MT30M4-28 Servo Motor Specs?

[Lasershop]

Bridgeport V2XT. SEM MT30M4-28 servo motors. My Servo Dynamics amp instructions wants to know what the "continuous current rating" is for initial setup. I have looked and searched. Anybody know?

[Sparky_NY]

My v2e3 has powertron servos. I believe they are pretty much the same beast just a different vendor. The powertron motors are 15.6 amps continuous, 58amps peak pulse.

[Lasershop]

Originally Posted by Sparky_NY My v2e3 has powertron servos. I believe they are pretty much the same beast just a different vendor. The powertron motors are 15.6 amps continuous, 58amps peak pulse.

Thanks for the info. Here is what the label on the motors read exactly:

SEM
TYPE MT30M4-28 NO. G30450
C: STALL: TORQUE 26 LB/IN A
MAX: 4000 RPM 112 V 65 A
TACHO 7 V/KRPM IP 44 IC 40
B-T 31542060 B90-92853
FERRITE BRUSHED SERVOMOTOR

[Sparky_NY]

Originally Posted by Lasershop Thanks for the info. Here is what the label on the motors read exactly: SEM TYPE MT30M4-28 NO. G30450 C: STALL: TORQUE 26 LB/IN A MAX: 4000 RPM 112 V 65 A TACHO 7 V/KRPM IP 44 IC 40 B-T 31542060 B90-92853 FERRITE BRUSHED SERVOMOTOR

I can help you break that down a bit.

My motors are 30lb torque, 6000 rpm max and 146 volt max so slightly different.

On yours, the 26lb torque is a continous rating. The peak torque is determined by the max peak current rating, IP44A in your case. That 44A rating is where the permenent magnets in the motor will be damaged if that current is exceeded, so stay a fair margin away from that. I believe the IC40 rating is the max continous current rating, I being the symbol for amps, C for continous. That seems high however, my motors are 15.6 cont. rated. The servo drive itself limits the continous current to the value you enter but normally allows higher currents for very short peroids (like accelerating from a stop). Different drives handle these things differently. I would start with the current set to 15 amps and then increase it keeping a eye on the motor temperatures. The motors can run quite warm, that is normal. Current is what determines torque in a servo motor. Higher currents will give you faster acceleration and as a result, lower encoder following errors during acceleration. I ended up running mine at 20 amps, the drive allows 40 amp short peaks, the motors never get more than slightly warm.

The 40amp IC rating on your motor seems high for a bridgeport. My original bridgeport servo drives were 15amp continous and allowed 30 amp peaks. The fuse for each axis was 25amps slow blow which also gives a good hint of the current used by the motors.

Although your motors are rated for a max of 4000 rpm (mine are 6000) they operate well below that. With a 5 TPI ballscrew and a 2:1 belt drive, 250IPM rapids is only 2500rpm at the motor. Voltage determines RPM with a servo motor. I would expect your power supply is slightly under 100 volts.

The Tach puts out 7 volts for each 1000 rpm from your tag. Most aftermarket servo drives do not use the tach output. I removed the brushes from my motor for the tach.

Hope this helps some.

[Lasershop]

Originally Posted by Sparky_NY I can help you break that down a bit. My motors are 30lb torque, 6000 rpm max and 146 volt max so slightly different. On yours, the 26lb torque is a continous rating. The peak torque is determined by the max peak current rating, IP44A in your case. That 44A rating is where the permenent magnets in the motor will be damaged if that current is exceeded, so stay a fair margin away from that. I believe the IC40 rating is the max continous current rating, I being the symbol for amps, C for continous. That seems high however, my motors are 15.6 cont. rated. The servo drive itself limits the continous current to the value you enter but normally allows higher currents for very short peroids (like accelerating from a stop). Different drives handle these things differently. I would start with the current set to 15 amps and then increase it keeping a eye on the motor temperatures. The motors can run quite warm, that is normal. Current is what determines torque in a servo motor. Higher currents will give you faster acceleration and as a result, lower encoder following errors during acceleration. I ended up running mine at 20 amps, the drive allows 40 amp short peaks, the motors never get more than slightly warm. The 40amp IC rating on your motor seems high for a bridgeport. My original bridgeport servo drives were 15amp continous and allowed 30 amp peaks. The fuse for each axis was 25amps slow blow which also gives a good hint of the current used by the motors. Although your motors are rated for a max of 4000 rpm (mine are 6000) they operate well below that. With a 5 TPI ballscrew and a 2:1 belt drive, 250IPM rapids is only 2500rpm at the motor. Voltage determines RPM with a servo motor. I would expect your power supply is slightly under 100 volts. The Tach puts out 7 volts for each 1000 rpm from your tag. Most aftermarket servo drives do not use the tach output. I removed the brushes from my motor for the tach. Hope this helps some.

Thank you for all the info. The Servo Dynamics amps I have need to be bench setup for torque mode and set to the motor size. According to the instructions the motor pot settings are all the same from 10 amps and up so it sounds like I am safe. I am setting it up for torque mode. I tried the velocity mode but I just couldn’t get it figured out correctly. I can at least get it to function in torque mode. Is removing the tach brushes necessary?

RonO

[Al_The_Man]

When setting up for velocity mode in a closed loop system, you usually have to tune the Tach loop first without the controller loop closed.
Torque is usually the better bet.
As a general rule, you can turn the amp gain to max and the tach gain to minimum in torque mode, if the drive is tuned by trim pots.
I also take the tach brushes out just to remove unnecessary components.
Al.

[cncsnw]

SEM TYPE MT30M4-28 NO. G30450 C: STALL: TORQUE 26 LB/IN A MAX: 4000 RPM 112 V 65 A TACHO 7 V/KRPM IP 44 IC 40 B-T 31542060 B90-92853 FERRITE BRUSHED SERVOMOTOR

I am pretty sure "IP44" relates to environmental protection ("ingress protection"). It rates how well the enclosure (motor case) keeps out particulates and fluids. I think "IC" is a related environmental rating, but am not sure what it stands for.

The "MAX: ... 65A" line specifies that the peak allowable current is 65A.

I would guess that the "A" at the end of the "C: STALL:" line (giving continuous stall ratings) could/should have been followed by an amp value that would correspond to the 26 in-lb continuous torque. That value would probably be in the 12-20A range, similar to Sparky_NY's motors at 15.6A.

A motor in this size and application would certainly not have a 40A continuous current rating.

[sclark58]

Hi Everyone; I was told I needed to post here due to fact that someone was looking for service for their motor,