Operator safety standards incl NFPA 70E

[HCBFlash]

There are a few archived threads regarding some NFPA 70E stuff, but I'm looking for more insight(s).

I have an instance where a 1 VERY dangerous machine, and 3 more not quite as man-eating machines are being used. NFPA 70 (NEC) is being violated by no in-sight or readily accessible or labeled (identified) disconnects are present. That one's pretty clear.

The thing that's bugging me though, is that I have seen 3 or 4 instances where a control circuit blew, a touch screen program locked-up ("crashed"), a PLC output failed, a PLC input failed, and hardwired E-Stops had welded or damaged contacts, and one or more of them could not be shut-down. The branch circuit breaker had to be located and opened!

OK, I've been doing controls since, well, 1979(!)and I know about 10 things I know to be bad practices have been used in this system, but I'm having a hard time "chapter-and-versing" them. Similar to one very spirited discussion (thread237-70464), the local electrical inspectors aren't really all that good at this sort of thing.

Any particular insights on NFPA 70E, NFPA 79, or others?
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Please let us all know how this works out for you! and don't forget faq731-376

 

[dpc]

I'm not sure I understand your question, but electrical inspectors have nothing to do with NFPA-70E since it is not part of the NEC or any local codes that I'm aware of.

OSHA might have something to say about poor practices when it comes to implementation of control logic, emergency stops, etc, but that generally happens after the accident occurs.

 

[tygerdawg]

check out online PDF's of different vendor's safety controllers. For example, Allen-Bradley, Banner, Sick, others. I've seen them go into good, common sense discussions on why to use "modern method" safety devices and procedures, then back it up with references to commonly accepted standards.

Typically I've never gotten management motivated to do anything with safety issues by floating the possiblilty that "OSHA wouldn't approve of that". OSHA has had most of their teeth removed and typically only cause trouble AFTER the accident has occured. If you do a good job of explaining to your managers why they should do the right thing, then they still blow you off....well, it's time to leave.

TygerDawg

 

[dpc]

Tygerdawg,

The best approach to dealing with management on these types of issues is to write up a memo summarizing what you were told by your boss, or whomever, then ask them to sign it "just for your files". Tell him/her you just feel it's necessary to have a written record to reflect that your request was denied. Don't make a big deal out of it - just documenting the decision process.

This will sometimes give them pause to reflect on the relative priority of your request, and maybe try to pass the buck further upstream.

I agree that OSHA fines are not a big concern for most large corporations. However, management must keep in mind that worker's compensation laws will not shield them if negligence is involved. Courts in the US consider NFPA-70E an "industry standard" so failure to comply with a standard such as this is often interpreted as a failure to meet the normal "standard of care".

So the $100,000 OSHA fine could look like a insect bite after the plaintiff's red-meat lawyers get done with them.

 

[Rich2001]

Look at the OSHA 1910 Standard

http://www.osha.gov/pls/oshaweb/owastand.display_standard_group?p_toc_level=1&p_part_number=1910

, especially subsection S ELECTRICAL

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10135

Vita sine litteris mors est.

 

[sdl]

HCBFlash:

This is an interesting post. I got a phone call from a client who has suffered a dangerous failure in their PLC leaving equipment unprotected. They wont shut down to repair due to a management decision and are taking steps to rectify online. They had a serious incident with this same equipment a little while ago.

It is really hard to get management motivated about problems of this nature unless a serious incident occurs. What I would suggest is to do a risk assessment on the pieces of equipment and/or process to identify hte potential risk. I would also look at doing a SIL assessment as per IEC standards (61508 and I don't remember the machine standard off the top of my head). This will determine the level of integrity that the hardware (sensors, logic solver and final elements) should be designed to.

If you need help, I would suggest bringing in outside help to provide an independent viewpoint that might have some impact.

I hope this helps. There were a few good suggestions here, but the best one is that if management is not seriously concerned with their worker's safety, then is that a place you want to work?

sdl