# 800 amp Commercial Service upgrade - 16 meters occupied units



## brian john (Mar 11, 2007)

Amp clamp each service and try to force loads on I would bet (though I could be wrong)

2-400 amp MLO panels with 100 amp CB's have all the temp set up and use clear taps for connecting, if the loads exceed 100 amp use parallel 100 amp CB's to feed the load.

If you were closer I have 4-800 amp and 2-1200 amp I-Line panels with everything from 200-800 amp CB's for temporaries.


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## Shockdoc (Mar 4, 2010)

I did one a few years back, I set up all the equipment, ran out sub feeds, did ckt swaps after hours. I had the building down for about 4 hours while I tied in the new metering eq to the existing UG feeders live. I only had 8 meters out to deal with


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## hardworkingstiff (Jan 22, 2007)

Is the new equipment being installed in the same place as the existing meters? Trying to understand if you can connect to the existing 16 feeders leaving the meterbase. 

I'm assuming the panels are in the tenant space? If so, are the service disconnects outside by the meters? Are they being reused? 

In my mind you have not given enough information for anyone to give good suggestions. If you can explain a little more I'm sure someone can help.


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## Whatsmyname789 (Jul 1, 2009)

*800 amp gear swap*

Thanks guys!! Sorry for the lack of details, but tonight I will have all the photos and details that we all need in order to setup the best solutions to replace the gear while keeping the power on.

From the info that I have got this gear is all outside and the building has 8 tenants and most of the tenants are feed with two meters, at each meter based is fused (breakers) at 100amps 3phase 120/208V each. I'm stepping into this job at the last minute and our other employee total f'd this up big time with the bid to the customer. So I'm here to save the job and get it back on track.


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## Shockdoc (Mar 4, 2010)

AL SER or MC to the rescue as sub feeds, that often helps in a f'd up bid.


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## Whatsmyname789 (Jul 1, 2009)

Here's a picture of the service and the details:

800amp main 2 phase 120/208V 8' Long
2x750MCM AL Main feeders w/ 2x350MCM AL Neutral conductors
16 - 100 amp 3phase main disconnects with 1 1/2" PVC underground feeder w/ #1/1/1/4 to sub main lug sub panels

Whats the smallest most cost effective gear that is 800-1000amp fused rated, with 18 - 200amp rated meter sockets with breaker disconnects.

How would you supply temp power to the units?


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## hardworkingstiff (Jan 22, 2007)

If the new gear is going in the same place as the existing gear, then it seems to me they are going to be without power for a day. You might be able to get them running a little sooner, but I wouldn't suggest it (they will only hear the shorter time and then be upset when you are a little over).

The cost of providing them power while you are working on their feeders seems to be more than it's worth, but the tenants might not agree.

Curious, why is this being changed out?


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## Whatsmyname789 (Jul 1, 2009)

The existing service meter sockets are failing and this site also has another 1200 amp service that feeds another building that also the meter sockets are failing. They have robbed parts from one service to another and now they have some that don't work, and also they want to upgrade a tenant to have an additional 100 amps of service. I was thinking when the new service was installed to re-pulled the feeders to give them 150amps at each panel because now they only have 100 amps at each panel. My hopes are the panels are rated at 150 amps so we won't have to do panel swaps. The conduit feeding these panels are 1 1/2" PVC so it's going to be a tight fit as I think code will only allow 1/0 CU x 3, #1 CU/#4 CU. 

As far as being out of power most of these tenants are restaurants that are open 7 days a week up from 7am - 10pm. The building owner also is signing a new lease with one of the tenants and we have to keep them very happy and also the what if's something doesn't work right we need to have backup power onsite and ready to go. I was thinking of bring in a 200kw generator for temp power. That way we could swap the service over as fast as possible and provide temp power for those who really need it and also have it just as a backup measure.

