[autotechsteve]

Well I am almost done with the rebuild on my VF-1. I went out to the shop today with the intentions of loading the program, setting up the stock and giving it a dry run. After powering it up, homing it and a few movements I noticed the characteristic electrical burning smell. I quickly shut it down and open the rear door only to have smoke come billowing out at me! After the smoke clears I get a chance to see what happened. Apparently the two spindle brake resistors got red hot and started to burn everything near to themselves. The servo resistor in between the two did not get hot. I let it cool off and powered it up again. The resistors immediately start to heat up. I shut it down again. I noticed that the drive had an error code E6E on the display, "Brake transistor fault detection." As far as I can tell, only the resistors are ruined and some wiring, so far. The wire looms are shot in a few places but they will serve their purpose "as is" for now. I Googled the drive and problem but came up with nothing.

Here is the information that I have gathered so far to try and diagnose what happened. The only work I have recently done to the mill was I put a rectifier bridge in to convert to AC voltage for the light to DC to run my new LED lights. If I unplug the LED and the rectifier the resistors still get hot at start up so I don't think that caused it, I hope. After I powered it up I homed it, moved it back to center of its travels, then homed it again. The auto power up is slow to home but the second time I homed it was at rapids. I think this may have been the point that something failed but I don't know. Also I got no over-temp alarms even thought the temp sensors got so hot they melted! The drive lists an input of 230v at 60 hz on the front panel. I am getting 244, 243, 242 from my phase converter while loaded. I am dead on 60 Hz as well. The drive is a Mitsubishi Freqrol-Z300 model# FR-Z320-3.7K.

I am so close to making parts that this makes me sick to my stomach!
Anyone out there have any advise?

Steve

PS. I am so ticked about this I have managed to consume 3 beers while writing this, benefits of a home shop and being able to call it a day whenever.

[underthetire]

Sounds like the brake transistor module failed dumping all the current to the resistors.

[autotechsteve]

Some how two identical threads were started so to resolve any confusion, this is not the main thread, this is.
http://www.cnczone.com/forums/haas_m...ught_fire.html

Steve