N F P A 70 E

I recently saw an ad for an Electrician with the following note:

"Perform duties in accordance with all Safety procedures including those recently mandated by NFPA 70E".

Any of you guys out there doing this???

regards.....kc

Nope.
My high end is 480. In fact, It's 480, 24dc, or 0-10Vdc. I know it, respect it, but I'm not wearing funky duds to play with 480. Never have needed it so far, and I'm not seeing a need to.

I have to agree, though 208 or 240 usualy is the most I am around. Occasionally 480.

I am sometimes around,4160/2400, or 13,800/7200, but my personnal safety factor puts me so far away that a hotstick isn't long enough!

NOTE: One of the worst shocks that I ever recieved was 24 volts DC. But it did invole two 8D batteries on a CAT D399 Genset, and one contact point was my thumb, right about where I had a metal sliver......OUCH!

Electrical work standards

Though it is not law yet, you will find more companies working to this standard. Nfpa-70E sets standards for hot work permits and proper tools and clothing. These are minimum standards trying to get the accident and incident aka "near misses," reduced to zero. Levels of training and accident investigation procedures are also mentioned. Im sure there are other areas it covers also, havnt seen the paper recently. With the skilled worker shortage here, this will not be implemented here any time soon.

Rumor going around work is that the new electrical safety program is going to be based on NFPA 70E. I'm scared to know...

I'm setting up an entire factory right now, and rule 1 is disconnects next to everything.
Rule 2 is marking the 24 & 480 CLEARLY.
Rule 3 if it's 480 we need to work on, we lock it out. No exceptions.

Because we use the 480 on all the motor & power connections, it forces everyone to take it seriously.

We just began to slowly implement NFPA 70E, we already have a good safety program, but we need to do more of the arc flash studies.

Electrical Safety

Just knowing about 480 isn't enough. Locking it out can also lead to a false belief that you can't get hurt. Take changing the rotation on a motor. Most will do it at the local disconnect (yes I put them on all motors). If its off and locked out, then the top will be hot. Yes I know everyone knows it's hot and stays away, but NFPA 70E doesn't just allow it. There is still the potential. To fully comply with NFPA 70E, you would have to lock it out at the MCC and then after wearing the proper PPE and verifying it is not energized, then you could change it at the disconnect without all the silly gear.

I think what most people are assuming is that you have to wear the blast suit to change a light bulb. These rules aren't designed to be scary, they are designed to protect you in the extremely unlikely event that something bad happens. The proper method is to do an arc flash and fault current study on everything you have in your plant. I know it's expensive and I've been doing it this way for 40 years who are NFPA to come in and tell me something different, but it is truly necessary. I've worked at many plants that have no idea of the magnitude of the fault current at their gear and I can't believe it. How can you properly design a panel without knowing this. All 30 Amp breakers are not the same (look up AIC). IF this is done, then the rest of the calculations aren't that bad, but they should still be done.

You might also be surprised that if your company (or you) deside to do it correctly instead of the simplified method (which is way overkill in most cases), you might be plesantly surprised. I just the plant that I work at and it is huge compared to most (1.8 million SF and over 600 different machines with a power bill in the 10's of millions per year). After looking at the simplified method, we spent the money for SKM Powertools. That made everything very easy. Since we have to huge substations to supply our plant, the available fault current is pretty large.

After making some adjustments to the trip settings of the breakers, most of the equipment at our plant is level 0 or -1 (yes, negative 1). That means that the workers are protected at cotton clothing. Every piece of equipment is marked with the amount of energy available, the category, the approach distance for flash hazard (many are less than 4 inches) and the required PPE. Even my MCCs are still cat 0 so no suits are required.

I've heard a lot of moans and groans and I can't believe its, but when it comes down to it, the employer is responsible for you if you get hurt, they will be fined by OSHA if you get hurt, they will still pay workmans comp if you get hurt and many will feel bad if you get hurt. It's in their best interest to implement these rules and they need to do it.

If anyone needs any information about all this, we are almost fully compliant here, I will be glad to help and explain or show you anything.

Quick story: My father-in-law recently retired from Cutler-Hammer. He knew a guy who worked in a panel shop and was in the habit of setting his tools on top of the main 480V breaker.

Once, he was called to work on a installed panel. You can guess what he did. Pretty serious damage to his hand. Luckily, the height of the breaker shielded the rest of his body.

We are starting to look at changing our designs so there are no boxes that mix 24V and 480 and eliminating 120V as much as possible. This will allow as much work on live equipment at possible.

Remember, electricity kills.

It always amazes me to hear how people go out of their way to not be safe. Their rational is "I've been doing it forever and I've never been seriously injured". But, get several people together and listen to the number of horror stories they have first and second hand knowledge of.

Control designers would never "program" PLCs with the same cavalier attitude that many of them take towards electrical safety.

If I had my way, PLCs would never be in the same cabinet with any voltage over 120VAC and all I/O would be wired with 24VDC control.

NFPA 70E is really good for electrical safety. OSHA is really pushing for Arc Flash Protection. We had implemented most of 70E except this. It is really not hard at all. Plus after you see a few videos about Arc Flashes you will begin to understand why OSHA is pushing it.

Even if you do follow Arc Flash Protection procedures have all of your panels properly labeled for Arc Flash Protection. That is what OSHA is looking for.

Also Arc Flash Protection is required on all panels above 50 volts. Many states, I know Virginia has, have already past laws requiring this

Remember, electricity kills.

Click to expand...

More specificly according to the NFPA 70E the majority of electrical accidents are from arc flash burns and not from electrical shocks

I was told at an EH&S conference last year that our corporation is implementing NFPA70E this year. Scared the **** out of me at first. I thought of all the NASA suits that we would have to wear. Then I got to reading the books some and realized that we already use a good bit of the safety procedures. We will still have to do the arc flash studies, labelling, and a few changes to our habits. We will have a consultant visiting in the next few months to help us get going in the right direction.



Dale

We recently had our first taste of NFPA 70E training here. Being a designer with an OEM I was looking at this more from the standpoint of how do I make my customers lives easier in the new NFPA 70E environment.

I'll just reiterate a couple of things that were already said.
1) Do the fault enenrgy calculations. Like brucechase said you will probably be pleasantly surprised by the results. Unless you are connected directly to a substation with HUGE electrical cables or you haven't taken coordinated overcurrent protection seriously, your available fault energy will probably be lower than the quick tables in NFPA 70E indicate.

2) As Jim Dungar ans Rick Densing said, separate your high fault energy stuff (208/240/480/etc) from the low fault energy stuff. This will remove most of the restrictions on working on the items you usually work on, like the PLC and I/O.

TWControls posted a reference to results of arc flash. In our training we saw a real short video bit of an arc flash test performed with a dummy in the path of the arc. It was really impressive. However, to temper that a bit, this demonstration was done for effect. The available fault current in that experiment was intentionally very high. That's one big reason for knowing your available fault current and limiting it where possible. Even with the right clothing, 2500 pounds per square foot of blast force will not feel real good.

Keith

Kind of funny that this post came up. I'm doing Arc Flash calculations as we speak. The results aren't bad at all. The biggest thing I am seeing is we may have to change our uniforms to make sure they are flame resistant and the proper cals