Connecting things to an already near full panel

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swimmer_spe

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Picture this:
2 bedroom home.
200 amp service.
Less than 10 spots left in the panel.

We plan on doing an addition that will include a bedroom and bathroom. We also plan on building a garage.

Part of me thinks that I need an electrician to come in and combine some circuits to clear up some space in the panel.
 

Eddie_T

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Picture this:
2 bedroom home.
200 amp service.
Less than 10 spots left in the panel.

We plan on doing an addition that will include a bedroom and bathroom. We also plan on building a garage.

Part of me thinks that I need an electrician to come in and combine some circuits to clear up some space in the panel.
If the panel doesn't already have tandem breakers that might be an option to consider. Depending on how you plan to use the garage you might consider adding a panel for it.
 

swimmer_spe

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If the panel doesn't already have tandem breakers that might be an option to consider. Depending on how you plan to use the garage you might consider adding a panel for it.
It has some.
I figure I need 60-100 amps for the garage if I build it out as I plan.
 

bud16415

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I have a 100a panel for the garage and it is way more than i need but is nice to know I have it. With just me using it about my biggest load would be the compressor running and me welding with a lot of lights on. They are all LED now so even that wouldn't be much. Now if I buy an EV that could change things.
 

afjes_2016

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swimmer-spe

You really are not giving us much to go on. 200amp service seems good for the size house you have. Even with an addition being added even with the garage. That is unless you plan on having some power hungry things in the garage and adding power hungry things in the house like a hot tub etc.

Limited space in your panel is not an obstacle. If tandems are not allowed or rated for your panel a sub panel installed next to the panel can increase the number of circuits. Also, running a sub panel out to your garage is not a big deal. If the garage will be detached you can only run one line out there so be sure it is big enough to run the things you want to in the garage.

What electrical appliances do you have in the home so far?

I don't recall you skill level but I know I have seen posts from you on this forum. Adding a sub panel to your existing panel is not really a big deal. If you are comfortable working with the electrical system you can do it even. Then run all your new circuits from the sub panel.

If you have 10 spaces left in your existing panel you can use 4 full spaces for two 2 pole breakers one each to power the garage sub panel and one to power the sub panel to power the new addition. You will still have a few left over in the main panel.

If you give us a bit more details we can help you.
 

ajaynejr

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Six gauge (copper) wiring to the subpanel is rated 55 amps but you may put a 60 amp breaker (round up to the next stock size) in the supra panel. Two gauge wiring is rated for 95 amps and you may use a 100 amp breaker. But if your subpanel load analyses (sample rules at the back of the NEC code book) come out to 60 or 100 amps you would need heavier feed wires than quoted here.

For your addition or for an attached garage, if your crystal ball gave you bad advice and you needed more power than you strung subpanel feeder cables for then you could always install a (another) subpanel under your existing panel and run more individual branch circuits.

Technically you should do (or your inspector may require) a whole house load analysis for a project this size although I think (my gut feeling is) your 200 amp service is plenty enough power.
 

swimmer_spe

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I have a 100a panel for the garage and it is way more than i need but is nice to know I have it. With just me using it about my biggest load would be the compressor running and me welding with a lot of lights on. They are all LED now so even that wouldn't be much. Now if I buy an EV that could change things.
Since this is our "forever home", I want to make sure when we both own the latest EVs, we can put a charger in that would charge all our EVs.

swimmer-spe

You really are not giving us much to go on. 200amp service seems good for the size house you have. Even with an addition being added even with the garage. That is unless you plan on having some power hungry things in the garage and adding power hungry things in the house like a hot tub etc.

Limited space in your panel is not an obstacle. If tandems are not allowed or rated for your panel a sub panel installed next to the panel can increase the number of circuits. Also, running a sub panel out to your garage is not a big deal. If the garage will be detached you can only run one line out there so be sure it is big enough to run the things you want to in the garage.

What electrical appliances do you have in the home so far?

I don't recall you skill level but I know I have seen posts from you on this forum. Adding a sub panel to your existing panel is not really a big deal. If you are comfortable working with the electrical system you can do it even. Then run all your new circuits from the sub panel.

If you have 10 spaces left in your existing panel you can use 4 full spaces for two 2 pole breakers one each to power the garage sub panel and one to power the sub panel to power the new addition. You will still have a few left over in the main panel.

If you give us a bit more details we can help you.
I would be hiring an electrician, ans I have the general rule of never opening a panel. I will wire something into a circuit, or replace most anything, but messing with 240V that is live somewhere there is not something I want to do. W already have the wiring for a hot tub, but there isn't one right now. We plan to get one before getting the garage. outside of that, no real difference than a modern home. We have a dishwasher, a heat pump, electric stove(which will eventually be swapped out to propane), clothes dryer, etc.

