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I2t Fault when moving the motor on relatively low current
#1
Hi,

I have written a program which moves my motor for 0 mu to 30000 mu and back.
Nothing else is happening, but when I keep it on for approximately 1-2 minutes, it gets an I2T fault.
This is what I get.

Coord[1].AmpFault=1 @ 17-9-2015 14:29:58
Coord[1].I2tFault=1 @ 17-9-2015 14:29:58
Motor[1].AmpFault=1 @ 17-9-2015 14:29:58
Motor[1].I2tFault=1 @ 17-9-2015 14:29:58

I watched the power supply when it happend and the amps were while moving about 0.1 amps and on the start of the move about 0.4 amps.
The specs of my motor are:
Continuous current: 0.5 amps
Instantaneous Current: 2 Amps
Max time allowed: 3 secs
To me it looks like it shouldn't happen. Is it something within I2t that calculates the max time it is allowed betweens continuous an max amps when it happens more often?

Maarten
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#2
In the other post about this subject Richard asked these questions.

I assume that you are referring to the firmware I2T fault. Correct?
What are the motor's continuous and peak current specifications (RMS)? Is the amp 5/15A?
What are your I2T settings? These are the PPmac structures.

Motor[x].I2tSet
Motor[x].I2tTrip
Motor[x].MaxDac

It would be helpful to get this data from you.
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#3
(09-17-2015, 07:24 AM)bradp Wrote: In the other post about this subject Richard asked these questions.

I assume that you are referring to the firmware I2T fault. Correct?
What are the motor's continuous and peak current specifications (RMS)? Is the amp 5/15A?
What are your I2T settings? These are the PPmac structures.

Motor[x].I2tSet
Motor[x].I2tTrip
Motor[x].MaxDac

It would be helpful to get this data from you.

I assume that you are referring to the firmware I2T fault. Correct?
Yes, the one in the IDE

What are the motor's continuous and peak current specifications (RMS)?
All I know are the continuous and peak current in Amps, there is no datasheet for the motor so I can't find it.

Is the amp 5/15A?
Yes, it is

What are your I2T settings? These are the PPmac structures.
Motor[x].I2tSet = 684.50446
Motor[x].I2tTrip = 21083212
Motor[x].MaxDac = 2737.9341

The Max Dac is limited to 2700 in my control loop.
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#4
It seem like the i2tSet value is rather low. What do you have for the motor continuous current and peak current values in the data base page. I would like to understand where this value came from.
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#5
(09-18-2015, 10:06 AM)bradp Wrote: It seem like the i2tSet value is rather low. What do you have for the motor continuous current and peak current values in the data base page. I would like to understand where this value came from.


The continuous current is 0.5 amps in the current unit Amp_RMS.
The instantaneous current is 2 amps in the current unit Amp_RMS.
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#6
I figured out my mistake, I did not pay attention that the unit was 5A/15A. So the numbers all make sense. That being eliminated can you monitor the value in Motor[].PhasePos and see if it ever becomes other than zero.
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#7
(09-21-2015, 03:05 AM)bradp Wrote: I figured out my mistake, I did not pay attention that the unit was 5A/15A. So the numbers all make sense. That being eliminated can you monitor the value in Motor[].PhasePos and see if it ever becomes other than zero.

Motor[1].PhasePos remains 0 the entire time.
I still get the I2tFault, and even then value doesnt change

Coord[1].AmpFault=1 @ 21-9-2015 13:35:22
Coord[1].I2tFault=1 @ 21-9-2015 13:35:22
Motor[1].AmpFault=1 @ 21-9-2015 13:35:22
Motor[1].I2tFault=1 @ 21-9-2015 13:35:22
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#8
I think I found what I did wrong.
I just checked the serial number of the Power Brick I have, and it says that I only have 1A/3A amplifier, and in the settings I filled in it was 5A/15A.
I taught it was a 5A/15A amplifier because I looked at the power brick lv user manual and it said on page 24 that an amplifier without a indicator was a 5A/15A amplifier.
I have no indicator on all of my amplifiers. I had it running for 5 minutes now without an I2t fault, so that was probably it.
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