Electrical Service Question

[twiggles]

Hello,

I do not know a whole lot about electrical systems, so please bear with me on this question.

Here is the scenario: I have a 200A service in my house. From that, I have a 100A subpanel that is for my basement entertainment area, etc. This leaves me with 100A for the rest of the house. Currently, I have a 20A single breaker for the garage.

Since my house 200A service is pretty maxed out, what is the most cost effective and correct way to get more power to my garage? I'd like a 100A service there as well.

Attached garage, if my home were a clock face, electrical service comes in the basement at 10 o'clock, garage is at 4 o'clock (of course its at the other end of the house...why would anyone want to make this easy and cheap for me?!?!? )

I'd love to hear my options and ballpark cost estimates from some of you guys who know more about this than me. I'm handy, but leave electricity to the pros. I am using this as a gut check so I know what to expect when I decide to bring a pro in for an estimate/recommendations. Thanks in advance.

 

[Steevo]

What do you mean by "pretty maxed out"?
Are all of your breaker slots filled in the main panel?
If not, there is no reason you can't run another 100A remote panel off of it.

 

[pattenp]

The max load is not a matter of just adding up the breakers. Not everything in the whole house will be on at the same time. It's most likely not a problem if you add a sub-panel in your garage. My 200A panel has a total of 725A of breakers. Why do you feel you need 100A for the garage?

 

[twiggles]

What do you mean by "pretty maxed out"?
Are all of your breaker slots filled in the main panel?
If not, there is no reason you can't run another 100A remote panel off of it.

Yes, all breaker slots are full...

 

[pattenp]

Can your main panel use half size breakers to free up space?

Does the sub-panel in the basement have space?

 

[twiggles]

The max load is not a matter of just adding up the breakers. Not everything in the whole house will be on at the same time. It most likely is not a problem if you add a sub-panel in your garage. My 200A panel has a total of 725A of breakers. Why do you feel you need 100A for the garage?

I have a lift in the garage, lathe, table saw, compressor, etc. Its gets dicey when I am running dust collection along with some of the other tools. I would love to be able to add electric heat and other 220 items in the garage (larger compressor, etc).

The main concern I have with the 100A service for my living area is that it supports 2 A/C units and an electric dryer among everything else in a home. The AC units and dryer can all run simultaneously. Add to this a table saw start-up and dust collection and you have some serious draw.

Am I not thinking about this the right way?

 

[ishiboo]

Hint: if it has 40 spaces, you probably can't add any tandems. If it's a 30, you may be able to get up to 40 circuits.

 

[Falcon67]

I believe you are overthinking it. I have a 200A panel on a 1600 sq/ft house with 100A off to a 960 sq/ft shop. The house has 3.5 tons of AC and electric heat at about 9500w. 50 gallon electric water heater, electric dryer (no NG in this neighborhood). Plus all the other stuff - stove, etc. Shop has 5000w heater, two AC units (total 17K BTU) welder, drill press, metal saw, lathe, band saw, miter saw, 240V mill, 240V 3.5HP compressor, lots of lights and all the usual hand power tools. I also have a table saw but don't use it much so it stays stored.

No trips, ever.

 

[twiggles]

Can your main panel use half size breakers to free up space?

Does the sub-panel in the basement have space?

Hint: if it has 40 spaces, you probably can't add any tandems. If it's a 30, you may be able to get up to 40 circuits.

I will take a picture tonight and post. Unfortunately, I think All is pretty full on the sub panel as well. I know the main panel is large, I would have to confirm whether 30 or 40 spaces.

I appreciate all of the help and clarifying questions thus far!

 

[Falcon67]

I had the same issue - full panel. The meter box was falling off the house, so when the local co-op utility came out to fix that I had them put a 100A 6 space panel for the jump to the shop right off the meter base. Your utility may think differently, but for mine it was no problem.

 

[pattenp]

I have a lift in the garage, lathe, table saw, compressor, etc. Its gets dicey when I am running dust collection along with some of the other tools. I would love to be able to add electric heat and other 220 items in the garage (larger compressor, etc).

The main concern I have with the 100A service for my living area is that it supports 2 A/C units and an electric dryer among everything else in a home. The AC units and dryer can all run simultaneously. Add to this a table saw start-up and dust collection and you have some serious draw.

Am I not thinking about this the right way?

I have everything that you mention and have never had a problem with power. I have an attached garage and a detached garage both served with 60A sub-panels. I'm a one man use only so at most I have a 5000W heater, 10A table saw and a 7A dust collector running at once. Oh and a radio and a few amps of overhead lighting.

 

[twiggles]

I believe you are overthinking it. I have a 200A panel on a 1600 sq/ft house with 100A off to a 960 sq/ft shop. The house has 3.5 tons of AC and electric heat at about 9500w. 50 gallon electric water heater, electric dryer (no NG in this neighborhood). Plus all the other stuff - stove, etc. Shop has 5000w heater, two AC units (total 17K BTU) welder, drill press, metal saw, lathe, band saw, miter saw, 240V mill, 240V 3.5HP compressor, lots of lights and all the usual hand power tools. I also have a table saw but don't use it much so it stays stored.

No trips, ever.

You're giving me hope, however, Im just concerned with breaker spaces. I already have one 100A subpanel running the basement, and the 200A panel is full as well. I think the issue is the number of rooms in the house...

If I were to be able to find a couple of free spaces on the main panel, would you suggest running an additional 100A (or 60A) subpanel to my garage? Could that box be located in the garage on the other side of the house?

 

[pattenp]

You're giving me hope, however, Im just concerned with breaker spaces. I already have one 100A subpanel running the basement, and the 200A panel is full as well. I think the issue is the number of rooms in the house...

