200 amp panel with 100 amp service

[madstat]

I'm replacing the 100 amp panel in my house and I want to upgrade my panel to 200 amp but the actual 100 amp service from the PoCo will not be upgraded for some time (~ 1 year). Is it OK to have a 200 amp panel running off of a 100 amp service?

 

[sberry]

I would say technically no although some of the wiring they allow from the poco these days is pitiful for 200. In a garage where this feed might be coming from an existing service with 100A breaker ahead of it would be fine, the 200 is a simple disconnect switch at this point. Only way I could see an inspector ok'ing this with the idea that the poco will upgrade is if this was a calculated load or even back feed a 100 on to the panel for the time being? No need to quote me on any of this though, its pure speculation.

 

[Gary S]

Ask your power company if they will accept it that way.
Many years ago I owned a house that had 100amp service and a 100 amp panel. I needed to upgrade it so I had an electrician put in a 150amp panel and new wiring from the meter. The power company came out to shut down power for the switchover and I asked them if they needed to upgrade the 100amp wiring to the meter. They didn't feel it was necessary, so the 100amp wire stayed in place connected to their meter even though the 150amp box has a 150amp main breaker.
I suspect that if I wanted 200amp service, they would have changed the wire to something larger.

 

[awdblazer]

the 200 amp main breaker in your panel only protects what is after it (ie the bus) the wiring before your main breaker will be fused at the transformer

 

[pattenp]

Okay.. I don't know much about fusing at the transformers but this just does not seem right. I just can't see how pulling 200A through a 100A service entrance cable is going to trip the fuse back at the transformer before the SE wiring melts.

the 200 amp main breaker in your panel only protects what is after it (ie the bus) the wiring before your main breaker will be fused at the transformer

 

[Lotek]

Okay.. I don't know much about fusing at the transformers but this just does not seem right. I just can't see how pulling 200A through a 100A service entrance cable is going to trip the fuse back at the transformer before the SE wiring melts.

You will still be limited to 100a until the drop is changed, when I relocated and upgraded to a 200a panel, Edison told me I had to show that I had enough of a draw to justify them upgrading the wire, the panel made no difference.

 

[Stuart in MN]

Put a 100 amp main breaker in the panel and you'll be all right. Then, if you do upgrade the service at some point in the future all you have to do is replace the 100 amp main breaker with a 200 amp main breaker. Remember that the upgrade will most likely also require a new meter socket and meter if and when that happens.

 

[RCStocker]

Call your power company and have them check the wiring to your house.
Most homes already have heavey enough wiring to run a 200 amp box. I know most homes built 35 years ago had 100 am boxes. Many have been up graded to 200 amps because of pools and other uses. The wiring to the homes has always been large enough to run the 200 amp boxes. If the wires to your home are underground it will be a 98 percent bet that it will not need to be change.

Just call the company to see what is needed. Who told you that it would be a year before it would be changed? I can't fathem the company saying that. They never change anything until needed or comes down by acts of nature.

If you have over head lines to your box and they are not large enough all they will need to do is run new wires to your house form the pole. They charge for that and you can have that done anytime.

I have had many boxes changed when I have remodeled homes. Seldom do they need to change the lines.

If you are not happy with who you talk to at the power company talk to someone else. They don't always know what they are doing in the office. Any line man can tell you. If you see an Edison truck in your area ask them. They might come and take a look to tell you. I have done that in the past.

If the line is not large enough they will not give you a permit to change over. If you file for a permit and change they will set up a time to turn off the power and change the lines.
A year does not sound right to me.

It is really no big deal. It is not hard to change boxes. You might need to put ground fault
breakers in for the kitchen, bathroom and laundry. Depending on what your local bulding departments require but they are code now.

 

[sberry]

the 200 amp main breaker in your panel only protects what is after it (ie the bus) the wiring before your main breaker will be fused at the transformer

In some cases it protects the wire ahead of it as in a service entrance, there is no wire between the breakers and the branch circuit breakers, it is to limit the load ahead of the breaker in this case.

One of our guys here can probably tell us what kind of fusing they have at the ****** but its not uncommon to see several services connected to one. A dead short would probably blow it but doubt it will go down on basic over current situation.

I just can't see how pulling 200A through a 100A service entrance cable is going to trip the fuse back at the transformer before the SE wiring melts.

