Troubleshooting Panasonic MINAS A6 Servo Alarm Err 16.0 (Overload) and Auto-Gain Tuning via PANATERM
1. Internal Logic of Panasonic Err 16.0 (Overload Protection)
In Panasonic MINAS A6 and A5 servo drives, trip code Err 16.0 (Overload Protection) protects stator windings from thermal destruction via an integrated software $I^2 t$ thermal model. When continuous current demand exceeds 100% rated limits over time (e.g. 200% current sustained for > 10 seconds or 300% current for > 2 seconds), the drive trips into fail-safe lockout. Common Root Causes: 1. Mechanical Binding: Seized ballscrew bearings, unlubricated linear rails, or incomplete electromagnetic brake release. 2. Parameter Mismatch: Improperly identified load inertia ratio (Pr0.04), forcing control loops into violent hunting oscillations. 3. Physical Obstruction: The axis stalled against an unyielding mechanical hard stop.
2. Systematic Physical Isolation Protocol
- Verify Electromagnetic Holding Brake (24VDC): On vertical Z-axes, measure voltage directly across brake coils under servo-on conditions. Ensure a full 24VDC ±10% is present. Contact resistance in auxiliary relays causes partial brake drag, inducing severe thermal overload.
- Uncouple Motor from Mechanical Transmission: Decouple flexible couplings or timing belts. Manually sweep the ballscrew/slide by hand across its full envelope. Any localized stiffening denotes mechanical guideway binding.
- Perform Unloaded Motor Jog: Command motion on the decoupled bare motor. If current draws settle to baseline (< 5%) without tripping, the drive electronics and motor windings are confirmed sound; the root cause is external load resistance.
3. PANATERM Real-Time Auto-Gain Tuning Workflow
Connect a PC via standard USB to the MINAS A6 drive and launch PANATERM v6: 1. Access the Auto-Tuning utility, selecting Real-Time Auto Tuning (Pr0.02 = 1). 2. Select mechanical Machine Rigidity: establish level 11 to 13 for standard slides, or 14 to 16 for high-stiffness gantries. 3. Cycle normal production trajectories. PANATERM's internal estimator continuously tracks load dynamics, populating Pr0.04 (Inertia Ratio) dynamically (e.g. 250% confirms load inertia is 2.5x motor rotor inertia). 4. Confirm peak operational torque remains below 80% transient ratings.
4. Primary Panasonic MINAS A6 Tuning Parameters
| Parameter | Functional Name | Typical Setting | Tuning Guidance |
|---|---|---|---|
| Pr0.04 | Inertia Ratio | 100 - 500% | Under-estimation yields sluggish following; over-estimation induces severe motor chattering. |
| Pr1.00 | Position Loop Gain 1 | 32.0 - 50.0 /s | Governs positional stiffness and settling time; higher values accelerate arrival. |
| Pr1.01 | Velocity Loop Gain 1 | 18.0 - 30.0 Hz | Speed response bandwidth; must be balanced symmetrically against Position Gain. |
| Pr2.00 | Adaptive Filter Mode | 1 (Active) | <strong>Automatically detects mechanical resonant spikes and deploys active Notch Filters to instantly silence squeals.</strong> |
Torque Clamping via Parameter Pr0.13
In press-fitting or part clamping sequences, configure Pr0.13 (1st Torque Limit) clamped to 50% - 70% peak continuous rating. This prevents the motor from fruitlessly drawing continuous saturation current when arresting against workpieces, preventing Err 16.0 trips.