adccommunitymod (AutomationDirect) asked a question.
Created Date: July 30,2012
Created By: doug6949
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Our electrical contractor just spent the morning with me going over our emergency stop systems. I was aware of our shortcomings and asked for a proposed solution. The contractor, an AB dealer, recommended new Safe-Off drives as a simple answer to our compliance issues. So here are my questions: 1. Does this "Safe-Off " feature eliminate the need for a safety contactor, or otherwise reduce wiring costs? 2. Do GS2 drives have an equivalent feature? I was told this is different than a simple enable pin in that it prevents firing signals to the IGBT's. Sounds fishy, but I'm not the drive expert. TNX; Doug
Created Date: July 30,2012
Created by: bcarlton
1. A 'safe-Off ' input DOES NOT relieve the need for a safety relay. It allows a safe 'no motion possible ' mode of the drive while the 3 phase power is still attached. While a failure could apply power to a motor it would not be in the rotating manner needed to cause motion.
2. The GS2 does not mention a 'safe-off ' mode. If it doesn't say it and certify it then it isn't there.
Note that the 'safe-off ' mode does not necessarily remove all power out to the motor. If any wiring or maintenance is to be done on the motor the system must be shut down or at least a safety disconnect between the drive and the motor must be switched off.
Created Date: July 30,2012
Created by: Adisharr
Motion systems are always more difficult to properly safe guard. What happens when you open the safety relays on the AB drive? Does the motor coast? Would it be better to have a controlled decel? All very application dependent.
That being said, the AB drives are one of the few with this feature properly implemented. They have two internal safety relays tied to the gate power supply and enable. You 're still going to need to use a proper safety interface to these relays.
Note that none of this takes the place of completely removing power from the drives for maintenance.
Created Date: July 30,2012
Created by: doug6949
Sounds like I wouldn't be gaining anything. A regular AB drive is twice the price of the GS2. The Safe-off feature may double that again.
Safety monitors and contactors aren't that expensive.
IEC61800-5-2 seems like a good idea. I think I'll wait for the generics to hit the shelves first.
Created Date: July 31,2012
Created by: deep6ixed
Use the external safety contactor. I never rely on a drive "feature " and always design more than one level of safety into an motion control safety system.
The AD line of safety relays have worked like a champ for us at our facility and are fully featured for much less than a Pinoz or AB system.
And as Adisharr said, designing motion control safety systems is highly application dependent. Some of our high hp (300hp+) require the drive to be powered to a stop due to excessive coasting of almost a minute, then powered off after the drive stops.
Created Date: July 31,2012
Created by: Adisharr
Use the external safety contactor. I never rely on a drive "feature " and always design more than one level of safety into an motion control safety system.
The AD line of safety relays have worked like a champ for us at our facility and are fully featured for much less than a Pinoz or AB system.
And as Adisharr said, designing motion control safety systems is highly application dependent. Some of our high hp (300hp+) require the drive to be powered to a stop due to excessive coasting of almost a minute, then powered off after the drive stops.
Around here, a 20HP drive is a big unit ;)
Created Date: July 31,2012
Created by: bcarlton
For the controlled stop applications we use a safety relay with time delayed contacts. The instantaneous contacts command the stop. The time delayed implement the 'safe-off ' or just disconnect the power contactor if there is no 'safe-off ' feature.
Created Date: August 04,2012
Created by: kewakl
--------Maybe a bit off topic, but...--------
My experience with Safe Torque Off (AB Kinetix 300 **First gen**) was very painful!
The STO input circuit would JUST QUIT FUNCTIONING! Persistent E39 code.
It was as if the optocouplers on the inputs died.
Even with the connector jumpers installed in the *bypass* mode -- nothing.
Our rep insisted that nothing was wrong with the drives.
Then our equipment supplier informed us that the first batch that they used were almost ALL failing in the field. We had three or four replaced under warranty with LESS THAN 300 hours of runtime.
So, with my jaded view of the whole Safe Torque Off concept, I would not be able to offer anything except --- the above:eek:
Created Date: January 25,2013
Created by: CFenster
--------Maybe a bit off topic, but...--------
My experience with Safe Torque Off (AB Kinetix 300 **First gen**) was very painful!
The STO input circuit would JUST QUIT FUNCTIONING! Persistent E39 code.
It was as if the optocouplers on the inputs died.
Even with the connector jumpers installed in the *bypass* mode -- nothing.
Our rep insisted that nothing was wrong with the drives.
Then our equipment supplier informed us that the first batch that they used were almost ALL failing in the field. We had three or four replaced under warranty with LESS THAN 300 hours of runtime.
So, with my jaded view of the whole Safe Torque Off concept, I would not be able to offer anything except --- the above:eek:
We 're fighting the same problem at my plant. We 've now had 3 drives go to an E39 error. One that was sent out for repair came back and failed to E39 within the first hour of operation.
Did you ever receive any details from your rep about the size of this first batch or how it's being dealt with? We 're these failures covered under warranty? Any information you can provide would be helpful.
Thanks
Created Date: January 25,2013
Created by: kewakl
We 're fighting the same problem at my plant. We 've now had 3 drives go to an E39 error. I thought that I got all of the bad ones!:D
One that was sent out for repair came back and failed to E39 within the first hour of operation.
Did you ever receive any details from your rep about the size of this first batch or how it's being dealt with? Not from the original /local rep.:(
We 're these failures covered under warranty?
Yes, our equipment vendor replaced every occurrence at no cost (other than downtime and inconvenience!)
I do NOT remember how our equipment supplier handled warranty service on their end.
Any information you can provide would be helpful. We simply cannot use the Torque Off inputs!
We have the Torque Off Bypass jumpered - possibly unsafe, I know, but for this implementation it is not a *LARGE* problem -- the equipment has safety relays and associated hardware!
Equipment has been running for about 15-16 months, jumpered!
Created Date: July 30,2013
Created by: james_t
Hi guys,
Just wanting to know if there were any similarities between your Kinetix 300 & the one's we are currently using. Here are my following details and this issue has only just started happening and the drives were installed in January. E39 would show up and then the machine would just freeze up in between doing a rotation.
WWYY- 3712
SN: 2097 - V34PR5348521237
FW: 1.71
Manual - 2097-IN001A-EN-P
Same details as above for our second one except WWYY is 2912.
Any help would be appreciated as it's causing a lot of delays with our down time until we reboot the system to get it up and running again.