If I were to be able to find a couple of fee spaces on the main panel, would you suggest running an additional 100A (or 60A) subpanel to my garage? Could that box be located in the garage on the other side of the house?

Yes the sub-panel can be located in the garage. I think 60A is enough.

 

[twiggles]

Based on this schematic of my home, would you recommend running the 60A panel wiring around the outside of my home? (provided I could find space on my main panel.

The home is a 2 story, with panel in the basement. This prohibits me from running in the attic (I believe). I think I need to go around. While around the front would be shorter, I would not want to disturb my concrete driveway.

 

[pattenp]

With not being there to see what exactly you are dealing with it's hard to say. It would be great if you could stay inside and go up and over to the garage. The outside route is okay but it means you'll need to run conduit.

I assume the outside route is under ground.

 

[twiggles]

With not being there to see what exactly you are dealing with it's hard to say. It would be great if you could stay inside and go up and over to the garage. The outside route is okay but it means you'll need to run conduit.

I assume the outside route is under ground.

Aerial view of home...up and over seems like a challenge. Around the outside would definitely be underground.

Any idea what I should expect to pay to run underground outside in conduit ~150ft of wire?

 

[pattenp]

Are you going to have it all done by an electrical contractor? Or are you going to take on this challenge all by yourself? Digging that trench will be a *****.

 

[twiggles]

I think I would dig the trench myself and leave connections to the electrician. And yes, its going to ****!

I imagine I will be able to save quite a bit by doing the back breaking work myself...?

 

[pattenp]

The parts and pieces if you do it all yourself should be somewhere in the $500 park for the feeder and sub-panel. That would be with using aluminum wire for the feeder. If you use wire that's called Mobile Home Feeder you can run it from panel to panel and it will need to be in conduit inside but can be direct buried outside. But I do recommend it to be in conduit the whole run. You didn't say what state/area/country you are located in so the MHF cable may not be available.

 

[twiggles]

Im in Ohio. I will adjust my profile...I thought it was there. Thanks a lot for your help pattenp. I really appreciate it!

 

[theoldwizard1]

What is brand and model of the main panel ?

Likely you can use tandems on some of your existing breakers to free up 2 slots.

Underground does not require conduit, just underground cable. At that length your going to need some big wire. Would 60A work for you in the garage ? You will save a lot on the wire.

Before going the long way consider going under the driveway, even if you have to cut it. Sprinkler companies would have the equipment to bore under the driveway.

 

[twiggles]

Hey Guys, Here are pics of the panel set up.

 

[ishiboo]

That panel would have only been rated for 42 circuits/42 spaces, because until the 2008 NEC that was the maximum limit for a single board.

I would replace the existing "basement" panel with a new 24- or 32-space load center, while moving some circuits from the 42-space over to that as well. That will give you room in the 42-space for feeding your new garage sub-panel directly from it.

I know you thought 200A was not enough and we think it is (barring electric heat) for most purposes, another option would be to install a new 200A panel next to the existing one, and for now do the same and run it as a sub-panel from the first 200. In the future, if you truly need more capacity, you can then upgrade to "400 amp" service and feed both panels from the meter. I would feed the new garage sub from the new 200A panel if this is the case, and then feed that from a 70-100A breaker from your existing 200A until a time when you figure you need to upgrade your service

 

[ishiboo]

Never seen a home sub "woffer" on its own circuit btw

Keep the breakers from that small panel and put them in your new panel. You cannot reuse that sub in the garage because you will want more circuits and the cheapest/easiest way will be a new main breaker load center, but the breakers should certainly be reused.

 

[twiggles]

Never seen a home sub "woffer" on its own circuit btw

LOL, yeah spelling must not have been that tech's strength. While I was looking at the pictures before uploading, I added a project to my Christmas vacation list...I will be bringing home the label maker from my office to neaten up the panels (and also label my new parts bin in the garage ). I'm ****.

 

[theoldwizard1]

I would replace the existing "basement" panel with a new 24- or 32-space load center, while moving some circuits from the 42-space over to that as well. That will give you room in the 42-space for feeding your new garage sub-panel directly from it.

Excellent Suggestion !

With a 100A breaker feeding that new load center all you have to do is replace the the 5' or so of wire form the the main panel and the breaker for that sub.

BTW, it had been a looong time since I have seen a sub without a main breaker. I guess it is not required because it is located so close to the main load center ?

... another option would be to install a new 200A panel next to the existing one, and for now do the same and run it as a sub-panel from the first 200. In the future, if you truly need more capacity, you can then upgrade to "400 amp" service and feed both panels from the meter.

Overkill, IMHO, but it is not my nickle !

 

[wyliesdiesels]

I wonder if some of those circuits are under utilized and maybe u could combine a few low load circuits together onto one breaker?

 

[theoldwizard1]

I wonder if some of those circuits are under utilized and maybe u could combine a few low load circuits together onto one breaker?

Highly likely, but not worth the hassle.

 

[wyliesdiesels]

Except that it would be more work to put in another panel! Moving breakers and circuits around is easier IMHO!

 

[pattenp]

Excellent Suggestion !

With a 100A breaker feeding that new load center all you have to do is replace the the 5' or so of wire form the the main panel and the breaker for that sub.

BTW, it had been a looong time since I have seen a sub without a main breaker. I guess it is not required because it is located so close to the main load center ?


Overkill, IMHO, but it is not my nickle !

The sub-panel doesn't need a main breaker if it's in the same structure as the main panel. I'm not aware of any distance restriction. But the main disconnect would be a nice thing to have if the sub-panel was on the opposite end of the house from the main panel.