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"Allen Bradley 1395 dc drive"

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alanc5 - (23 posts) Mar-25-02, 03:23 PM (EST)

"Allen Bradley 1395 dc drive"

Any Advice. I have a 1395 15 hp dc drive running a 15hp motor, which is turning a conveyor.A mat of wood get's positioned on the center of the conv.( the conv. stops by losing the last prox on the previous conv. the brake engages via air solenoid.) The brake only engages for 2 seconds and then releases. As soon as the conv. is completely stopped, 2 hold downs come down to hold the mat in pos. Then 2 saws come across cutting each end of the mat. When the saws are fully back the hold downs come up and the conv. runs the mat on down the line. THE PROBLEM IS THIS: the conv.,(WHILE THE MAT IS BEING CUT)is surging forward 1 to 2 inches. As if the drive is bumping it forward. keep in mind that the brake has already been released by the time the mat starts to get cut,(to me the brake should stay engaged until the drive command is picked back up, but someone else wrote this logic years ago).The drive command is not being picked back up until the saws are fully back and the hold downs are fully up. The presets in the drive look ok while the drive is running( A&C to stop and B to enable). The AB rep. gave me some numbers to play with. The same numbers he gave me last time about a year ago, for a totally diff. problem...???(perameters 734,735,736 for ki and kp arm. loop). hope this is enough. Any suggestions would be appreciated.....

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Table of contents

RE: Allen Bradley 1395 dc drive, rsdoran, Mar-25-02, (1)
RE: Allen Bradley 1395 dc drive, Steve Bailey, Mar-25-02, (2)
RE: Allen Bradley 1395 dc drive, alanc5, Mar-25-02, (3)
RE: Allen Bradley 1395 dc drive, rsdoran, Mar-25-02, (4)
RE: Allen Bradley 1395 dc drive, Steve Bailey, Mar-25-02, (5)
RE: Allen Bradley 1395 dc drive, Jerry Desaulniers, Mar-26-02, (6)
RE: Allen Bradley 1395 dc drive, alanc5, Mar-26-02, (7)

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rsdoran - (574 posts) Mar-25-02, 05:46 PM (EST)

1. "RE: Allen Bradley 1395 dc drive"

There are several ways to approach this, but the simplest I think would be to determine the time involved for the cut and make the brake (air solenoid) hold longer...ie the cut takes approximately 10 secs then set the brake to hold for that time or just under, make sure as long as brake is engaged drive can NOT engage.
Since the conveyor is moving but the drive is suppose to be stopped can the saw action vibration be causing the movement?
You didnt mention what options you have on the 1395..ie braking, encoders etc so its hard to determine exactly what you need. Maybe you can set the DC Hold function (a braking option) (if it isnt using an encoder) to maintain its position.
I am familiar with the 1396 so went and looked at the manual at AB site:http://www.ab.com/manuals/dr/1395/1395-5.40.pdf
Geez, another 300 page manual.

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Steve Bailey - (104 posts) Mar-25-02, 06:31 PM (EST)

2. "RE: Allen Bradley 1395 dc drive"

Has this system been working properly and just recently started acting up?
Is the mat being held in position by the holddown mechanism and the conveyor skidding along beneath it? If so, the motor current should be fairly high while the conveyor is moving. Is this the case?
Is it possible that the saw traverse mechanism is out of line and the action of the saw is dragging the mat and the conveyor downstream?
Sorry to be asking more questions than offering answers, but maybe one of the questions will help steer you in the direction of the correct solution.

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alanc5 - (23 posts) Mar-25-02, 07:06 PM (EST)

3. "RE: Allen Bradley 1395 dc drive"

sorry , Guess I should have included some more info..This system is using a dynapar encoder. Which i'm not crazy about. Yes the conv. is sliding under the mat.while the hold downs are down the saws that are cutting have a blower suctioning the excess mat away. At first I thought this was pulling the conv. I let the conv. coast into pos. without the brake engaging ,let the hold downs come down and saws come across. And to my astonishment the conv. did not budge at all. I don't know for sure because seeing is believing, but the line supervisors tell me this problem started about 2 or 3 months ago. I'm sure I can engage the brake longer until the run command is picked back up, But something is going on here, I just can't put my finger on it. One other concern is if I do engage the brake longer to try solve the problem what long term affects will this have on the drive , drive train , and gearbox??? thanks again alan..

