Gettys servo data help needed

[chuckw97055]

I have a Cincinnati 10VC-1250 I'm embarking on a retro fit with and I'm gathering all the data on it I can.
The servos are Gettys but the data plates are a bit cryptic... I could use some help decoding them-

Type- 16-0375-05
Serial #-4612-330
DataSheet- 201-113-2024
Connection Diag- 201-133-2024
Outline dwg- 201-233-2121
(unlabeled field)- 36491S-19
8-brushes
Resolver feedback

The drives are Acradrive P-55 (SCR, 240 volt, 35 amp, single phase)

Thanks!

[Al_The_Man]

Unfortunately those numbers do not tell much, you don't really need to know if you are using the same motors AND drives.
If you are changing the drives, then you may have to find out the specs by doing some tests.
Many of the motors on the older Cincinnati's were pretty big, as Getty's usually were.
If the resolvers went back to the control, you may have to switch them to encoders to be compatible with most systems.
You are lucky the drives are single phase, many were 3 phase.
Al.

[chuckw97055]

I am planning on updating the drives and switching to encoders.

Can you list the tests you'd recommend doing on those servos to find the relevant data?

[Al_The_Man]

This is one method that may help, but in your case you may not need to go to that trouble if you use the rating of the existing drives, i.e. 240v PWM drive at 35amps.
What kind of system are you thinking of using? step/direction control or Analogue?
BTW, if the motors have tach's, you can eliminate these with modern torque mode drives.
Al.

[chuckw97055]

Thanks for the test info. That gives me something to go on.

Can you see any reason to not trust the existing amps ratings (240V, 35amp, scr) as an indicator of the servos ratings? For example, is the SCR drive going to be limited to 190V rectified? Could the Acradrives have current limiting? These kinds of issues are what made me want the Gettys specs.

I'm still gathering information and I don't know what kind of amps I'll end up with (step/dir, analogue, pwm/dir). I'd love to hear any and all ideas about what kind of amp setup would be best (affordable 1st, rugged 2nd). Is there a $500 modern drive out there suitable for these servos? Can someone build some for me?
I'm not opposed to keeping the Acradrives ultimately, but the service options I've seen out there suggests they are going to be too expensive to support.

[Al_The_Man]

SCR drives are pretty rugged, and been around a long time.
If I have to, I have replaced them with A-M-C PWM drives, but most, especially the DC drives do not have step/dir, only analogue.
The system you are using will pretty much decide what type you can use.
Al.

[chuckw97055]

I found the 50A20DD drive (190V, 25A cont) http://www.servosystems.com/amc_50a8dd.pdf
and submitted a request for quote... any idea what they go for?
Thanks,
Chuck

[Al_The_Man]

I have an older Cat/price list and show the 50A8DD & 50A20DD AS $520.00
The 50A8 is restricted to 80v max, the 50A20 to 190vdc.
You will need a large common DC power supply for these units.
I usually buy direct from AMC.
Al.

[chuckw97055]

I wrote a few e-mails to servo repair shops and Ray from Electric Enterprise wrote back with the info I needed. He put in a request to the Gettys Eng. Dept. and the results were:

(See beginning of thread for motor application and data plate)

Back EMF- 79.5 V per 1000 rpm
Max RPM- 2000
Max V- 160
33 Amps
222 in lbs torque


Thanks Ray and Al!
Chuck