Debate on MCC of ppe

[brother]

Well, this has been up before, and its back again. There are some 'preventive maintenance' that is being done on a mcc bucket for a fan. Theres no changing of the breaker, just some amp readings, voltage testing. when there is 'meggering done' the breaker is off, and it has a 'sheild' over the line side so the hot side is not exposed.

there are gloves used and safety glasses used when the amp readings and voltage testing is done, its 480 gear. I say 'technically' they have to have the 'arc flash' hood on, but maybe not the paints since its only their upper part thats expose. Others claim its not neccessary to have that, just the gloves, glasses, long sleeve cotton shirt.

I know most dont want that 'hood darth vader' suit on but if i read the NFPA 70e correctly then its suppose to be on. opinions please.

 

[ron]

First you have to figure out if Table 130.7(C)(9) applies at all by checking the appropriate notes.
Note 2. Maximum of 65 kA short circuit current available; maximum of 0.03 sec (2 cycle) fault clearing time.
If those two things are true, then just to open the cover, you may need to check Note 3. Maximum of 42 kA short circuit current available; maximum of 0.33 sec (20 cycle) fault clearing time.
I would think maybe Class 2* is need for amp probing, which is pretty close to the application.

If the notes do not apply, then you must do the detailed calculations to figure it out.

 

[billsnuff]

sometimes a head sock and face shield are equivalent

see note 10 of 130.7(C)(10)

 

[zog]

I say 'technically' they have to have the 'arc flash' hood on, but maybe not the paints since its only their upper part thats expose.

This is a huge myth, you have no idea where that arc will go, arc are very unpredictable and will not always come straight of of the panel. Go to this link, click on "Video library", and watch clip #7 on the top 10 clips. http://www.westexinc.com/

Others claim its not neccessary to have that, just the gloves, glasses, long sleeve cotton shirt.

I know most dont want that 'hood darth vader' suit on but if i read the NFPA 70e correctly then its suppose to be on. opinions please.

Ron nailed it, if you dont hav ean arc flash label on the equipment form an analysis, then follow the tables (Be sure to read all the notes).

Sounds like your plant is in serious need of some 70E training, dont listen to those other guys, you seem to have a better understanding than they do.

 

[buldogg]

sometimes a head sock and face shield are equivalent

see note 10 of 130.7(C)(10)

Salisbury has a hardhat/faceshield/chin guard combo that we use instead of having to wear "head sock"

 

[billsnuff]

Salisbury has a hardhat/faceshield/chin guard combo that we use instead of having to wear "head sock"

The face shield center, below is good for HRC2. In order be safe at HRC2*, you will need the 'headsock' or balaclava on the left, or you could wear the

Darth Vader Hood below

Note 10 is only found in HRC2*

 

[jim dungar]

Salisbury has a hardhat/faceshield/chin guard combo that we use instead of having to wear "head sock"

Changes in NFPA 70E-2008 limit the use of a face shield only. HRC=2 and higher locations require at least a 'sock' to protect the ears and neck.

My newest Cat 4 hood is fairly comfortable, I prefer it over a face shield and sock. It has a battery operated ventilator which prevents the inside from fogging and the shield is transparent enough that I can read data from inside an MCC bucket aided only by a flashlight (and of course my bifocals).

 

[billsnuff]

Changes in NFPA 70E-2008 limit the use of a face shield only. HRC=2 and higher locations require at least a 'sock' to protect the ears and neck.

130.7(C)(10)

Note 7. A face shield with......a mininum rating of 8 cal/cm2 for HRC 2 with wrap around guarding to protect not only the face, but also the forhead, ears, neck .............is required.

Note 10. ..........and a balaclava

just looking for understanding (mine) to see if i read this correctly.

HRC2 note 7

HRC2* note 10