alan_505
Lifetime Supporting Member
If he is using PF525's then that HIM will not work, he will need a 22-HIM-A3 and they look to be a lot dearer.
Teacher needs help with Motor Controls
- Thread starter tim_callinan
- Start date
Ah ****....I didn't notice it was a 20.
https://www.needco.com/product/deta... feed&utm_content=free google shopping clicks
Can't update the post, but that's a 20 I inadvertently posted. Here's the 22
https://www.needco.com/product/deta... feed&utm_content=free google shopping clicks
I would suggest that you approach this very systematically. You community college should have rules in place to ensure facility safety, these standards should also have substandards for equipment.
If NOT the case, please conduct a proper risk assessment. From a machine standpoint, you should be able to put a safety circuit as a supervision which doesn't allow your students to make a mistake:
Potentially the EStop circuit can be the 1st step, then the next step can be motion. Perhaps you can also have something like a deadman switch to turn off motion, and supervisory max speeds to simulate a bench-environment.
Maybe you should consider pre-made trainers, or at least copy the features of trainers like guarding the rotation area, making the HV lines quick disconnect and insulated, just hedge the risk.
PPE is an important control, but elimination is the 1st issue you need to solve.
https://en.wikipedia.org/wiki/Hierarchy_of_hazard_controls
Also, you should have a circuit pre-evaluation in your class, and your students should not be able to energize anything before your checklist has been checked.
You can also take this opportunity to teach people about hazardous energy control including designing LOTO capable machines - even for testing.
Source: Had a "Collaborative" Universal Robot try to kill me when I changed the speed from within the AB PLC's UDT from What I thought was really slow 0.2 -> 5%.
In fact, 0.2 in the UDT represented 20%, and 5 somehow worked as a memory indirection and I remember reading the teach pendent went to 1400% of the max allowable UR speeds.
Moving faster than you can even move it manually.
Way beyond the Teach Pendant's allowed memory. The UR Killerbot was in fact not respecting it's own supervisory limits. I was saved by a workbench support beam, otherwise it woud have been a bad day for me testing this robot in my controls lab.
If NOT the case, please conduct a proper risk assessment. From a machine standpoint, you should be able to put a safety circuit as a supervision which doesn't allow your students to make a mistake:
Potentially the EStop circuit can be the 1st step, then the next step can be motion. Perhaps you can also have something like a deadman switch to turn off motion, and supervisory max speeds to simulate a bench-environment.
Maybe you should consider pre-made trainers, or at least copy the features of trainers like guarding the rotation area, making the HV lines quick disconnect and insulated, just hedge the risk.
PPE is an important control, but elimination is the 1st issue you need to solve.
https://en.wikipedia.org/wiki/Hierarchy_of_hazard_controls
Also, you should have a circuit pre-evaluation in your class, and your students should not be able to energize anything before your checklist has been checked.
You can also take this opportunity to teach people about hazardous energy control including designing LOTO capable machines - even for testing.
Source: Had a "Collaborative" Universal Robot try to kill me when I changed the speed from within the AB PLC's UDT from What I thought was really slow 0.2 -> 5%.
In fact, 0.2 in the UDT represented 20%, and 5 somehow worked as a memory indirection and I remember reading the teach pendent went to 1400% of the max allowable UR speeds.
Moving faster than you can even move it manually.
Way beyond the Teach Pendant's allowed memory. The UR Killerbot was in fact not respecting it's own supervisory limits. I was saved by a workbench support beam, otherwise it woud have been a bad day for me testing this robot in my controls lab.
no way that I know of to power just the control circuit on a 525.
is a cheap lab laptop out of the question for changing parameters? you can get a whole lot more out of laptop programming as well when it comes to teaching.
to know the exact right type of safety gear you would need someone competent in electrical hazard studies to come by and see what the cal rating is on the cabinet, which would give you an exact fit for what you need.
but you don't want that unless you want them all wearing full frock, face shield, etc.
Ain't that the truth. I have a customer with a Centerline MCC. One bucket is an empty bucket with a 24VDC supplied Stratix Switch. They were lazy and rated the whole MCC as a particular Arc Flash rating, so to go into this empty bucket with a Stratix Switch to move a network cable required a moon suit, rubber/leather gloves and a face shield.
BOWILLY
Member
As a teacher at a community college, you will be entrusted with the health and safety of young adults. Ensure that your classroom H & S rules meet or exceed the standards set by your school, your municipality and your state.
Specifically, gloves (voltage rated with leather covers) should be used when troubleshooting live electrical circuits. The risk of shock is the immediate concern. As to arc flash/blast - my training has taught me that the risk is near zero with voltages under 250V. Marry all this with LOTO training. The key in the lockout lock tells me either training isn't done or it hasn't been monitored. This training should verify absence of voltage before PPE can be removed. A rule of thumb I've always used and taught is to assume everything is electrically live until proven otherwise. Once you have everything set up AND before turning the students free, a formal risk assessment should be performed. This would have caught the exposed motor shafts .
Specifically, gloves (voltage rated with leather covers) should be used when troubleshooting live electrical circuits. The risk of shock is the immediate concern. As to arc flash/blast - my training has taught me that the risk is near zero with voltages under 250V. Marry all this with LOTO training. The key in the lockout lock tells me either training isn't done or it hasn't been monitored. This training should verify absence of voltage before PPE can be removed. A rule of thumb I've always used and taught is to assume everything is electrically live until proven otherwise. Once you have everything set up AND before turning the students free, a formal risk assessment should be performed. This would have caught the exposed motor shafts .
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