The existing service is mounted on the ground but over the years the ground has settled quit a bit and now the gear is leaning over. So we will need to pour a new pad or figure out a way to mount the new gear to the wall, but the wall is only 4' high and is made out of concrete block. I thought we could build a uni strut frame and attached it to the wall to mount the new service to. Does this make sense and what would you do? I have to keep the tenants happy per the building owner that is paying for this, typically we would have to have the power company disconnect the secondary's but now I'm leaning towards changing it out hot as I don't want to have to wait on the city electrical inspector and the power company.


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## hardworkingstiff (Jan 22, 2007)

I know you are looking for ideas on how to approach this, but what was the original plan? Your info says you are an electrical contractor. Was this your job to start with or are you coming in after another contractor?

Did you have a plan before you agreed to do the work? If so, what was it?


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## dronai (Apr 11, 2011)

I don't see how you can do it, if you are locating the new in the same spot. Maybe a temp panel with a few mains you could relocate the existing feeders a few feet away, and feed from the generator.


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## sbrn33 (Mar 15, 2007)

I would schedule a Sunday shut down Monday morning start up. If they don't like that see what happens when it blows.
On the other hand I would charge so much to temp these that the only will suggest a Sunday shut down. 
Temping these panel will be next to impossible to do safely and still work around. JMO


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## varmit (Apr 19, 2009)

Since I have no info on space constraints, the method with the least end user down time would be to install the new main services in their entirety. Have the service inspected and powered up and leave the old switchgear powered temporarily from the utility. Then change over the tenant services a few at a time from the old to the new switchgear. Depending on physical space and timing, this could be the least expensive method. The method, that you described, seems to be a scenario that could cause many issues. Any time that you do work where you are absolutely limited on time- something WILL go wrong.


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## sbrn33 (Mar 15, 2007)

If you change that out hot you are crazy. Inspectors and POCO's schedule after hours all the time.


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## macmikeman (Jan 23, 2007)

The best way to pull it off when you are putting the new service into the same location as the original is to provide a one day shut down scenario , and then flood that bugger with enough expert men to pull it off in one day's time. If the landlord say's impossible to force the tenants to go without power for one day, then remind them, that is the same thing that happens when a big storm hits, and this could be also turned into a training type drill for the tenants. Example- have power shut off for one day, so they could test how well they are prepared for just such an event in the case of an unscheduled power failure. Melt the two together to give the tenants a feeling of inclusion. 



Just be careful if employee's of Croft start showing up during your shutdown, and emergency drill combination ..............................:laughing:


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## Cow (Jan 16, 2008)

Can you schedule a shutdown after the restaurants close? If they are worried about their alarms being down, hire a security guard to check businesses while the shutdown is happening. That will be FAR CHEAPER than a gen and the labor to temp power the restaurants. I would think their freezers/reefers should be able to handle the power loss for a few hours without the food warming up too much since no one will be going in and out of them.

If the feeders won't reach the breakers in the new gear have premade pigtails with insulated taps already made up and ready to extend the existing feeders. Set the new gear and shim the low side up so it sits level. I'm thinking you can come back later and have someone form around the gear footprint and use a slurry mix under the gear to level out the sloping concrete. Hopefully your underground conduits stick up a few inches.

The job doesn't look too difficult as long as you can get all your ducks in a row. Finding gear with a similar layout and load terminations in the same spot would be a real timesaver.


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## Whatsmyname789 (Jul 1, 2009)

hardworkingstiff said:


> I know you are looking for ideas on how to approach this, but what was the original plan? Your info says you are an electrical contractor. Was this your job to start with or are you coming in after another contractor?
> 
> Did you have a plan before you agreed to do the work? If so, what was it?


Yes I'm coming in after another electrical contractor dropped the ball big time. No they didn't really have plans, but the plans they had totally sucked. It was basically more a bid/quote that they gave which stated they would provide backup power to the tenants, swap gear during daytime hours, and charge way too much for such little service. The deal breaker was the constant change order before they even started any work.

So now I'm redesign this install to make it go smoothly. The building owners have it in their head that they have to provide backup power and it's in the budget. I don't mind have a generator onsite because of the what ifs and if something happens it's better to spend the money on a rental of a generator then to not be able to restore power if needed.


