# ppe



## HARRY304E (Sep 15, 2010)

captkirk said:


> Can anybody tell me what the proper ppe is for testing and measuring 480 equipment....? im sure its face sheild and gloves but what is the calorie count on the clothing..?



You can get the book here...:thumbup:


http://www.nfpa.org/catalog/product...clid=CIO6tby1n6kCFUPf4AodZjE9uw&cookie_test=1


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## Zog (Apr 15, 2009)

captkirk said:


> Can anybody tell me what the proper ppe is for testing and measuring 480 equipment....? im sure its face sheild and gloves but what is the calorie count on the clothing..?


No one can, the cal/cm2 rating of the clothing you need is determined by the avaible fault current and clearing time of the protective device. No one can determine based on voltage because it is not a direct factor.


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## AFOREMA1 (Nov 23, 2009)

The facility needs to have a study done by engineers to determine what your fault currents are on each disconnect over 50 volts. It depends on many factors what level of protection you need to wear .


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## RIVETER (Sep 26, 2009)

Zog said:


> No one can, the cal/cm2 rating of the clothing you need is determined by the avaible fault current and clearing time of the protective device. No one can determine based on voltage because it is not a direct factor.


I can tell you know your stuff. If their particular premise has not been mitigated to a Level Zero at the floor level it would be hard to tell what PPE to use.


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## mattsilkwood (Sep 21, 2008)

Does anyone have that chart in the 70E that you are supposed to go by if there is no study?


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## Zog (Apr 15, 2009)

mattsilkwood said:


> Does anyone have that chart in the 70E that you are supposed to go by if there is no study?


It is not that simple, to use the tables you still need to know the available fault current and clearing time of the OCPD.


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## MDShunk (Jan 7, 2007)

captkirk said:


> Can anybody tell me what the proper ppe is for testing and measuring 480 equipment....? im sure its face sheild and gloves but what is the calorie count on the clothing..?


As Zog points out, it gets downright complicated if there's no study done and stickers applied to the equipment. It's quite possible that no PPE in the world can protect you when taking measurements in some equipment, no matter if it's "just 480".


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## user4818 (Jan 15, 2009)

MDShunk said:


> As Zog points out, it gets downright complicated if there's no study done and stickers applied to the equipment. It's quite possible that no PPE in the world can protect you when taking measurements in some equipment, no matter if it's "just 480".


I've often heard the refrain that PPE makes the difference between open casket and closed casket when dealing with equipment with very high levels of available fault current. That video of the guy racking in the breaker at the refinery in Venezuela comes to mind.


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## Jmohl (Apr 26, 2011)

A properly completed arc flash survey with mitigation completed will provide the information required to select the proper PPE or to prevent personnel from working on equipment where no PPE selection will reduce a flash to a survivable injury. PPE selection is based not on No injury but an injury that is heal able in an incident. If the potential for fatality cannot be mitigated down to a survivable injury, then under no circumstance is the work to ever be performed live....:whistling2:


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## Zog (Apr 15, 2009)

captkirk said:


> Can anybody tell me what the proper ppe is for testing and measuring 480 equipment....? im sure its face sheild and gloves but what is the calorie count on the clothing..?


I will try to answer this the best I can, per 2009 70E (This will change when 2012 comes out in a few months). Working on exposed live parts (Including voltage testing) on 480V equipment is a HRC 2*. 

HRC2* requires at least:
8 cal/cm2 long sleeve shirt and pants (Or coveralls)
8 cal/cm2 flash suit hood, or 8 cal/cm2 rated face sheild with balaclava
Hard hat
Safety glasses
Hearing protcetion
Leather gloves
Leather boots

This is based on a maxium available fault current of 35kA and a max clearing time of 0.5 seconds. If this criteria is not met the tables may not be used and a detailed arc flash study is required. 

Now most electricians do not know how to determine the fault current and clearing times, so here is a little trick, and keep in mind this is just a general rule of thumb to aid you in determining if tables can be used. YOU SHOULD DO AN ARC FLASH STUDY so using my little trick should be done at your own risk. 

Go to the protective device that is protecting what you are working on (The main breaker of the panel or switchgear you are working in for example). Look at its AIC rating, if that is less than 35kA (For the above example) the fault current should be less than that (Assuming the device was properly applied, which sometimes it is not). Then look at the trip unit of the breaker, if it has an INST setting the clearing time should be less than 0.5 seconds.


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## BBQ (Nov 16, 2010)

Zog said:


> HRC2* requires at least:
> 8 cal/cm2 long sleeve shirt and pants (Or coveralls)
> 8 cal/cm2 flash suit hood, or 8 cal/cm2 rated face sheild with balaclava
> Hard hat
> ...



I always forget hearing protection ...


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## MDShunk (Jan 7, 2007)

BBQ said:


> I always forget hearing protection ...


I use it, but mostly because it's connected to the hardhat/faceshield. I'm uncomfortable with the fact that no one seems to make non-melting hearing protection.


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## Zog (Apr 15, 2009)

MDShunk said:


> I use it, but mostly because it's connected to the hardhat/faceshield. I'm uncomfortable with the fact that no one seems to make non-melting hearing protection.