Six gauge (copper) wiring to the subpanel is rated 55 amps but you may put a 60 amp breaker (round up to the next stock size) in the supra panel. Two gauge wiring is rated for 95 amps and you may use a 100 amp breaker. But if your subpanel load analyses (sample rules at the back of the NEC code book) come out to 60 or 100 amps you would need heavier feed wires than quoted here.

For your addition or for an attached garage, if your crystal ball gave you bad advice and you needed more power than you strung subpanel feeder cables for then you could always install a (another) subpanel under your existing panel and run more individual branch circuits.

Technically you should do (or your inspector may require) a whole house load analysis for a project this size although I think (my gut feeling is) your 200 amp service is plenty enough power.
I thought that sub panels had to have a breaker on the main panel. If not, then I am good. I do plan to have a separate panel in the garage. I'd prpbably go 100amp to ensure I have all the available power I need.
 

ajaynejr

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Yes, a subpanel needs a breaker in the panel feeding it.

Each separate building or structure (including the main house itself) needs a master breaker, usually located at the top of the first panel in that building.

An ordinary on-off switch (double pole for a 120/240 volt or 240 volt only feed) can be the building master if the electrical load is small enough not to need a subpanel in that building.

When you do not want to ever open a panel, it is least confusing to have your electrician install the first outlet box (or each subpanel itself) for each new branch circuit you want installed. Including branch circuits out of a subpanel because (almost always) each subpanel is going to have 240 volts in it. Otherwise there is the risk of miscommunication where the electrician installs the cable but it is too short at the far end hanging loose for you to finish..
 
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afjes_2016

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swimmer-spe
I thought that sub panels had to have a breaker on the main panel. If not, then I am good.
A sub panel must be fed by something and that is from the main panel (or even another sub panel) and in the panel feeding it a 2 pole breaker. 2 hots, one neutral and a ground to the sub.

One thing you may want to consider which may end up being cheaper and more cost worthy in the end. Since you plan on having a few EV chargers going at one time. If your garage is not that far from the utility pole you may want to have the PoCo install a separate meter at the garage with its own power. Then you won't have to run a line from the house to the garage and the main panel in the house will just service the house itself. You seem to have a lot on the service already. Especially with the hot tub (which you will more than likely put into use soon) and you have the heat pump. Even though you are changing your stove to gas.

The separate service will cost you each month but with that cost and the cost of the panel installation in the garage which you would have to do anyway this may be a better option for you to at least consider. We don't know how far the garage is from the house. Just the cost of the line from the house to the garage and the trenching cost could out weigh the cost of the new service.
 

68bucks

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swimmer-spe


A sub panel must be fed by something and that is from the main panel (or even another sub panel) and in the panel feeding it a 2 pole breaker. 2 hots, one neutral and a ground to the sub.

One thing you may want to consider which may end up being cheaper and more cost worthy in the end. Since you plan on having a few EV chargers going at one time. If your garage is not that far from the utility pole you may want to have the PoCo install a separate meter at the garage with its own power. Then you won't have to run a line from the house to the garage and the main panel in the house will just service the house itself. You seem to have a lot on the service already. Especially with the hot tub (which you will more than likely put into use soon) and you have the heat pump. Even though you are changing your stove to gas.

The separate service will cost you each month but with that cost and the cost of the panel installation in the garage which you would have to do anyway this may be a better option for you to at least consider. We don't know how far the garage is from the house. Just the cost of the line from the house to the garage and the trenching cost could out weigh the cost of the new service.
I wanted to run my barn with a separate feed and meter. It would have been a much shorter, easier run and my house pan is pretty full. The power company told me the minimum monthly billing is $50 and there wouldn't be many times I would use that so I ran it from the house.
 

swimmer_spe

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swimmer-spe


A sub panel must be fed by something and that is from the main panel (or even another sub panel) and in the panel feeding it a 2 pole breaker. 2 hots, one neutral and a ground to the sub.

One thing you may want to consider which may end up being cheaper and more cost worthy in the end. Since you plan on having a few EV chargers going at one time. If your garage is not that far from the utility pole you may want to have the PoCo install a separate meter at the garage with its own power. Then you won't have to run a line from the house to the garage and the main panel in the house will just service the house itself. You seem to have a lot on the service already. Especially with the hot tub (which you will more than likely put into use soon) and you have the heat pump. Even though you are changing your stove to gas.

The separate service will cost you each month but with that cost and the cost of the panel installation in the garage which you would have to do anyway this may be a better option for you to at least consider. We don't know how far the garage is from the house. Just the cost of the line from the house to the garage and the trenching cost could out weigh the cost of the new service.
The pole would be within 10 feet of the new garage. The house is about 50 feet away. Having it's own meter is something I have thought of doing.
 

afjes_2016

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swimmer-spe

What I suggest that you do is a load calculation on your own. Do this before you make a final decision on either feeding the new garage or/and the extra power needed for the addition.