Yes, thats why code calls for specific wire for entrance, a wire they know will not overheat before a breaker trips.

 

[theoldwizard1]

Ask your power company if they will accept it that way.

Why would the power company care ? Anything installed by a certified electrician after the meter is not their problem.


The best solution is a panel with changeable mains. Not all panels are made that way, so be sure to ask before you buy it.

 

[wyliesdiesels]

The 200 amp main breaker in your panel only protects what is after it (Ie. the bus). The wiring before your main breaker will be fused at the transformer.

Yeah, people often forget that a breaker protects what's connected to its load side not before it on the line side.

However, transformer fusing is rated for the transformer size and will not be rated for and protect the wire in service drops especially if the transformer feeds and is rated for the load of several homes. But this is a moot point since a home can't even pull more than its main breaker rating.

As far as being ok, u need to talk to your POCO and check several things-
1)make sure the meter is rated for the service size by looking for the letters
TA on the meter. Next to TA will either be 15 or 30. 15 is for 100 amps and 30 is for 200.
2) The wire in your service riser needs to be rated for 200 amps so u need to check the gauge of the wire.

The service drop should also be rated for 200amps but is not your responsibility. However, I have seen many service drops that are undersized but since they are freeair undersizing is not as much of a concern and many POCOs don't care! Some POCOs also don't seem to care about proper transformer sizing judging by the # of burnt/leaking cans I have seen up on poles!

 

[sberry]

Edison told me I had to show that I had enough of a draw to justify them upgrading the wire, the panel made no difference.

Yes, I am adding central air, a hot tub and a pottery kiln next week,,, ha

 

[sberry]

Yeah, people often forget that a breaker protects what's connected to its load side not before it on the line side.

In the case of a service its not, its sized to protect the wiring ahead of it. This is a very basic principle found in a lot of wiring, the wire protected by the calculated connected load, somewhat similar to a light fixture, allows number 16 wire to be connected to circuit with a 20A breaker. Wire is protected due to the fact the fixture has Edison base, only so much load can be applied, wire is big enough to provide short circuit interruption.

 

[madstat]

... Who told you that it would be a year before it would be changed? I can't fathem the company saying that. They never change anything until needed or comes down by acts of nature.

A year is the time-frame I set up for myself to get some work done on my garage. My Idea is to relocate my drop from the back of my house to the back of my detached garage, then using s feed-through panel, run a feeder to a new 200 amp panel in the house. I already called the PoCo and the relocation of the drop to the garage FREE as long as I'm upgrading my service (to 200amp). The thing is that its going to take me awhile to get the garage ready to do this since its really in bad shape and I want to correct some structural issues. I'm doing all the work on weekends by myself and I see this taking a while (~ 1 yr?). In the mean-time the panel in my house is in serious need of a changeout. I want to hire an electrician to upgrade my panel in the house, because currently its a bloated mess. But if we upgrade the service to 200 amps now then the PoCo will charge me for the relocation. So I was just seeing if it was possible for an electrician the put the correct size panel in my house ahead of time so that it doesn't need to be switched out later.

You may ask: why not just upgrade the drop now and run a sub panel from the main in the house to the garage later? Well 2 things:

1) The current drop is running over my neighbor's yard - many times this is not a big deal but technically this is called an "aerial trespass" and the neighbor at any time could call the PoCo and make them move it, necessitating a move anyway. Relocating the drop to my garage is an easy solution.

2) We have a great large back yard and a small house (which we like) but we currently have no back door and are really disconnected from our backyard. We want to put a small addition and deck off the back of our house but where we want to put it is exactly where the current drop is.

Best
Madstat

 

[Falcon67]

FWIW - I upped our panel at the old house to 150 from a "collection" of Federal Pacific boxes. Like - 4 of them. POCO came to re-hook the service and was like "eh, good enough". So no new air drop.

We lived the entire time at that house with the neighbor's drop running across our back yard. It blocked many a field goal kick LOL. POCO offered to move it, then looked around and quoted An Officer and a Gentleman saying "we've go nowhere else to go." No poles anywhere close.

 

[madstat]

The PoCo says in cases where its needed they install some piece of hardware called a "midspan". Properties like mine that have no pole to drop from require them where aerial trespasses are a concern. I have no idea what they look like but apparently that's what they would do if necessary. I'm guessing its some kind of hardware attached to the lines midspan to run a drop from.

