Haas 122 alarm: Regen overheat

The Haas brake resistor/regeneration circuit overheats. It is an alarm from the Power supply area, and in the catalog it is listed as “Regen overheat”. On the machine you notice it like this: Alarm when braking spindle or axes, May coincide with an overvoltage, Calor en zona de resistencias.

On the shop floor it almost always comes from one of these causes: Frenadas muy agresivas, Vector drive/regeneration defective, Insufficient ventilation, Damaged resistance. Rule out the most likely one on your machine first, before touching parameters or swapping anything.

Reset after cooling and cause review. Resetting without fixing the cause first only hides the problem: Haas 122 trips again and, in the meantime, you keep working with the machine in bad shape.

With the machine stopped and in a safe state, start with these checks: Note when it occurs, Let it cool down, Do not touch hot resistors or the energised cabinet. That alone will tell you whether it is the program or whether you need to raise a maintenance job.

With Haas 122 active, avoid this: Do not bypass safety devices, Do not manipulate energized electrical cabinet, Do not continue producing if the alarm reappears. Skipping any of these points is what turns a minor stop into an expensive breakdown.

If it appears again after cooling or next to vector drive alarms. If you are not sure how far it goes, stop the machine and report it: a repeat alarm always works out cheaper than a crash.

It is critical: there is a real risk of damage to the machine, the tool or a person. Leave the machine stopped, do not keep resetting it to see if it goes away, and call maintenance before producing again. Guidance reference. Always confirm the full text in the exact machine/control manual.