E.1

Option Fault / Internal Contact Failure

Mitsubishi Electric · Mitsubishi FR-E800 Variable Frequency Drive

What does E.1 mean?

The inverter output is shut off due to a contact failure between the inverter and a plug-in option, or if a manufacturer setting switch on the plug-in option has been altered. Excessive electrical noise around the inverter can also contribute to this fault. This compromises the functionality of the plug-in option.

Common Causes

  • Loose or improperly seated plug-in option board (e.g., communication card, I/O card) causing intermittent contact.
  • Manufacturer setting switch (DIP switch) on the option board altered from default or required position.
  • Excessive electromagnetic interference (EMI) or radio frequency interference (RFI) affecting the internal communication bus.
  • Damaged connector pins on either the inverter's option slot or the plug-in option board.
  • Faulty internal circuit on the plug-in option board.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Power down the inverter and physically re-seat the plug-in option board firmly into its slot.

  2. 2

    Verify the position of all manufacturer setting switches (DIP switches) on the option board against the option board's instruction manual.

  3. 3

    Inspect the option board connector pins and the inverter's option slot for any signs of damage, bending, or foreign material.

  4. 4

    Check for proper grounding of the inverter chassis and all connected external equipment, ensuring ground resistance is below 1 Ohm.

  5. 5

    Route control wiring (e.g., communication cables) separately from power wiring (e.g., motor cables) by at least 30 cm to reduce EMI.

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Verified technical data. Last updated: March 2026

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Source: Mitsubishi FR-E800 Variable Frequency Drive