Yaskawa GA800 E07 Fault — What It Means
The E07 fault on a Yaskawa GA800 variable frequency drive indicates a serial communication transmission error. The drive is not receiving valid communication on the option or serial link. This typically occurs when the communications cable is disconnected, wired incorrectly, shorted, or when an expected option module is missing or not being detected properly.
This fault does not point to motor problems, overload conditions, or power stage failures. It is strictly a communications path issue between the drive and its serial or network option hardware. The drive expects to exchange data over a cable or module and is not seeing the expected signal.
Common Causes
- Disconnected or loose communications cable The serial or option cable is unplugged, not fully seated in the terminal, or has a loose connection at the drive or option module end.
- Incorrect wiring of the communications link The cable is wired to the wrong terminals or does not match the pinout diagram for the installed option module.
- Damaged or shorted communications cable The cable harness has a short circuit, open conductor, or physical damage that prevents valid signal transmission.
- Missing or failed option module The serial or network option board that the drive expects to communicate with has been removed or has failed internally.
- Faulty drive communications interface If cable and module checks pass, the drive’s internal communications hardware may be damaged or defective.
Step-by-Step Fix
- De-energize the drive following lockout/tagout procedure and wait for all capacitors to discharge before opening the enclosure or touching any wiring.
- Inspect the communications cable and connectors at both ends for loose plugs, broken wires, bent pins, or obvious physical damage, and reseat any connectors that are not fully engaged.
- Verify the wiring matches the correct diagram for your installed option module by consulting the option manual or wiring schematic, and correct any miswired terminals.
- Check the cable for continuity and shorts using a multimeter, testing each conductor end-to-end and between conductors to identify any opens or short circuits, then repair or replace the cable if faults are found.
- Confirm the option module is installed and secure in its slot, remove and reseat it if present, or install a replacement module if it was removed or is suspected to have failed.
- Restore power to the drive and observe whether the E07 fault clears, then test basic communication function through the option link if the fault is gone.
- Contact Yaskawa technical support if the fault persists after cable and module replacement, providing the drive model number, serial number, and a description of all checks performed so far.
Parts Often Needed
| Part | Notes |
|---|---|
| Communications cable for Yaskawa GA800 option module | Amazon | Match the cable type and pinout to your specific option board model. |
| Yaskawa GA800 serial or network option module | Amazon | Verify the correct option board part number for your application before ordering. |
When to Call a Pro
Call a qualified industrial electrician or automation technician if you are not trained in lockout/tagout or VFD service, if the fault persists after you have verified and replaced the cable and option module, or if you do not have access to the correct wiring diagrams for your installed option hardware. Yaskawa technical support or an authorized distributor can provide advanced diagnostics and factory-level troubleshooting when communication faults do not resolve with field-replaceable parts.