If you have the correct head protection the hearing protection should not be expoased to heat, so it matters not.


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## MDShunk (Jan 7, 2007)

Zog said:


> If you have the correct head protection the hearing protection should not be expoased to heat, so it matters not.


Um... in this circumstance, but some categories only require hard hat and face shield. The hearing protection is exposed in those cases.


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## Zog (Apr 15, 2009)

MDShunk said:


> Um... in this circumstance, but some categories only require hard hat and face shield. The hearing protection is exposed in those cases.


 Only HRC 0, where the Ei is <1.2cal/cm2 anyways.


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## Wirenuting (Sep 12, 2010)

Zog said:


> Now most electricians do not know how to determine the fault current and clearing times, so here is a little trick, and keep in mind this is just a general rule of thumb to aid you in determining if tables can be used. YOU SHOULD DO AN ARC FLASH STUDY so using my little trick should be done at your own risk.
> 
> Go to the protective device that is protecting what you are working on (The main breaker of the panel or switchgear you are working in for example). Look at its AIC rating, if that is less than 35kA (For the above example) the fault current should be less than that (Assuming the device was properly applied, which sometimes it is not). Then look at the trip unit of the breaker, if it has an INST setting the clearing time should be less than 0.5 seconds.


Thank you Zog..
.
Looks like a bake & shake burial for me. 
Into a coffee can I go.


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## pudge565 (Dec 8, 2007)

AFOREMA1 said:


> The facility needs to have a study done by engineers to determine what your fault currents are on each disconnect over 50 volts. It depends on many factors what level of protection you need to wear .


Unless you work at the facility I work at. Then they just use the safety man and facility manager and an online calculator to find it.


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## Zog (Apr 15, 2009)

pudge565 said:


> Unless you work at the facility I work at. Then they just use the safety man and facility manager and an online calculator to find it.


More often than not using only the maximum availabel fault current will not result in the highest possible Ei, so ask them what the minimum requirements for thier calulation assumptions are. $50 says they have no idea.


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## mattsilkwood (Sep 21, 2008)

BBQ said:


> I always forget hearing protection ...


 Huh?:whistling2:


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## Jmohl (Apr 26, 2011)

Wirenuting said:


> Thank you Zog..
> .
> Looks like a bake & shake burial for me.
> Into a coffee can I go.


I always wanted to be put into a pringles can, loaded into the mk32, and air slugged into the Mayport basin!!!!!!!!


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## RIVETER (Sep 26, 2009)

Zog said:


> I will try to answer this the best I can, per 2009 70E (This will change when 2012 comes out in a few months). Working on exposed live parts (Including voltage testing) on 480V equipment is a HRC 2*.
> 
> HRC2* requires at least:
> 8 cal/cm2 long sleeve shirt and pants (Or coveralls)
> ...


I'll bet a great deal of guys here don't know what AIC rating is, and why it should be taken into account... but I bet you know.


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## Wirenuting (Sep 12, 2010)

Jmohl said:


> I always wanted to be put into a pringles can, loaded into the mk32, and air slugged into the Mayport basin!!!!!!!!


I was a TM on my first tour, GM on my second & a "Keeper of the Dragon" from day 1. 
This bake & shake coffee can shot would be my luck. LOL
.
http://www.youtube.com/watch?v=KQnVEp27f1s&feature=youtube_gdata_player


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## raider1 (Jan 22, 2007)

Zog and Marc, bring up a good point with voltage in relation to arc flash incident energy.

I did some consulting work for a local meat packing plant a few months ago and was reviewing their arc flash study. They have a medium voltage MCC with an arc flash incident energy level of 6.53 cal/cm2 and a hazard category of 2*, but down stream in the 480 volt switchboard the incident energy level was 130 cal/cm2 and exceeded the category levels.

Chris


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## BBQ (Nov 16, 2010)

RIVETER said:


> I'll bet a great deal of guys here don't know what AIC rating is, and why it should be taken into account...


They better as that is as important as the ampere rating on the breaker.

I can tell you most of our guys know what that means.


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## Zog (Apr 15, 2009)

raider1 said:


> Zog and Marc, bring up a good point with voltage in relation to arc flash incident energy.
> 
> I did some consulting work for a local meat packing plant a few months ago and was reviewing their arc flash study. They have a medium voltage MCC with an arc flash incident energy level of 6.53 cal/cm2 and a hazard category of 2*, but down stream in the 480 volt switchboard the incident energy level was 130 cal/cm2 and exceeded the category levels.
> 
> Chris


That is very common, it is all about the clearing time of the 480V main, a retrofit of the main and adding a maintnence switch is a great solution.


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## raider1 (Jan 22, 2007)

Zog said:


> That is very common, it is all about the clearing time of the 480V main, a retrofit of the main and adding a maintnence switch is a great solution.


I agree 100%.

Chris


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## MDShunk (Jan 7, 2007)

Put a bunch of running motors on the load side of the system, and that changes things remarkably as well.


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## Zog (Apr 15, 2009)

MDShunk said:


> Put a bunch of running motors on the load side of the system, and that changes things remarkably as well.


Yes, motor contribution is a huge factor, something those free on line calculators generally do not account for.


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