Doing this load calculation will give you a bit more clarity on how much power you will need and how much extra power you should have. Negate the option of either running the garage from the house main panel or a new service just for the garage. The load calculator does not take into consideration that fact. The load calculator will just let you know what will be needed overall. There are a lot of load calculators on the Internet. Find one that is easy to use and understand. They all perform the same function but some are more user friendly for DIYers. Here is one to start with. Learn what VAs are compared to Watts. Understand the basics of Ohms Law so you can input the proper information. If something does not have the watts listed on it then take your volts times you amps that would be listed on the item. If the item has its volts and the watts then to find the amps you would take the watts and divide it by the volts. You don't have to do this with all your appliances but the bigger ones. Heat pump, hot tub, dryer, hot water heater any large appliances in the garage such as your EV charging stations etc. Also figure how much power you want for your addition. Yes, the bathroom may only require one 20amp circuit by code but you may want more than one circuit going to the bathroom. Example: your wife uses a curling iron. It has to heat up; while it heats you decide to use the blow dryer for your hair - there goes the breaker. You want to install a ceiling heater/fan/light unit, that will require a separate circuit. Running a few circuits to the bathroom will help you with this. Your new bedroom - may want a window AC. Run a separate circuit just for that. Running a window AC and a vacuum cleaner on the same circuit will more than likely trip the breaker.

I am not attempting to complicate your decision - I am attempting to ask you to educate yourself - read this as example. Don't rely strictly on someone else's word as to how much power you will need compared to what you have and what you may want in the future since this is your permanent home. This way when you speak with your electrician you can have a visual picture of what you need.
 

swimmer_spe

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swimmer-spe

What I suggest that you do is a load calculation on your own. Do this before you make a final decision on either feeding the new garage or/and the extra power needed for the addition.

Doing this load calculation will give you a bit more clarity on how much power you will need and how much extra power you should have. Negate the option of either running the garage from the house main panel or a new service just for the garage. The load calculator does not take into consideration that fact. The load calculator will just let you know what will be needed overall. There are a lot of load calculators on the Internet. Find one that is easy to use and understand. They all perform the same function but some are more user friendly for DIYers. Here is one to start with. Learn what VAs are compared to Watts. Understand the basics of Ohms Law so you can input the proper information. If something does not have the watts listed on it then take your volts times you amps that would be listed on the item. If the item has its volts and the watts then to find the amps you would take the watts and divide it by the volts. You don't have to do this with all your appliances but the bigger ones. Heat pump, hot tub, dryer, hot water heater any large appliances in the garage such as your EV charging stations etc. Also figure how much power you want for your addition. Yes, the bathroom may only require one 20amp circuit by code but you may want more than one circuit going to the bathroom. Example: your wife uses a curling iron. It has to heat up; while it heats you decide to use the blow dryer for your hair - there goes the breaker. You want to install a ceiling heater/fan/light unit, that will require a separate circuit. Running a few circuits to the bathroom will help you with this. Your new bedroom - may want a window AC. Run a separate circuit just for that. Running a window AC and a vacuum cleaner on the same circuit will more than likely trip the breaker.

I am not attempting to complicate your decision - I am attempting to ask you to educate yourself - read this as example. Don't rely strictly on someone else's word as to how much power you will need compared to what you have and what you may want in the future since this is your permanent home. This way when you speak with your electrician you can have a visual picture of what you need.
Not sure why I need a window AC unit when I already have a heat pump. I don't feel there will be any major loads in the addition. Where the major loads will be is in the garage.
 

Eddie_T

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I would prolly just wing it with a subpanel in the garage fed by a 100 amp breaker in the main panel.
 

Sparky617

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You should probably count on having enough for a 50amp EV circuit in your garage. You may not have an EV yet, but if this is your forever home, you probably will in the next ten years. Adding a 100 amp sub panel to the garage might be a good idea. The EV could be charged when you're not doing other power hungry activities like running stationary power tools.
 

afjes_2016

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Not sure why I need a window AC unit when I already have a heat pump. I don't feel there will be any major loads in the addition. Where the major loads will be is in the garage.
I was just trying to give you examples of why you may want to run a few more circuits to the addition - I don't know what your needs are but you do. I just figured that maybe a separate service to the garage would give you more flexibility in both the garage and the addition. Again, the cost of the separate service to the garage may be in the end cheaper than running a line to the garage from the house. Just giving you options. Some home owners don't know that they can do this.
 

ajaynejr

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If your heat pump does not have a reverse mode for room cooling then you will need a separate air conditioner unit if you need cooling. But your load calculation should figure that you don't turn both of them on at the same time.
 

swimmer_spe

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If your heat pump does not have a reverse mode for room cooling then you will need a separate air conditioner unit if you need cooling. But your load calculation should figure that you don't turn both of them on at the same time.
It does. We had no AC in the house. It wasn't much more for a heat pump, and so we went with it.
 

Eddie_T

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Yeah, a heat pump is an AC with a reversing valve. They are usually whole house but now mini-splits and PTAC (PTHP).
 
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