 

[MrMark]

You will still be limited to 100a until the drop is changed, when I relocated and upgraded to a 200a panel, Edison told me I had to show that I had enough of a draw to justify them upgrading the wire, the panel made no difference.

Same here. They are not going to change any wire the drop or feeder unless you show via billing that you need the upgrade. They could care less what size panel you put in your house.

 

[MrMark]

Call your power company and have them check the wiring to your house.
Most homes already have heavey enough wiring to run a 200 amp box. I know most homes built 35 years ago had 100 am boxes. Many have been up graded to 200 amps because of pools and other uses. The wiring to the homes has always been large enough to run the 200 amp boxes. If the wires to your home are underground it will be a 98 percent bet that it will not need to be change.

Just call the company to see what is needed. Who told you that it would be a year before it would be changed? I can't fathem the company saying that. They never change anything until needed or comes down by acts of nature.

If you have over head lines to your box and they are not large enough all they will need to do is run new wires to your house form the pole. They charge for that and you can have that done anytime.

I have had many boxes changed when I have remodeled homes. Seldom do they need to change the lines.

If you are not happy with who you talk to at the power company talk to someone else. They don't always know what they are doing in the office. Any line man can tell you. If you see an Edison truck in your area ask them. They might come and take a look to tell you. I have done that in the past.

If the line is not large enough they will not give you a permit to change over. If you file for a permit and change they will set up a time to turn off the power and change the lines.
A year does not sound right to me.

It is really no big deal. It is not hard to change boxes. You might need to put ground fault
breakers in for the kitchen, bathroom and laundry. Depending on what your local bulding departments require but they are code now.

This is mostly false at least in So Cal. Edison ran all the old neighborhoods, from the 70's with underground direct burial feeder at #2 AL, which is sized exactly for what the service was -- 100 amps.

 

[Gary S]

Why would the power company care ? Anything installed by a certified electrician after the meter is not their problem.


The best solution is a panel with changeable mains. Not all panels are made that way, so be sure to ask before you buy it.

The power company cares because if you overload their system and blow their fuse, they get to come out on their dime and fix it. If your power company is proactive, they care about making their system work with a minimum of nuisance calls.

You do not need to waste your money on changing main breakers if you clear it with your power company first and getting it right the first time instead of doing it wrong, doing it halfway, and doing it over numerous times.

 

[Jarcese]

Around here part of the permit process is the fee to the utility for the upgrade. Some times it gets done in a timely manner(3 weeks or so), some times not. The time difference mostly has to do with the lack of workers as minor service work is slightly above street light work on the totem pole.

More often than not you will see electricians try to skirt the fee(somewhere between $300 to $600 for residential) and that old #6 copper service will sit there and feed a 200 amp service forever because you would rarely use all your available amperage.

I have also been out to a few jobs where they were having flickering lights on a new panel upgrade because they upgraded significantly without notifying us for the larger wire.
I always run a new #2 al service(200 amp wire size for us) because nobody wants to hear about their electrician not doing the correct paperwork. It's easier to just do it and forget about fees to keep people happy.

That may be a way for you to get your new service faster. Call in for flickering lights once your side is done. Most guys around here will do it because it's not hard and it's technically an emergency(we don't like burned out equipment) and no longer has has anything to do with sales.

 

[Jarcese]

Also, it is highly unlikely to blow the fuse on the primary side as it is fused for time and current. You have to be over the current of the fuse for a certain amount of time for it to blow(Both K fuses and Time fuses). It's on a curve where high current blows right away and small over current will have to stay over the rating for a period of time. Connections, then wire, then fuses are usually the order of damage that overload does to the circuit. The fuse is really only to protect the transformer, not anything in between. A breaker on a transformer is a different story.

 

[Aceman]

I'm replacing the 100 amp panel in my house and I want to upgrade my panel to 200 amp but the actual 100 amp service from the PoCo will not be upgraded for some time (~ 1 year). Is it OK to have a 200 amp panel running off of a 100 amp service?

Is it not possible to save up and do it all at once? It's usually not a whole lot more work to change the meterbase and mast(assuming it's overhead) all at the same time.

Turning this one job into two seperate smaller jobs, means two seperate power co. disconnects, double the travel charges, getting the tools out twice. It's definitely going to cost more than doing it all at once.