I am a safety person in a large manufacturing plant and was always taught to stand to the right side of a disconnect, use your left hand and face away, then throw the handle. Is there a standard that says you can not stand in front of the disconnect and operate the disconnect? I am having to prove that it is not ok to stand in front, even if you have your 'arc flash' PPE on. Thanks in advance for any help you can give me.
Operating a disconnect
- Thread starter Safety869
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petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Safety869 said:
are the disconnect switches rated to "break" the FLA of the motor?
are they rated for the available short circuit current?
personally, I think the approach you are taking is "safer" than standing in front of the switch when operating it, but maybe not "safe".
the level of PPE for arc flash safety varies from LS shirt and safety glasses to the space suit. even the space suit cannot protect you from all arc flash hazards, depending on the available energy.
in a lot of cases, there actually is no arc flash hazard at all. you have to do the leg work to determine if the hazard exists first, and then do what it takes to mitigate it.
cschmid
Senior Member
- Location
- Northern cold country
The safety issues are real but I know of nothing that requires the left hand rule..I am not even sure OSHA requires the use of PPE to operate a disconnect..If the disconnect is complete the way the manufacture send it and installed according to the manufactures specifications..the disconnect is safe for anyone to throw and lock out with no special equipment required unless it was specified by manufacturer..You as a manufacturing company can make your rules more restrictive for you employees at your will..I would just caution you not to be to restrictive as to cause unnecessary down time which would cause an increase in costs..You can actually make the left hand rule inclusive or restrictive by location which I think is more warranted than complete inclusiveness..just my 2 cents worth..
Years ago I worked with an old electrician who used to close his eyes and duck when ever he threw a disconnect. I thought it was quite humorous, but I am sure sometime in his life something happened that made him think it was a good idea. Disconnects have a built in safety factor and the upstream o.c. protections should open long before the disconnect is jepordized. On the other hand, I know an electrician who lost a thumb and index finger when he energized a defective 800 amp breaker. He won a $2 mil settlement from SqD and has not worked since, although he now has to hold his beers with his left hand.
- Location
- Massachusetts
celtic said:
Agreed.
Not long ago I had to open a live 480/277 panel just for a look, I had my helmet and safety glasses but I realized I was wearing a fleece pullover.
I had already learned that pullover melted quickly when uni-bit chips landed on it. The thought of having it peeled from me after a flash made me go back to the truck and get the fire retardant LS uniform shirt I have been provided with.
- Location
- Massachusetts
celtic said:
Yeah it kind of hit me all of a sudden. This could be ugly
- Location
- Massachusetts
Pretty cool 30 second video unless you where standing there.
480 volt 3-phase Arc Flash Demonstration
480 volt 3-phase Arc Flash Demonstration
Thank you for all your information. The panels are PIP panels at 480v, all of them have NFPA labels, either hazard class 0 or 2. All proper PPE is being worn. I just wondered if there was a standard for the 'left hand operation'. We are slowly getting our plant to hazard class 0, having the proper fuses upstream of the disconnect.
The left-hand rule is a trade practice passed on through apprenticeship. It is not to be found in any code. It starts with old electricians needing to operate disconnects on an open panel. It doesn't take too many flashes to convince someone where their face should be, or in this case where it should not be. From there it just became the standard practice.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Malden Mills makes a version of their standard 200 weight fleece in Nomex rather than Polyester. Feels exactly the same, has essentially the same comfort qualities, but it doesn't melt and self extinguishes. I got a sample of the fabric, and had fun passing it through a gas flame; the face charred but no melting was evident.
If you are willing to spend $200-$300 for a pullover that would be $20 in Polyester at 'Old Navy', then look up 'Chuck Roast'
-Jon
If you are willing to spend $200-$300 for a pullover that would be $20 in Polyester at 'Old Navy', then look up 'Chuck Roast'
-Jon
zog
Senior Member
- Location
- Charlotte, NC
You want to stand on the hinged side of the cabinet door, not all open the same way, but this rule is a common practice and not found in any US standard.
OSHA bans the wearing of meltable fabrics when arc flash hazard exists but currently does not require arc rated clothing, thats a 70E requirement but is enforceable by OSHA through the general duty clause.
Safety 869, your origianal post mentioned turning your head away, bad idea when wearing HRC 2 PPE, the face sheild turns into an arc scoop in that situation.
OSHA bans the wearing of meltable fabrics when arc flash hazard exists but currently does not require arc rated clothing, thats a 70E requirement but is enforceable by OSHA through the general duty clause.
Safety 869, your origianal post mentioned turning your head away, bad idea when wearing HRC 2 PPE, the face sheild turns into an arc scoop in that situation.
Hope you don't get mad....winnie said:
$90
http://www.chuckroast.com/fire-safety/fr-c1965b.php
www.chuckroast.com (home page)
(That makes me hungry
)
zog
Senior Member
- Location
- Charlotte, NC
Not 70E compliant (Chuck roat pullover), noy saying you cant wear it but it does not meet any requirements for any HRC.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Very cool. Prices have dropped considerably since I first looked at them.
Almost worth it just for a pullover that won't have little burn holes from sitting around a camp fire.
-Jon
Almost worth it just for a pullover that won't have little burn holes from sitting around a camp fire.
-Jon
brian john
Senior Member
- Location
- Leesburg, VA
And you have proof of this? Please do not depend on this philosophy!
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