Yaskawa GA800 E97 Fault Code — What It Means
The E97 fault code on a Yaskawa GA800 variable frequency drive indicates a serial communication transmission error. The drive is not receiving valid data on its communications line, pointing to a problem in the cable, wiring, or connection path rather than a motor or power-stage issue.
This fault is triggered by incorrect comms wiring, a short circuit in the communications cable, or a disconnected or improperly connected cable. It does not indicate a motor overload, inverter problem, or internal drive failure. The fault directs attention to the physical communication link between the drive and the master controller or network device.
Before You Replace Anything
Technicians sometimes replace the communications option card or the drive itself before verifying the cable. Always test the communications cable for opens, shorts, and correct wiring first, since cable faults cause the majority of E97 errors.
Common Causes
- Incorrect comms cable wiring The communications cable is wired to the wrong terminals or has reversed polarity, preventing valid data transmission.
- Short circuit in the communications cable Damaged insulation or pinched conductors create a short between wires, blocking communication signals.
- Disconnected or loose cable connection The communications cable is not fully seated at the drive or controller end, or has been pulled loose during maintenance.
- Broken or open conductor in the cable A wire inside the cable is broken or has an open connection, interrupting the signal path between drive and controller.
- Failed communications interface hardware The communications option card in the drive or the external comms device has failed, though this is less common than cable issues.
- Environmental damage to the cable Heat, moisture, or physical wear has degraded the cable insulation or conductors over time, causing intermittent or permanent faults.
Quick Diagnosis
Answer these to narrow it down fast.
Is the communications cable firmly seated at both the drive and the controller or network device?
No: Reseat the cable at both ends, clear the fault, and test communication again. Many E97 faults resolve with a proper connection.
Does a multimeter continuity test show an open or short in the communications cable?
No: The cable tests good, so verify the wiring matches the GA800 terminal diagram and check the communications option hardware or controller.
Does the fault clear and stay clear after verifying correct wiring and replacing any damaged cable?
No: The fault persists with known-good wiring and cable, so suspect the communications option card, the master controller, or network-side issues. Contact Yaskawa support with model, serial number, and failure details.
Step-by-Step Fix
- Power down the drive and lock out the supply circuit before touching any wiring or connections.
- Identify the communications path by consulting the GA800 wiring diagram and the option manual for your specific network or protocol (Modbus, DeviceNet, EtherNet/IP, etc.).
- Inspect both ends of the communications cable at the drive terminals and the controller or network device, looking for loose connectors, damaged pins, or incomplete seating.
- Check the cable routing along its entire length for pinch points, cuts, burned insulation, or areas exposed to heat, moisture, or mechanical wear.
- Test the cable with a multimeter by disconnecting both ends and measuring continuity on each conductor end-to-end, and checking for shorts between conductors and ground.
- Correct any wiring errors by comparing your actual connections to the terminal assignment in the GA800 manual, and reseat or replace any damaged connectors.
- Clear the E97 fault from the drive’s display, restore power, and test communication under normal operating conditions to confirm the fault does not return.
- Escalate to Yaskawa support if the fault remains after confirming correct wiring and a known-good cable, providing the drive model, serial number, option card type, and details of the communication network.
Parts Often Needed
| Part | Notes |
|---|---|
| Communications cable (shielded twisted-pair or network-specific) | Amazon | Match the cable type and pinout to your GA800 option card and network protocol. Consult the option manual for gauge and shield requirements. |
| Communications option card (if hardware fault confirmed) | Amazon | Order the correct Yaskawa option card for your network (Modbus, DeviceNet, EtherNet/IP, etc.). Confirm the part number with Yaskawa support before purchasing. |
When to Call a Pro
Call a qualified drives technician or controls integrator when the E97 fault persists after you have verified correct wiring and replaced the communications cable. Diagnosing option-card failures, network-side faults, and controller issues requires specialized test equipment and knowledge of industrial communication protocols. Always have the drive model number, serial number, option card type, and a description of the network architecture ready when contacting Yaskawa support or a certified service provider. Do not attempt to replace internal option hardware or modify firmware without proper training.
Rough cost: A pro service call runs about $150–400 depending on cable length and labor.