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Joined: Mar 2005
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50V circuits aren't typically fed from 3000kVA transformers. Are we talking today, or in 2011 when AFCI and GFCI will be required for all commercial applications to? Either way, I'm going to go with 4mA.

Arc Flash PPE Clothing, LOTO & Insulated Tools
Joined: Sep 2007
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PPE is required for voltage testing, i.e., "00" or "0" voltage rated gloves with leather protectors, plus voltage rated test equipment. This also means the proper category. CAT I, II, III, IV. The closer to the utility source the higher the category instrument required for safe testing.
See NFPA 70E Table 130.7(9)(a) for Panel Board Rated at 240V and Below for PPE required.

Joined: Jul 2004
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50v at 100a will still give you quite an arc, perhaps more that "dry hands" will handle. I saw a guy melt a wedding ring, permanently scarring his finger at 1.5v.


Greg Fretwell
Joined: Jul 2001
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JBD Offline
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Originally Posted by richxtlc
PPE is required for voltage testing, i.e., "00" or "0" voltage rated gloves with leather protectors, plus voltage rated test equipment. This also means the proper category. CAT I, II, III, IV. The closer to the utility source the higher the category instrument required for safe testing.
See NFPA 70E Table 130.7(9)(a) for Panel Board Rated at 240V and Below for PPE required.


If an arc flash study has not been performed then voltage testing PPE also requires a Hooded Face Shield. The task tables show this as 2*.

I believe with the next edition of NFPA 70E, face shields will be required for all testing with hand held meters.

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Zog Offline
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WOW! About everyone here is in serios need of 70E training.

I will start from the top.



MV/HV Testing Specialist, "BKRMAN"
Joined: Sep 2005
Posts: 120
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Zog Offline
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Originally Posted by Yoopersup
NFPA says Hazard Analysis anything operationing at over 50 volts . That Means Mcc's, Switchgear, Panels 120/208
277/480 & up and up. I take it that includes Panels and Equipment over 50 volts Period. Example PLC 120 volt feed??
fire alarm Panel. 120/240 volt feed.
X ray Machine ect ect. Where is the Break Line and where in 70E does it say the break line is?? NEC 110.16 Spells out where ist sticker goes . 70E from what I see Doesn't where second one is required except Fer Hazard analysis. 2008 NEC adds Electrical Equipment to 110.16.look up equipment in definations in NEC umm this gets interesting??


Yoserup, 70E requires SHOCK protection above 50V, not arc flash protection, refer to the LAB< RAB, and PAB's listed in the tables for the voltage you are working on. 70E does not require labels, as someone else mentioned, the NEC does (Generic) but the 2008 70E will require labeling that includes the PPE required or the Ei from the analysis on everything the NEC does.

IEEE 1584 says an arc will not be self sustaining on systems less than 240V fed by a transformer less than 125kVA (However some testing group disagree with this), so that means you do an analysis above that point and use the 70E tables below that.


MV/HV Testing Specialist, "BKRMAN"
Joined: Sep 2005
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Zog Offline
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Originally Posted by JBD
There is no IEEE 1584 calculation for single phase circuits regardless of voltage so they are not normally part of arc flash studies therefore they rarely have a cal/cm² sticker on them.

If the calories or Hazard Risk Category (HRC) are not known you are only left with the 70E task tables. If the circuits are current limiting then you may be able to take advantage of the provisions that allow a reduction in the normal task table HRC.

How come the Wisconsin and UP guys are up at this time of night, don't you have to get up and shovel in the morning?


All true, however, the 2008 70E will not have this provision because it has been proven not safe and is abused. I bet 95% of the cases were the resuction was used the person did not know the fault current available.


MV/HV Testing Specialist, "BKRMAN"
Joined: Sep 2005
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Zog Offline
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Originally Posted by SteveFehr
Originally Posted by JBD
Originally Posted by Yoopersup
All over 50 volts covers a lotta ground.


Yasure youbetcha.
Luckily, appropiate PPE is rarely a 40 cal "moon suit".
PPE for 51V is a cotton shirt and dry hands, isn't it?


No, it depends on what equipment you are working on and which boundaries you are crossing but cotton shirt and dry hands don meet any requirement 9Sorry if you were joking about that)

Last edited by Zog; 02/29/08 10:01 PM. Reason: Forgot to quote

MV/HV Testing Specialist, "BKRMAN"
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Zog Offline
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Originally Posted by gfretwell
50v at 100a will still give you quite an arc, perhaps more that "dry hands" will handle. I saw a guy melt a wedding ring, permanently scarring his finger at 1.5v.


Gfretwell. No it wont, but if you mean a 100A circuit the available fault current is probally much higher (Depends on the source) lets guess around 2000A, that will make some fireworks.

Last edited by Zog; 02/29/08 10:03 PM.

MV/HV Testing Specialist, "BKRMAN"
Joined: Sep 2005
Posts: 120
Z
Zog Offline
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Originally Posted by JBD
Originally Posted by richxtlc
PPE is required for voltage testing, i.e., "00" or "0" voltage rated gloves with leather protectors, plus voltage rated test equipment. This also means the proper category. CAT I, II, III, IV. The closer to the utility source the higher the category instrument required for safe testing.
See NFPA 70E Table 130.7(9)(a) for Panel Board Rated at 240V and Below for PPE required.


If an arc flash study has not been performed then voltage testing PPE also requires a Hooded Face Shield. The task tables show this as 2*.

I believe with the next edition of NFPA 70E, face shields will be required for all testing with hand held meters.


Niether of these statements are true, the PPE requirements depend on the charteristics of the system you are working on.

The only change in 2008 regarding facesheilds will be allowing a arc rated facesheild with Balakava to be used in place of the switching hood for HRC 2* tasks.

Last edited by Zog; 02/29/08 10:02 PM. Reason: Forgot to add quote

MV/HV Testing Specialist, "BKRMAN"
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