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rsdoran - (574 posts) Mar-25-02, 07:23 PM (EST)

4. "RE: Allen Bradley 1395 dc drive"

I do not like Dynapar, BEI has been more reliable for us:
http://www.bei-encoder.com/
Thats the first thing to determine, WHY its moving. Is the drive making it move? Vibration? What happened 2 to 3 months ago, is that when you made changes to the drive?
Setting the brake longer wont matter as long as the drive is not engaged at same time. Brake is a Brake, the wear comes when you engage it not from holding (as long as the drive is stopped and there is no pressure/force acting against it when holding). Think about your cars brakes, when stopping they apply force against the drum or disc which causes friction, this creates wear. Sitting stopped at a red light (darn traffic light gets into everything) doesnt create wear because there is no motion to create friction.
BUT best to determine the WHY.

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Steve Bailey - (104 posts) Mar-25-02, 07:23 PM (EST)

5. "RE: Allen Bradley 1395 dc drive"

Is there anything in the brake mechanism that could be causing the motor to turn as the brake is releasing? If you manually shifted the air solenoid for the brake to the release position, and let the control system operate as it normally does, and the conveyor didn't drift, it's probably a mechanical, rather than a control problem
One other concern is if I do engage the brake longer to try solve the problem what long term affects will this have on the drive , drive train , and gearbox??? thanks again alan..
The conveyor sliding under the mat as it's being cut is putting a substantial side load on the saw blade and guide mechanism with attendant long-term effects.

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Jerry Desaulniers - (83 posts) Mar-26-02, 12:30 PM (EST)

6. "RE: Allen Bradley 1395 dc drive"

Maybe as the conveyor(belt I assume) is becoming worn it is producing more friction. If this is a belt that would make sense. If it is another type of conveyor maybe there is a mechanical change, look at it, think about it. Another option could be to stop the conveyor during cutting.

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alanc5 - (23 posts) Mar-26-02, 02:36 PM (EST)

7. "RE: Allen Bradley 1395 dc drive"

OK, Thanks for all the Help. After watching the process over and over I was sure that the Saws were pushing or pulling during their cuts. After going through The drive parameters We decided to lower the decel time from 1.2 to .8. Well I'm glad to say the problem is gone . I dont believe our accel time is quite as fast as is was but, I can live with that. thanks for all the help...

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alanc5 - (23 posts)	Mar-25-02, 03:23 PM (EST)
"Allen Bradley 1395 dc drive"
Any Advice. I have a 1395 15 hp dc drive running a 15hp motor, which is turning a conveyor.A mat of wood get's positioned on the center of the conv.( the conv. stops by losing the last prox on the previous conv. the brake engages via air solenoid.) The brake only engages for 2 seconds and then releases. As soon as the conv. is completely stopped, 2 hold downs come down to hold the mat in pos. Then 2 saws come across cutting each end of the mat. When the saws are fully back the hold downs come up and the conv. runs the mat on down the line. THE PROBLEM IS THIS: the conv.,(WHILE THE MAT IS BEING CUT)is surging forward 1 to 2 inches. As if the drive is bumping it forward. keep in mind that the brake has already been released by the time the mat starts to get cut,(to me the brake should stay engaged until the drive command is picked back up, but someone else wrote this logic years ago).The drive command is not being picked back up until the saws are fully back and the hold downs are fully up. The presets in the drive look ok while the drive is running( A&C to stop and B to enable). The AB rep. gave me some numbers to play with. The same numbers he gave me last time about a year ago, for a totally diff. problem...???(perameters 734,735,736 for ki and kp arm. loop). hope this is enough. Any suggestions would be appreciated.....
	Top

rsdoran - (574 posts)	Mar-25-02, 05:46 PM (EST)
1. "RE: Allen Bradley 1395 dc drive"
There are several ways to approach this, but the simplest I think would be to determine the time involved for the cut and make the brake (air solenoid) hold longer...ie the cut takes approximately 10 secs then set the brake to hold for that time or just under, make sure as long as brake is engaged drive can NOT engage. Since the conveyor is moving but the drive is suppose to be stopped can the saw action vibration be causing the movement? You didnt mention what options you have on the 1395..ie braking, encoders etc so its hard to determine exactly what you need. Maybe you can set the DC Hold function (a braking option) (if it isnt using an encoder) to maintain its position. I am familiar with the 1396 so went and looked at the manual at AB site:http://www.ab.com/manuals/dr/1395/1395-5.40.pdf Geez, another 300 page manual.
	Top

