brake voltage on fanuc red caps

[Montabelli]

I have seen posts indicating that the fanuc ac servo brakes are 24 volt and also seen posts indicating they are 110 volt. I have an old motion master I am working on, it has fanuc model 5 110v ac servos I tried 24v dc to release the brake and it didn't seem to do any thing could someone please tell me what the brake voltage is on these motors?

[Al_The_Man]

There seems to be differing information of this, I have the Fanuc servo manuals and it does not seem to indicate definitively what it is.
For the AC red cap motors I have with a brake I did several tests, on the motors I have they measure 300 ohm, AC did not pull the brake in at all, using a variable DC supply the brake would pull in around 45vdc, I am assuming that these are 100vdc brakes, I am presently using them with a bridge rectifier across the 120v AC supply with no capacitor, and they operate fine.
The measured DC is 105v, and they appear to be polarity sensitive.
You should also wire a reverse EMF diode, 1N4005 across the brake.
Al.

[Andre' B]

I am not real positive but I want to say 90 VDC.

[Montabelli]

thanks guys, 110v worked no problem!

[Al_The_Man]

DC or AC?
Al.

[underthetire]

Depends on how the motor was ordered. I've seen 24VDC and 90VDC. I have yet to see an AC one, but that could just be the machines I work on. Typically, the 90VDC ones come off the 100V ac transformer to a bridge rectifier. Some brakes actually use a dual voltage set up as well.

[dpuch]

Per Fanuc 65232 manual section 8
beta series AC servo motors use 90V DC (or full wave rectified 100v AC) and a caution NOT to use half wave rectified 200V AC
Model numbers A06B-0113-B... A06B-003x-B... <-- x = 1 to 4

Same for alpha series AC servo motors per 65142 manual section 7
too many models to list