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 Post subject: Million dollar question
PostPosted: Wed Jan 26, 2011 11:43 am 
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Current Situation -- Your company has stated you will follow 70e. "good thing" The problem is you have A LOT of areas that are off the tables and not labels. You're working toward getting all the questions answered and labels on but it will be years before that is most likely done.

The Question - In a building you know to be off the tables. You're there to look at a 100hp +/- pump motor that is not working. You quickly realize you have a somewhat major problem because you have a conductor that is red hot and the lug on the switch/starter has pulled out of the switch.

Do you
A. Go find/call an engineer so he can do the quick math to let you know what ppe you need to operate the nearest breaker.
B. Call a trades helper and have them operate the breaker.
C. Roll the dice. Put on all the PPE you have on the truck and open the breaker with with the longest stick you have. It will be ok.


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PostPosted: Wed Jan 26, 2011 12:57 pm 
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If you're missing a phase on a motor, the overload protection should trip shortly after.

If it doesn't, call an engineering intern. He can do both A and B. :rolleyes:


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PostPosted: Wed Jan 26, 2011 2:22 pm 
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Location: Charlotte, NC
D. Use a remote operator to operate the breaker

Why would it take "years" to do your study and labeling?


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PostPosted: Wed Jan 26, 2011 2:59 pm 
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Option D

is what we are moving toward but haven't gotten there quite yet. Unfortunately 100+ buildings + 1 electrical engineer + NO money = YEARS to complete all surveys. Thanks for the input


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PostPosted: Wed Jan 26, 2011 8:35 pm 
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100questions wrote:
The Question - In a building you know to be off the tables. You're there to look at a 100hp +/- pump motor that is not working. You quickly realize you have a somewhat major problem because you have a conductor that is red hot and the lug on the switch/starter has pulled out of the switch.


Is the lug that is failing on the Line or the Load of the switch? If it was me, I would open the breaker upstream of the system supplying the pump (MCC Main Breaker, site main breaker, etc), using the best practices and ppe available for that breaker. This could include a 30 cal suit, longer stick to operate the breaker, safety person, etc.

Once the supply to the pump was verified off, open the breaker feeding the pump. If the failed connection is on the LOAD side of that breaker, install a barrier to shield the Line side and complete repairs. Depending on time for the repairs, leave the power off and complete the repairs. If the issue is on the LINE side, replace/repair while the power is off..

The problem that lots of people that do not have sufficient electrical safety knowledge have to be educated. They have to brought up to date so that they know how the rules to live electrical work have changed and how it will effect them. They need to know that there are some times where an outtage is required and will need to be planned and that is unavoidable..


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PostPosted: Thu Jan 27, 2011 4:36 am 
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best practices available

Glen1971 - am I understanding you correctly -- I can make a "guess" regarding PPE. If something bad happens and I get injured that guess won't matter?

Quote:
Is the lug that is failing on the Line or the Load of the switch? If it was me, I would open the breaker upstream of the system supplying the pump (MCC Main Breaker, site main breaker, etc), using the best practices and ppe available for that breaker. This could include a 30 cal suit, longer stick to operate the breaker, safety person, etc.


If guessing is ok can you tell me what ppe I should wear and how far I should be away? Here is a little background knowledge -- The last breaker we operated in this area we had to be 16 feet away at Cat. 3. The problem is I can't get that far away this time. NO I don't have a remote operator, a rope and pulley set up. I have a breaker handle.

Any additional input is appreciated. We are unfortunately in the middle of a situation that is a daily challenge. Thanks


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PostPosted: Thu Jan 27, 2011 5:57 am 
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I never said to guess... I said to use the "the best practices and ppe available for that breaker"..

How do you know the AF rating is over the top if you haven't done a study? You mentioned "16' and Cat 3".. Did you do your calculation correctly? Try revisiting your coordination study to drop the trip settings on the breakers.. Some people feel that the trips need to be "At the max" so that it won't ever trip, when in reality they won't trip at a lesser setting.

Personally I'd spend the time and the study done.. From the numbers you listed, I'd say some Arc Flash Reduction work is needed. I have done some inspections and the repairs required a total outtage and in some cases, the Utility was needed to do the isolation..


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PostPosted: Thu Jan 27, 2011 7:07 am 
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I'm missing something

Quote:
I never said to guess... I said to use the "the best practices and ppe available for that breaker"..

How do you establish the PPE without a study. We know the available fault current at the transformer and have gotten enough information to be able to label SOME things but not all.


Quote:
Personally I'd spend the time and the study done.. From the numbers you listed, I'd say some Arc Flash Reduction work is needed.

If we had your money we would get it done.

I may need ask this question in a better manner.

How do you all handle situations where you are WAY off the tables and need to shut things down NOW???????


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PostPosted: Thu Jan 27, 2011 9:39 am 
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100questions wrote:
If we had your money we would get it done.

I may need ask this question in a better manner.

How do you all handle situations where you are WAY off the tables and need to shut things down NOW???????


As I am a Contractor, here's what I'd do..
The PPE to operate the breaker doesn't exist... You can't remotely de-energize the system... They (whoever owns the breaker) won't spend the money to have an engineer do the proper calculations and reduce the hazzard... And having the Utility isolate it to be safe isn't an option.. I wouldn't do the work...

The bottom line is, you (as the worker) have the legal right to refuse unsafe work. Lack of PPE, lack of proper equipment (to isoalte the breaker safely), missing safeguards, and a potential for a deadly unsafe working condition would be my reasons why... If they (the client) wants to use another company, so be it.. I'd make sure to do my moral responsibility and let the other guy know what they are up against..

I don't own a bolt in it, and I ain't riskin my life for some P.O.S. equipment that isn't maintained properly or poses as a safety risk to me. There are some risks that are inherent to the job, but I am not going to add to them and run a larger risk of not going home in one piece at the end of the day...

JMO....


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