Pacific Scientific R33

[golfietis]

I have got 2 Pacsci servo motors. They are R33 motors. Unfortunately I was not able to find out what type of encoder they have. I have emailed Pacsci support, unfortunately have got no answer...

Motors model number is R33SSNC-SS-NS-NC-02.

I understand that they have no secondary feedback device, no shaft seal. But feedback device "SS" is not in the documentation provided by pacsci.

Also they say:

R30 Series Motor - 3.25" width/height (square frame) 4-pole synchronous servomotors Samarium-cobalt permanent magnets for maximum torque-to-inertia without demagnetization Low rotor inertia for rapid accel/decel 240V ac, 320V dc bus operation Anti-cog stator design Rated speeds to 7,000 RPM

What does this 240 AC and 320V DC means? Can I connect it to AC or DC driver?

[Matt Adams]

I work for a PacSci distributor. From the part number, this is a brushless DC motor that was custom for an OEM.

Since it doesn't have standard feedback (resolver), i wouldn't be surprised if it had Sine Encoder feedback.

240 volts AC through a rectifier yields 325 VDC. This motor can handle a servo drive whose voltage is either up to 240 VAC.

Good luck,

Matt

[Al_The_Man]

It appears from the data I have that the primary feedback only is a 8 pin connector that would be a Tachsyn, Resolver or Hall sensors.
You most likely could tell by resistance check, if fairly low resistance from A-C (cosine) and same from B-D (sine), then this should be the result for the resolver, if a reading between C-D-E is the same then it could be a Tachsyn, the Hall effect is A+ve B-ve C D E is H1,H2,H3
If a 17 pin connector then there will also be encoder output. The pin out is the same pin letter for the commutation..
Al.

[golfietis]

Thanks guys for answers....

I will take picture of the connectors and feedback device tomorow. When I looked at it, it (feedback device) looked similar to RC brushless motor...

Also, what type of pacsci drive should I look for these motors? Documentation looks quite confusing for me...

Or I might look at Granite Devices drives... But they are 160 VDC only...

[Matt Adams]

The first step is to find the feedback type. There are only a few drives out there that can handle a wide variety of feedback devices within a single part number. You'll be really sad if you buy a drive that can only handle incremental encoder feedback with halls and you're stuck with a resolver or sine encoder!

Matt

[Al_The_Man]

The type of feedback decide the nature of the drive required, BLDC, AC sinusoidal etc.
Also depends on what is the nature of the control signal, analogue, step/dir etc.
Al.

[golfietis]

Some photos of my motors

[Al_The_Man]

Well it looks like you do not have an encoder, either a Tachsyn or resolver, I suspect the latter by the look of it, the drives that use these typically are AC sinusoidal and extrapolate and encoder signal from the Resolver phases.
You either need a drive that is compatible with this particular resolver or fit an encoder with hall tracks for a four pole motor.
Al.

[golfietis]

Thanks Al

Looks like I will need encoders. This will be best way..