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## Whatsmyname789 (Jul 1, 2009)

Cow said:


> Can you schedule a shutdown after the restaurants close? If they are worried about their alarms being down, hire a security guard to check businesses while the shutdown is happening. That will be FAR CHEAPER than a gen and the labor to temp power the restaurants. I would think their freezers/reefers should be able to handle the power loss for a few hours without the food warming up too much since no one will be going in and out of them.
> 
> If the feeders won't reach the breakers in the new gear have premade pigtails with insulated taps already made up and ready to extend the existing feeders. Set the new gear and shim the low side up so it sits level. I'm thinking you can come back later and have someone form around the gear footprint and use a slurry mix under the gear to level out the sloping concrete. Hopefully your underground conduits stick up a few inches.
> 
> The job doesn't look too difficult as long as you can get all your ducks in a row. Finding gear with a similar layout and load terminations in the same spot would be a real timesaver.


Thanks I like the idea of having all my pigtails pre-made and ready to go. Yes the conduits do stick up a few inches, but what do you mean by pour a slurry mix? The ground where the gear sits is totally f'd up as it's asphalt, concrete and even have some uni strut smashed into the ground to hold up the gear. I'm going to see if I can mount the gear to the wall so we can cut out all the asphalt and concrete and pour one nice pad and then also we would be able to get a ufer in at that point. They have already made the call that they want a backup generator and it's in the budget and they also have a security guard that we can use to watch the site and the generator so nothing happens. I feel that I can have this switched out in a night, but I want to have a backup plan just in case.


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## hardworkingstiff (Jan 22, 2007)

Whatsmyname789 said:


> Yes I'm coming in after another electrical contractor dropped the ball big time. No they didn't really have plans, but the plans they had totally sucked. It was basically more a bid/quote that they gave which stated they would provide backup power to the tenants, swap gear during daytime hours, and charge way too much for such little service. The deal breaker was the constant change order before they even started any work.
> 
> So now I'm redesign this install to make it go smoothly. The building owners have it in their head that they have to provide backup power and it's in the budget. I don't mind have a generator onsite because of the what ifs and if something happens it's better to spend the money on a rental of a generator then to not be able to restore power if needed.


You still haven't said what your plan was when you put your number in.

How were you planning to provide the temp power to the tenants? Were you going to try to use the existing feeders to the tenants panels? How would you change out the gear if you decided to do it this way? Were you going to run temp feeders to the tenants panels so you would be able to work on the gear w/out having to deal with the existing conductors feeding the tenants panels being hot?

There is going to be down time or a whole lot of work to minimize it. 

I'm going to ask you again, what specifically was your plan when you quoted it? How were you going to get temp power to the tenants panel when you are tearing out the old gear, pouring concrete (if that's what's going to happen) for the new gear, or mounting the new gear to the building?

As you stated, the conduits are not big enough for the 1/0 conductors you wanted to install, so what's the plan there?

It sure seems like you don't have this figured out. How did you bid it?


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## Whatsmyname789 (Jul 1, 2009)

sbrn33 said:


> If you change that out hot you are crazy. Inspectors and POCO's schedule after hours all the time.


Why do you say that? We do hot service changes all the time. Yes I can the power company and inspector do after hours, but when do this they become even more difficult to work with as the power company will not reconnect unless the inspector has signed off so if we have any issues then we are basically screwed. If I do it hot then I can connect it back up when I'm ready and have the inspector come out during the day and it doesn't matter what he says as it will already be energized so we can make corrections if needed rather then being totally dependent on so many other people that out here always seem to have some issue that they want before they sign off. Our inspectors are always so difficult to work with. We are going to have an inspection before we do any of this work or more of a meet and greet/buttering up to see what he might want to see so that way we are already on top of it. Also the building owners already want to have a backup generator onsite and it's in the budget, but I can size down the generator by not having to supply temp power to all the tenants just a few that we will be pulling new feeders to increase their service.

This service has parallel runs of 750mcm AL. All we would do it loosen then up one at a time off the lugs and tape the exposed end of the conductor. Of course we will be careful and safe, but I don't see any reason why this would be an issue. We have all the safety gear to work on 600V and under systems.