Steve Bailey - (104 posts)	Mar-25-02, 06:31 PM (EST)
2. "RE: Allen Bradley 1395 dc drive"
Has this system been working properly and just recently started acting up? Is the mat being held in position by the holddown mechanism and the conveyor skidding along beneath it? If so, the motor current should be fairly high while the conveyor is moving. Is this the case? Is it possible that the saw traverse mechanism is out of line and the action of the saw is dragging the mat and the conveyor downstream? Sorry to be asking more questions than offering answers, but maybe one of the questions will help steer you in the direction of the correct solution.
	Top


	alanc5 - (23 posts)	Mar-25-02, 07:06 PM (EST)
	3. "RE: Allen Bradley 1395 dc drive"
	sorry , Guess I should have included some more info..This system is using a dynapar encoder. Which i'm not crazy about. Yes the conv. is sliding under the mat.while the hold downs are down the saws that are cutting have a blower suctioning the excess mat away. At first I thought this was pulling the conv. I let the conv. coast into pos. without the brake engaging ,let the hold downs come down and saws come across. And to my astonishment the conv. did not budge at all. I don't know for sure because seeing is believing, but the line supervisors tell me this problem started about 2 or 3 months ago. I'm sure I can engage the brake longer until the run command is picked back up, But something is going on here, I just can't put my finger on it. One other concern is if I do engage the brake longer to try solve the problem what long term affects will this have on the drive , drive train , and gearbox??? thanks again alan..
		Top


	rsdoran - (574 posts)	Mar-25-02, 07:23 PM (EST)
	4. "RE: Allen Bradley 1395 dc drive"
	I do not like Dynapar, BEI has been more reliable for us: http://www.bei-encoder.com/ Thats the first thing to determine, WHY its moving. Is the drive making it move? Vibration? What happened 2 to 3 months ago, is that when you made changes to the drive? Setting the brake longer wont matter as long as the drive is not engaged at same time. Brake is a Brake, the wear comes when you engage it not from holding (as long as the drive is stopped and there is no pressure/force acting against it when holding). Think about your cars brakes, when stopping they apply force against the drum or disc which causes friction, this creates wear. Sitting stopped at a red light (darn traffic light gets into everything) doesnt create wear because there is no motion to create friction. BUT best to determine the WHY.
		Top


	Steve Bailey - (104 posts)	Mar-25-02, 07:23 PM (EST)
	5. "RE: Allen Bradley 1395 dc drive"
	Is there anything in the brake mechanism that could be causing the motor to turn as the brake is releasing? If you manually shifted the air solenoid for the brake to the release position, and let the control system operate as it normally does, and the conveyor didn't drift, it's probably a mechanical, rather than a control problem One other concern is if I do engage the brake longer to try solve the problem what long term affects will this have on the drive , drive train , and gearbox??? thanks again alan.. The conveyor sliding under the mat as it's being cut is putting a substantial side load on the saw blade and guide mechanism with attendant long-term effects.
		Top


	Jerry Desaulniers - (83 posts)	Mar-26-02, 12:30 PM (EST)
	6. "RE: Allen Bradley 1395 dc drive"
	Maybe as the conveyor(belt I assume) is becoming worn it is producing more friction. If this is a belt that would make sense. If it is another type of conveyor maybe there is a mechanical change, look at it, think about it. Another option could be to stop the conveyor during cutting.
		Top


	alanc5 - (23 posts)	Mar-26-02, 02:36 PM (EST)
	7. "RE: Allen Bradley 1395 dc drive"
	OK, Thanks for all the Help. After watching the process over and over I was sure that the Saws were pushing or pulling during their cuts. After going through The drive parameters We decided to lower the decel time from 1.2 to .8. Well I'm glad to say the problem is gone . I dont believe our accel time is quite as fast as is was but, I can live with that. thanks for all the help...
		Top

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