MCC bucket lock out tag out

[cornbread]

At our plant it is standard practice to remove the line fuses when performing a MCC bucket lock out tag out. Naturally we use the proper PPE, insulated gloves, FR clothing & face shields when throwing the disconnect and removing the fuses, unless the Arc Flash label tells us otherwise. My question is two parts.

1. After locking out the bucket and removing the fuses, we consider the bucket electrically safe. Is this an accurate statement?

2. Typically our electric crew is prepping the electrical for another trade, so once the prep work is done the mechanics will throw their locks on the bucket. It may be several day before we are asked to re-install the fuse and bring the equipment back on line. If you agree that the bucket is in an electrical safe condition from the lock out then you would not need any PPE to re-install the fuses? I personally play it safe and wear the same PPE when re-installing the fuses. Some of my fellow co-worker insists that PPE is not needed since the bucket was properly locked out.

I?m going to keep on doing what I feel is best for me, but wondering I am being overly cautious?

 

[billsnuff]

i am being very carefull with this answer.

Electrically Safe Work Condition

determine all source of power

open the disconnect for each source

verify the blades are open

apply LOTO

check for voltage live-dead-live

apply grounds

if you have personal knowledge that all of the above is true......

 

[zog]

1. After locking out the bucket and removing the fuses, we consider the bucket electrically safe. Is this an accurate statement?

Bill said it well, you also need to verify absence of voltage (Live-Dead-Live test), ensuring your meter is working properly. Some cases may aslo require protective grounds.

2. Typically our electric crew is prepping the electrical for another trade, so once the prep work is done the mechanics will throw their locks on the bucket. It may be several day before we are asked to re-install the fuse and bring the equipment back on line. If you agree that the bucket is in an electrical safe condition from the lock out then you would not need any PPE to re-install the fuses? I personally play it safe and wear the same PPE when re-installing the fuses. Some of my fellow co-worker insists that PPE is not needed since the bucket was properly locked out.

I?m going to keep on doing what I feel is best for me, but wondering I am being overly cautious?

After it is verified dead, you would not need PPE, but the next thing you will do is remove the lock and renergize, which will require PPE anyways so why not wear the PPE to install fuses, better safe than in a burn unit.

 

[masterelect1]

Why does one need PPE to re-energize as the door should be closed and secured, whether it is an MCC bucket or a combo starter? That would be the equivalent of wearing PPE every time one threw the disconnect, for whatever reason.

 

[petersonra]

I don't see any reason to pull the fuses. Just opening the switch should be adequate.

 

[zog]

Why does one need PPE to re-energize as the door should be closed and secured, whether it is an MCC bucket or a combo starter? That would be the equivalent of wearing PPE every time one threw the disconnect, for whatever reason.

Yes it is, and the 70E requires PPE to do so.

 

[weressl]

I don't see any reason to pull the fuses. Just opening the switch should be adequate.

Job security, my dear men.

 

[ironman3452]

best practice is allways, until it is deemed dead, wear ppe in or out, just is a good practice to get into,

 

[masterelect1]

Yes it is, and the 70E requires PPE to do so.

Are you telling me that if I enter a MCC to turn off the disconnect for a bucket and then apply a LO/TO to same that I must wear PPE? I think not.

 

[masterelect1]

I don't see any reason to pull the fuses. Just opening the switch should be adequate.

Applying Tags Only OSHA 1910.333

Tags are allowed to be used without locks where locks cannot be applied to a given installation or if the employer demonstrates that tagging procedures provide safety equivalent to a lock.

However, if a tag only is used, one or more safety measures must be used; one is removal of fuses. This does not have to be done if a lock is in place.

 

[weressl]

Are you telling me that if I enter a MCC to turn off the disconnect for a bucket and then apply a LO/TO to same that I must wear PPE? I think not.

Logic - and myself - would agree with you, but 70E does not make distinction between On or OFF operation of the disconnect.

 

[billsnuff]

70e 2009

70e 2009

Are you telling me that if I enter a MCC to turn off the disconnect for a bucket and then apply a LO/TO to same that I must wear PPE? I think not.

i'm afraid i must disagree. Operation of a fused switch 600 V Class MCC is HRC 0, which requires Non melting or untreated natural fiber LS Shirt and Pant, safety glasses, hearing protection and leather gloves (as needed).
that is PPE for HRC 0.

Now, even if you lock it out, it is not in an electrically safe work condition until you conduct a live dead live test to check for the absence of voltage, so you can do no more with out PPE for HRC 2*. JMSO

 

[masterelect1]

Logic - and myself - would agree with you, but 70E does not make distinction between On or OFF operation of the disconnect.

So, and I'm serious here;

Example: an operator in a manufacturing plant KNOWS that in MCC #4 that bucket F5 labeled -
"line #1 main supply" will kill all power to his machine so that he can perform a simple task such as clean up, that before he can pull the disconnect and apply his LO/TO on that bucket with its closed and bolted door he has to put on PPE's ??

 

[weressl]

So, and I'm serious here;

Example: an operator in a manufacturing plant KNOWS that in MCC #4 that bucket F5 labeled -
"line #1 main supply" will kill all power to his machine so that he can perform a simple task such as clean up, that before he can pull the disconnect and apply his LO/TO on that bucket with its closed and bolted door he has to put on PPE's ??

See reply above: http://forums.mikeholt.com/showthread.php?p=1001371#poststop

Trust, but verify.

 

[billsnuff]

it depends

it depends

so that he can perform a simple task such as clean up, that before he can pull the disconnect and apply his LO/TO on that bucket with its closed and bolted door he has to put on PPE's ??

first you have to be a qualified person in appropriate PPE to pull a disconnect depending on HRC #, according to 70E.

i don't know what your LOTO rules say but OSHA 29 CFR 1910.147 says:

1910.147(d)(6)
Verification of isolation. Prior to starting work on machines or equipment that have been locked out or tagged out, the authorized employee shall verify that isolation and deenergization of the machine or equipment have been accomplished.

their are requirements to be an authorized person as well.

link to LOTO Std

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9804&p_table=STANDARDS

further 1910.3xx (sub part S - electrical) also has requirements for PPE, but they are not as clear as 70E. FWIW

 

[masterelect1]

sorry to belabor the point, but are you making a distinction between 'pulling" the disconnect as opposed to "turning off" the disconnect.

I have not been in the manufacturing arena for 3+ years so I am somewhat surprised by this.

 

[billsnuff]

sorry, bad term........moving the handle of the disconnect to the off position.

we can't rack gear here, (i work in a factory) main gear is 90 cal/cm2 line side. have to have POCO shut off power. we've had the Arc Flash Study completed but POCO won't reduce their fuses or we could get to 20+ cal/cm2. so guess who's working President's Day.....