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## Going_Commando (Oct 1, 2011)

Whatsmyname789 said:


> Why do you say that? We do hot service changes all the time. Yes I can the power company and inspector do after hours, but when do this they become even more difficult to work with as the power company will not reconnect unless the inspector has signed off so if we have any issues then we are basically screwed. If I do it hot then I can connect it back up when I'm ready and have the inspector come out during the day and it doesn't matter what he says as it will already be energized so we can make corrections if needed rather then being totally dependent on so many other people that out here always seem to have some issue that they want before they sign off. Our inspectors are always so difficult to work with. We are going to have an inspection before we do any of this work or more of a meet and greet/buttering up to see what he might want to see so that way we are already on top of it. Also the building owners already want to have a backup generator onsite and it's in the budget, but I can size down the generator by not having to supply temp power to all the tenants just a few that we will be pulling new feeders to increase their service.
> 
> This service has parallel runs of 750mcm AL. All we would do it loosen then up one at a time off the lugs and tape the exposed end of the conductor. Of course we will be careful and safe, but I don't see any reason why this would be an issue. We have all the safety gear to work on 600V and under systems.


So you are going to just slide 6 - 750s out of lugs, tape them up, remove the switch gear, drop new on top of it easy as can be? It never seems to be that easy and i dont know about you, but 6 energized 750s give me the willies plus you need to cut and strip the ends to have fresh conductor under the lugs. Have fun with that.


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## hardworkingstiff (Jan 22, 2007)

Going_Commando said:


> So you are going to just slide 6 - 750s out of lugs, tape them up, remove the switch gear, drop new on top of it easy as can be? It never seems to be that easy and i dont know about you, but 6 energized 750s give me the willies plus you need to cut and strip the ends to have fresh conductor under the lugs. Have fun with that.


I agree with your assessment. 

I guess he's also going to be wearing all the correct PPE?

IMO, the OP is in over his experience level.


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## circuitman1 (Mar 14, 2013)

i don't see nothing but bad things happening here!look like you could build a new panel & gear next to it after you have poured a pad for it,& stubbed up the necasary conduits. run the primary from the poco to it. then swap the tenants out one by one. then demolish the old one. might have to use a gutter for the splices. this would seem much safer. i place safety first!


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## varmit (Apr 19, 2009)

There are too many "what ifs" to even begin to analyze all of the things that could go wrong with this.

You seem unconcerned about the personal safety aspects. Think about the potential for catastrophic equipment damage. What about the possibility of a wire (or wires) shorting out and burning up a large section of the conductor or the switchgear. What sort of response would you get from the local utility if you blow up their transformer at midnight? What If you were to need to repull part of the service due to damage. Are the existing service conductors even long enough? Will they need to be cut and relugged while energized?

A little more planning and coordination with all of the players in this project would be beneficial to everyone involved.


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## MHElectric (Oct 14, 2011)

hardworkingstiff said:


> IMO, the OP is in over his experience level.



Lets give this guy credit for not being scared to handle a difficult situation. You cant score a goal by playing it safe all the time. This job would be over my head...but, I'd still give it my best shot and try to figure out how to pull it off.

Sometimes taking the bull by the horns shows a man what hes really made of.


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## glen1971 (Oct 10, 2012)

Whatsmyname789 said:


> This service has parallel runs of 750mcm AL. All we would do it loosen then up one at a time off the lugs and tape the exposed end of the conductor. Of course we will be careful and safe, but I don't see any reason why this would be an issue.* We have all the safety gear to work on 600V and under systems*.


At what Arc Flash Rating of the service? If there is no study done, and you do create a fault, I guess we can read about you in the "Workplace Safety" section of the board.... Do you get a bonus for taking such a huge risk with you and/or your employees?? If any of your guys have a clue, they'll exercise "*their right to refuse unsafe work*" and let you do it alone... I know I would...


