That the PC quits work indicates that there is a serious interference problem. You can cure this for the moment and only for the PC when using an UPS. But the interefence still exists and can make other devices crash another day.

You are right, using an UPS for the PC is always a good (but expensive) idea, when handling dangerous machines like big motors, etc., but I recommend to also cure this interference problem. Proper motor filters do a beautiful job...

Remember, if a person is hurted, or worse, because this interference caused any malfunction, then this is your responsibility! In Europe no device must be used which wasn't ultimatively tested on all sorts of interference (CE compatibility). Only devices must be introduced which succesfully passed these tests. Why? To ensure, that no cardiac pacemaker is malfunctioning due to this interference and no airoplane is dropping from the sky, etc. Here, engineers using non CE tested equipement being responsible for hurting or killing people have to go to jail...

If you want, we can help you to find the cause of interference.

Good luck,

Kai