buzzlectric
Member
- Location
- Iowa
we have a custom built conveyor/cure line , we need to know the proper locations and quantities of e-stops we need. would this be covered in NFPA 79 manual?
E-stop location
- Thread starter buzzlectric
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petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: E-stop location
it might tell you where an individual pb needs to be, but not how many or how far apart they are to be spaced.
it might tell you where an individual pb needs to be, but not how many or how far apart they are to be spaced.
dbaird
Member
- Location
- Dayton, OH
Re: E-stop location
Just a thought...have you considered using a cable pull switch?
Just a thought...have you considered using a cable pull switch?
Re: E-stop location
NFPA-79 '02
10.7 Devices for Stop and Emergency Stop.
10.7.1 Location and Operation.
10.7.1.1 Stop and emergency stop pushbuttons shall be continuously operable and readily accessible.
10.7.1.2 Stop or emergency stop pushbuttons shall be located at each operator control station and at other locations where emergency stop is required.
So you must have one for every operator station. And there must be additional PBs wherever they are likely to be needed. The pull cable is a sound idea; otherwise you may end up placing a button every 5' down the conveyor so that one is always in reach.
NFPA-79 '02
10.7 Devices for Stop and Emergency Stop.
10.7.1 Location and Operation.
10.7.1.1 Stop and emergency stop pushbuttons shall be continuously operable and readily accessible.
10.7.1.2 Stop or emergency stop pushbuttons shall be located at each operator control station and at other locations where emergency stop is required.
So you must have one for every operator station. And there must be additional PBs wherever they are likely to be needed. The pull cable is a sound idea; otherwise you may end up placing a button every 5' down the conveyor so that one is always in reach.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: E-stop location
[ January 19, 2006, 10:08 PM: Message edited by: petersonra ]
I love stuff that is very helpful like this. you have to put one wherever one is needed.
[ January 19, 2006, 10:08 PM: Message edited by: petersonra ]
B
bthielen
Guest
Re: E-stop location
This is a very vague description.
How do you know you covered all of those places where one may be needed until the time you actually need it presents itself?
Using pull-cords or placing pushbuttons every couple feet may not cover every potential situation. If I'm wrapped up in a conveyor in such a way that I can't reach the pushbutton or pull-cord then the safety circuit is rendered ineffective. Sometimes that can be as simple as the angle at which I am trapped and not the distance to the safety switch actuator.
This does raise a question of what is adequate enough to be valid.
Bob
This is a very vague description.
How do you know you covered all of those places where one may be needed until the time you actually need it presents itself?
Using pull-cords or placing pushbuttons every couple feet may not cover every potential situation. If I'm wrapped up in a conveyor in such a way that I can't reach the pushbutton or pull-cord then the safety circuit is rendered ineffective. Sometimes that can be as simple as the angle at which I am trapped and not the distance to the safety switch actuator.
This does raise a question of what is adequate enough to be valid.
Bob
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: E-stop location
As best I can determine, there actually is no standard for this kind of thing.
OSHA only says you have to conduct a hazard analysis and somehow the outcome of that analysis tells you where the estops go.
As best I can determine, there actually is no standard for this kind of thing.
OSHA only says you have to conduct a hazard analysis and somehow the outcome of that analysis tells you where the estops go.
dbaird
Member
- Location
- Dayton, OH
Re: E-stop location
Most countries have "Risk Assessment" standards/procedures for working out this type of problem i.e. US has ANSI B11; Europe EN292.
Here is a good generalization of such procedures:
Guidelines
Most countries have "Risk Assessment" standards/procedures for working out this type of problem i.e. US has ANSI B11; Europe EN292.
Here is a good generalization of such procedures:
Guidelines
peteo
Senior Member
- Location
- Los Angeles
Re: E-stop location
The NFPA codes look more like fire protection than anything else (to me.) Possibly OSHA rules would apply here, or ANSI or NEMA standards. Not that I know anything about your situation. Your state's web site would be the place to start for specific requirements. A search of federal OSHA shows some research to be done, as in
http://www.osha.gov/pls/oshaweb/searchresults.category?p_text=conveyor&p_title=&p_status=CURRENT
Found an informative 4 page brief on conveyors in food industries (CE areas; touchproof, government interference, etc) at
www.hse.gov.uk/pubns/fis25.pdf
possibly you'll find something for your state like this
Might consider interlocked plexiglass shields, mats, and light curtains. The major interlock and safety curtain makers have reps here in the US you can talk to freely... Google 'safety relay' if you don't know anyone.
The NFPA codes look more like fire protection than anything else (to me.) Possibly OSHA rules would apply here, or ANSI or NEMA standards. Not that I know anything about your situation. Your state's web site would be the place to start for specific requirements. A search of federal OSHA shows some research to be done, as in
http://www.osha.gov/pls/oshaweb/searchresults.category?p_text=conveyor&p_title=&p_status=CURRENT
Found an informative 4 page brief on conveyors in food industries (CE areas; touchproof, government interference, etc) at
www.hse.gov.uk/pubns/fis25.pdf
possibly you'll find something for your state like this
Might consider interlocked plexiglass shields, mats, and light curtains. The major interlock and safety curtain makers have reps here in the US you can talk to freely... Google 'safety relay' if you don't know anyone.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: E-stop location
risk assessment is a tricky business.
by making minor changes in your assumptions you can get just about result you might want.
in the end, while you have to make the effort to do the risk assessment, it generally comes down to a gut feel.
I am of the opinion that the risk assessment is helpful in making the call, but I don't think it is definitive.
risk assessment is a tricky business.
by making minor changes in your assumptions you can get just about result you might want.
in the end, while you have to make the effort to do the risk assessment, it generally comes down to a gut feel.
I am of the opinion that the risk assessment is helpful in making the call, but I don't think it is definitive.
B
bthielen
Guest
Re: E-stop location
I doubt that a risk assessment, other than perhaps the fact that one was actually performed, would hold much water in reducing liability in court either.
I agree with Bob that it is only a tool that can help with the decisions about the safety cirtuit.
I doubt that a risk assessment, other than perhaps the fact that one was actually performed, would hold much water in reducing liability in court either.
I agree with Bob that it is only a tool that can help with the decisions about the safety cirtuit.
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