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## hardworkingstiff (Jan 22, 2007)

varmit said:


> There are too many "what ifs" to even begin to analyze all of the things that could go wrong with this.
> 
> You seem unconcerned about the personal safety aspects. Think about the potential for catastrophic equipment damage. What about the possibility of a wire (or wires) shorting out and burning up a large section of the conductor or the switchgear. What sort of response would you get from the local utility if you blow up their transformer at midnight? What If you were to need to repull part of the service due to damage. Are the existing service conductors even long enough? Will they need to be cut and relugged while energized?
> 
> A little more planning and coordination with all of the players in this project would be beneficial to everyone involved.





MHElectric said:


> Lets give this guy credit for not being scared to handle a difficult situation. You cant score a goal by playing it safe all the time. This job would be over my head...but, I'd still give it my best shot and try to figure out how to pull it off.
> 
> Sometimes taking the bull by the horns shows a man what hes really made of.


Please note, I did not say he was in over his head, just his experience level. This is not a difficult electrical job, just a job that is difficult to keep tenants in power. 

I don't think the OP is thinking it through completely. I know how easy it is to think "we'll figure it out when we get there" because I've done it. I also know this is a job that you want to figure it all out before you start, and I mean all. 

That's what I'm trying to point out. I think the OP can do this job, just that if he's too loose about the planning he will have some difficult times, and I'm a bit concerned that he is too cavalier about safety.

I agree 100% with your statement about planning.


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## Whatsmyname789 (Jul 1, 2009)

hardworkingstiff said:


> You still haven't said what your plan was when you put your number in.
> 
> How were you planning to provide the temp power to the tenants? Were you going to try to use the existing feeders to the tenants panels? How would you change out the gear if you decided to do it this way? Were you going to run temp feeders to the tenants panels so you would be able to work on the gear w/out having to deal with the existing conductors feeding the tenants panels being hot?
> 
> ...


I got thrown in the middle of this job so that is what I'm working out now all the details. I disagree that the 1 1/2" PVC is large enough for 1/0, but ideally not what I would of have installed, but it is what is there already so I have to work with it. As far as temp power we would have a main lug I-Line panel with 100amp breakers feed from a 300kw-600kw generator that would tie into the feeders at the gear. Hopefully we will not need to do all this, but we would still have all the equipment onsite to be safe just in case. All the sub feeds would be out of the way as the new gear comes in 36" sections that we would set into place and bolt together. As far as pouring concrete yes we would have to pour a new pad. I have been thinking about a way to support the current gear off the ground, add rebar & ufer ground, and pour 2000 psi concrete that will setup fast. That way the gear is only temp off the ground for a short period of time. We would have someone one site 24/7 until everything was done. As far as the bid we have a budget we have to work in so that's not a huge issue that is why I'm trying to plan everything now. Yes we would do this hot because the power company is difficult at best and they want to shut down the entire transformer which will effect 35 plus tenants. I don't see an issue if we do it safely as we have all the proper gear and tools to do this. Safety is a concern and we always take that into consideration. We would use most all the existing feeders to the sub panels and do a 2 ton crimp to extend the conductors that are short. The main feed will be long enough so that is not an issue.


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## hardworkingstiff (Jan 22, 2007)

Whatsmyname789 said:


> I got thrown in the middle of this job so that is what I'm working out now all the details. I disagree that the 1 1/2" PVC is large enough for 1/0, but ideally not what I would of have installed, but it is what is there already so I have to work with it. As far as temp power we would have a main lug I-Line panel with 100amp breakers feed from a 300kw-600kw generator that would tie into the feeders at the gear. Hopefully we will not need to do all this, but we would still have all the equipment onsite to be safe just in case. All the sub feeds would be out of the way as the new gear comes in 36" sections that we would set into place and bolt together. As far as pouring concrete yes we would have to pour a new pad. I have been thinking about a way to support the current gear off the ground, add rebar & ufer ground, and pour 2000 psi concrete that will setup fast. That way the gear is only temp off the ground for a short period of time. We would have someone one site 24/7 until everything was done. As far as the bid we have a budget we have to work in so that's not a huge issue that is why I'm trying to plan everything now. Yes we would do this hot because the power company is difficult at best and they want to shut down the entire transformer which will effect 35 plus tenants. I don't see an issue if we do it safely as we have all the proper gear and tools to do this. Safety is a concern and we always take that into consideration. We would use most all the existing feeders to the sub panels and do a 2 ton crimp to extend the conductors that are short. The main feed will be long enough so that is not an issue.


