Scope of this technical record
Defines the Unidrive evidence package for braking, Over Volts, O.ht and thermal/cooling cases.
Brake resistors and heatsinks can be hot; DC-bus discharge must be verified before access.
Unidrive braking/thermal evidence route
The evidence record connects Over Volts and O.ht to application and hardware boundaries.
Unidrive braking thermal evidence image
Evidence package
The record should show load type, stop/decel profile, brake resistor and wiring, chopper evidence, cooling fan/heatsink state, ambient conditions and whether the trip is cold or hot-load related.
- Load and stop profile
- Brake resistor value/wiring
- Brake chopper evidence
- Fan and heatsink condition
- Cold/hot trip timing
Repair boundary
A braking/thermal case moves to board repair only after load, resistor, chopper, fan and heatsink evidence is reconciled. Otherwise the first action may be application or cooling correction, not electronics replacement.
Field record checklist
- Load energy
- Brake hardware
- Chopper evidence
- Cooling evidence
- Thermal timing
Technical basis and reference documents
This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.
Public trip-code context for Over Volts and thermal events.
Linked circuit records
Routes Over Volts evidence through line voltage, DC bus, load regeneration, deceleration ramp, brake resistor, brake chopper and feedback-induced instability.
Routes PS.24V, thermal feedback and encoder instability through external 24 V loads, option modules, feedback wiring, sensor supply, heatsink feedback and control-board evidence.
Turn this record into a qualified service request
A repair decision is much more reliable when the request includes the exact identity of the drive, the first fault evidence and the machine condition when the symptom appeared.
- Complete drive type code / MLFB or nameplate model
- Fault code, fault value and first event before reset
- When the event appears: power-up, enable, ramp, run, decel or stop
- Motor/cable connected or isolated during the symptom
- Visible board, option-card, module and connector identifiers
- Previous repair history, replacement parts and repeat-failure pattern