm the Correct Variant

Within the 6SE7038-6EK84 range, multiple related modules serve different positions in the inverter protection assembly:

These modules are not interchangeable — each occupies a defined position in the drive's protection circuit. Confirm the exact part number from the installed module's label.

FAQ

Q1: What does a snubber module do in a MASTERDRIVES inverter?

The snubber RC circuit absorbs the voltage spike generated each time an IGBT transistor switches off — the energy stored in circuit inductances causes a voltage transient that the snubber dissipates in its capacitor and resistor elements. Without this protection, switching transients can exceed the IGBT's rated voltage and cause transistor failure over time.

Q2: Can the 6SE7038-6EK84-1GG0 be replaced without de-energising the drive?

No. Replacing any inverter-section component requires full drive de-energisation — mains power disconnected and DC bus capacitors fully discharged. DC bus voltage in a 380–480V MASTERDRIVES can reach approximately 680V DC and retains this charge for several minutes after disconnection. Verify DC bus voltage at the bus terminals with a high-voltage rated voltmeter before opening the drive or touching any internal component.

Q3: How is snubber module failure diagnosed?

A failed snubber typically shows no obvious external damage — diagnostic symptoms appear in the inverter's behaviour. Repeated IGBT failures or increasing DC bus overvoltage trips during switching suggest loss of snubber protection. Physical inspection of the module for burned resistors, cracked capacitors, or damaged substrate confirms failure. A drive that operated reliably for years but now repeatedly trips on overvoltage should have the snubber modules inspected.

Q4: What is the connection between the -1GG0 and -1GF0 suffix variants?

The suffix encodes Siemens' MLFB product configuration system — different letters in the terminal suffix identify design variant revisions or parallel upper/lower module types within the same snubber assembly. Both -1GG0 and -1GF0 are base design variants; their specific functional differences are defined in the SIMOVERT MASTERDRIVES spare parts documentation. Confirm which suffix is installed from the module label.

Q5: Where is the 6SE7038-6EK84-1GG0 sourced?

Through Siemens' MASTERDRIVES spare parts supply and through the SIMOVERT MASTERDRIVES aftermarket — Siemens industry service centres and specialist MASTERDRIVES spare parts dealers. Confirm the -1GG0 suffix from the installed module's label. Adjacent 6SE7038-6EK84 suffix variants serve different positions in the inverter protection assembly and must not be substituted without confirming equivalence.