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Old October 19th, 2014, 12:22 AM   #1
unsaint32
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powerflex 525. Using the Relay 1 contact (R1 & R2) to apply/release brake.

I want to use the relay 1 terminals (R1 & R2) to energize an external relay that powers a brake solenoid. In other words, I want the relay 1 to be energized so that the R1 & R2 contact gets closed when the drive is energized but no moition command is given to the drive. Is that a default condition of how the relay 1 works, or do I have to configure the drive to make the relay 1 work like that? If I have to configure that, can you tell me how I can do that? I combed through the manual but cannot find it. Thanks.
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Old October 19th, 2014, 12:54 AM   #2
bob1371
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Here is the Manual, page 87 shows the options to set parameter t076. This will tell relay 1 how to act.

it's default is 0 which I believe is what your looking for.
0 “Ready/Fault” Relay changes state when power is applied. Indicates that the drive is ready for operation. Relay returns drive to shelf state when power is removed or a fault occurs.
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Old October 19th, 2014, 04:38 AM   #3
unsaint32
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The description of the default selection reads
"Relay changes state when power is applied. Indicates that the drive is ready for operation."

I don't know if I can use that because I need the relay 1 output to be off again (the contact position returns to the normally open position in order to release the brake) when the drive is commanded to run.

Thanks Bob1371.
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Old October 19th, 2014, 04:46 AM   #4
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Quote:
Originally Posted by unsaint32 View Post
The description of the default selection reads
"Relay changes state when power is applied. Indicates that the drive is ready for operation."

I don't know if I can use that because I need the relay 1 output to be off again (the contact position returns to the normally open position in order to release the brake) when the drive is commanded to run.

Thanks Bob1371.
Ok, I misread your original post. I have always dealt with brakes that had to be powered in order to release.

There are 25 or so possible settings for that parameter, you might find one that works for you.
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Old October 19th, 2014, 08:19 PM   #5
unsaint32
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We tried the selection #15 - EM Brk Cntrl, and it worked exactly how I wanted. We even fine tuned it with on and off delay from parameter 86 & 87.

Thanks.
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Old October 20th, 2014, 08:05 AM   #6
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Good deal....
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Old October 20th, 2014, 11:19 AM   #7
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Word to the wise: use the relay contact to power a plug-in interposing relay, then use THAT relay's contacts to power the brake release coil. Eventually the contacts will burn on that relay, the inductive coil load is hard on them. It's easier to plug in a new ice cube relay than to replace the control core on the 525.
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Old October 25th, 2014, 02:09 AM   #8
unsaint32
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Quote:
Originally Posted by jraef View Post
Word to the wise: use the relay contact to power a plug-in interposing relay, then use THAT relay's contacts to power the brake release coil. Eventually the contacts will burn on that relay, the inductive coil load is hard on them. It's easier to plug in a new ice cube relay than to replace the control core on the 525.
Yes, that is actually what we ended up doing, just based on previous experiences. I didn't know about the inductive load being hard on the contact though. Thanks.
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Old February 6th, 2020, 07:17 PM   #9
alexbeatle
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Hello!
Though this is an older post, I've got a similar application.

I'm using PF525 with motor+brake controlled by a relay1. It's used on the lift with a counterweight. I set it up per https://rockwellautomation.custhelp....il/a_id/587578
t086 and t087 = (default) 2s.

But when I Stop, the lift slips before stopping. I'm assuming it's because of the counterweight and the brake isn't holding it quick enought!?

Visually, the sequence of events is
1. Stop command
2. Lift drops aprox. 2 inch.
3. Brake clicks (engaged)
4. Lift stops

Any suggestions, please?
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Old February 11th, 2020, 01:37 PM   #10
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bump
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Old February 11th, 2020, 03:31 PM   #11
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I did an elevator application like yours before and the tuning is very important. The drive is supposed to hold the rotor in a fixed state at 0hz for those two seconds. Also had to manually tune it ... adjusted a couple parameters to make this work. Don’t shorten the 2seconds as it is supposed to measure and re energize if there is movement before applying the brake and catch this issue that you’re having. Maybe try p043 to the 0.1hz and see if this extra juice helps...?
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Old February 11th, 2020, 06:43 PM   #12
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Quote:
Originally Posted by jholm90 View Post
I did an elevator application like yours before and the tuning is very important. The drive is supposed to hold the rotor in a fixed state at 0hz for those two seconds. Also had to manually tune it ... adjusted a couple parameters to make this work. Don’t shorten the 2seconds as it is supposed to measure and re energize if there is movement before applying the brake and catch this issue that you’re having. Maybe try p043 to the 0.1hz and see if this extra juice helps...?
What you are describing is called "Torque Proving" and the PF525 is not capable of that, it does no offer true Torque Control mode. You need a PF7xx class drive for that.
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Old February 11th, 2020, 06:57 PM   #13
alexbeatle
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Quote:
Originally Posted by jraef View Post
What you are describing is called "Torque Proving" and the PF525 is not capable of that, it does no offer true Torque Control mode. You need a PF7xx class drive for that.
I have other lifts and they are ran by PF525 no problem. They do use DC brake, thinking of using the same.

The lifts I have elsewhere are setup as:
p45 - DC Brake, CF
p76 - MotorRunning (Motor Brake via external contactor)
p434 - 1s
p435 - 2A
p437 - NoProtection

Quote:
Originally Posted by jholm90 View Post
I did an elevator application like yours before and the tuning is very important. The drive is supposed to hold the rotor in a fixed state at 0hz for those two seconds. Also had to manually tune it ... adjusted a couple parameters to make this work. Don’t shorten the 2seconds as it is supposed to measure and re energize if there is movement before applying the brake and catch this issue that you’re having. Maybe try p043 to the 0.1hz and see if this extra juice helps...?
Would this make the motor always on?
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Old February 11th, 2020, 06:58 PM   #14
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Quote:
Originally Posted by jraef View Post
What you are describing is called "Torque Proving" and the PF525 is not capable of that, it does no offer true Torque Control mode. You need a PF7xx class drive for that.
Assuming it's PF7xx, any particular params to control the brake action quicker?
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Old February 11th, 2020, 08:58 PM   #15
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This may not be an issue with the drive. This could be an issue with the brake rectifier on the motor. For vertical lifting applications you need a fast acting brake. Not just a standard brake setup.

For SEW motors this is accomplished with an SR or UR relay. In your case the UR relay would apply with the use of a VFD.
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