Meter Center Upgrade - Live work

[designer82]

A 40 unit multi-family condo building is looking to increase elec. capacity.

I'm not totally clear on what exactly they're looking to do but it sounded like the service to each dwelling unit has become undersized.
They want to add larger loads within the units, they mentioned electric heat pumps etc.

They also mentioned they want to add EV chargers, so I'll assume they want to also upsize their house panel as well.

1) Assuming a whole new meter center, demo/replace with new feeds to each dwelling unit & house panel. That's a huge amount of work obviously.
That kind of work cannot be done live and would need power shutoff to all building. Please give me a sanity check here to make sure I'm not overlooking anything.

2) If it ends up being less intensive, for example assume the feed to each unit is adequate & main service is adequate but the meter/breaker to each unit at the meter center just needs to be upsized. Could this be done live?

I ask because apparently they had some contractors tell them it can be done live & some tell them it can't be done live.
They don't want the tenants to lose power during the upgrades.

Thanks

 

[electrofelon]

I think you will get different answers on what can be done live or not. There are multiple reasons, such as not everyone being subject to OSHA rules, and not everyone following them.

Lots of variables. If possible, the way to do it is install the new meter center and then you can switch feeders over one at a time. IF there isnt enough physical space to do this, then it certainly gets a lot more difficult.

If just a meter center breaker needs to be changed to a larger one (and it can take a larger one), whether that can be done live might depend on if the breakers are the same frame size, or the bus fingers need to be changed.

 

[hillbilly1]

With that type of job, unless they want to put all of the tenants in temporary housing, a new service will need to be built, either across from, or near the existing service, then transfer the old services over in stages. Then the old service is removed. Since they are adding larger loads in each unit, will the feeds also be upgraded? Conduit or cable? I’ve done this with apartments. Because the electrical room wasn’t large enough, I put the new service outside with all new 3r gear. Piped back in and intercepted the existing feeds.

 

[electrofelon]

With that type of job, unless they want to put all of the tenants in temporary housing, a new service will need to be built, either across from, or near the existing service, then transfer the old services over in stages. Then the old service is removed. Since they are adding larger loads in each unit, will the feeds also be upgraded? Conduit or cable? I’ve done this with apartments. Because the electrical room wasn’t large enough, I put the new service outside with all new 3r gear. Piped back in and intercepted the existing feeds.

Only other thing I can think of is install a big temporary bussed gutter or something nearby and move the feeders over to that one by one, replace meter center, then move the feeders back.

 

[designer82]

Thanks for your replies. It's evident that what can or cannot be done live will certainly depend on the actual scope of the work.

I was thinking along those lines as well, install all the new equipment adjacant to or as close to the existing as possible to allow the minimum power interruption possible.

Even if the unit feeds are undersized, could possibly run parallel feeds live and make connections once everything is installed and ready for minimal power interruption.