Good luck, let us know how it works out.


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## Whatsmyname789 (Jul 1, 2009)

glen1971 said:


> At what Arc Flash Rating of the service? If there is no study done, and you do create a fault, I guess we can read about you in the "Workplace Safety" section of the board.... Do you get a bonus for taking such a huge risk with you and/or your employees?? If any of your guys have a clue, they'll exercise "*their right to refuse unsafe work*" and let you do it alone... I know I would...


This is feed from a 500Kva 3 phase 208Y R/X=0.2 %Z=2.3 FC=26200A. I don't think this is taking a huge risk by any means. We would use our boom truck to remove the old gear and the same to install the new gear. Sometime you cannot just kill the power to everything and that's why they have gear, tools and equipment to do jobs like this.


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## glen1971 (Oct 10, 2012)

Whatsmyname789 said:


> This is feed from a 500Kva 3 phase 208Y R/X=0.2 %Z=2.3 FC=26200A. I don't think this is taking a huge risk by any means. We would use our boom truck to remove the old gear and the same to install the new gear. Sometime you cannot just kill the power to everything and that's why they have gear, tools and equipment to do jobs like this.


 
I agree that they have the proper tools and gear to do most hot work, but there is also a time and a place to shut down the power and do it safely.. A strip mall would be such a place.. If the utility has to plan outtages for all their customers, I'm sure a mall can handle it. Maybe closing a couple hours earlier and opening a couple hours later might be an option...

Can a hospital Emergency Room take a full power outtage? With the right coordinating and time constraints yes. For days, probably not..
How about a chemical plant where turning off the power would have catostrophic results? Probably not. But I'm sure that they still do PMs and have plans in place to work on their systems live.

In today's age where Arc Flash Hazzards and electrical procedures to mitigate them are being more and more scrutinized and fewer people are willing to accept the risks of signing the Energized Electrical permit should something go sideways, we are being forced to do less and less work with the power on.. I'm not saying the hazzards are greater than they were 10 years ago, but the awareness and penalties for them sure is.. 
I know I don't want to be the guy on the otherside of an inquiry saying "We did it live to keep Company X open later. I'm sorry Bob is in the burn unit..."


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## Cow (Jan 16, 2008)

It only takes one anonymous phone call to OSHA while you're playing with hot service entrance wiring and you'll wish you would of just killed power to those tenants....

Over here I'd have the utility kill the transformer, pull the leads (at the transformer) feeding the switchgear loose and reenergize the transformer. Then reverse the procedure for when the new gear was installed.


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## pete87 (Oct 22, 2012)

MHElectric said:


> Lets give this guy credit for not being scared to handle a difficult situation. You cant score a goal by playing it safe all the time. This job would be over my head...but, I'd still give it my best shot and try to figure out how to pull it off.
> 
> Sometimes taking the bull by the horns shows a man what hes really made of.





Depends where you " Take The Horns "


pete87


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## hardworkingstiff (Jan 22, 2007)

Whatsmyname789 said:


> As far as temp power we would have a main lug I-Line panel with 100amp breakers feed from a 300kw-600kw generator that would tie into the feeders at the gear. Hopefully we will not need to do all this, but we would still have all the equipment onsite to be safe just in case. * All the sub feeds would be out of the way *as the new gear comes in 36" sections that we would set into place and bolt together. As far as pouring concrete yes we would have to pour a new pad.


OK, this is what I understood you to say. You are going to feed the existing tenants with temp power when you disconnect the feeder from the existing disconnect (in the MDP). 

Based on this understanding, how are you going to get the old gear out and the new gear in with the existing feeders being tied to temp conductors? I'm assuming the conduits with the existing feeders to the tenants panel are coming into the bottom of the gear enclosure. Is that assumption incorrect?


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