# 60 amp sub panel for a detached garage



## canyonbc (Jan 8, 2010)

Trying to think long term here. 

I am still planning out the 16 x 20 detached garage about 125 feet from the main service panel on the house 

The garage at first will be used as a quilt room. Building it is as a garage to widen its appeal when it comes times to sell the place. 

Along those lines, the building will be built with a few 120 volt outlets, one ceiling fan, and some recessed lights.

I am pretty confident for these basic needs a 60 amp sub panel should be plenty but what I do wonder is can someone ever run 220 to the garage off a 60 amp panel???

Example say i wanted to run Lincoln 175 or 180 Mig welder - a 220 welder. 

Can you do that on a 60 amp sub panel or would this be too much???

Thanks,
Mike


----------



## Scuba_Dave (Jan 16, 2009)

It all depends upon the rating of the welder & required power

A 60a panel will be a 240v panel
Not that many people ever run a 120v panel


----------



## jlhaslip (Dec 31, 2009)

Upgrade to a 100 Amp Panel now if you can. Use a 60 Amp for the Feed Breaker and upgrade it when you need to.
The price difference in the panel won't be much (I don't think).


----------



## vsheetz (Sep 28, 2008)

I had only a couple 120v circuits in my detached 24x30 workshop/garage - and I recently upgraded to a subpanel fed by a 60a breaker in my main panel. I found it to be a good balance of cost and effort while providing ample power for tools, lights, etc. I have large table saw, welder, heater, compressor, chop saw, lights, etc. 

I used a $55 100a GE brand workshop subpanel from Lowes, #6 THWN wire in conduit from the main panel 60a breaker, etc. Then in the shop are three 240v circuits, several 120v circuits for outlets, interior and exterior lights, and a RV recepticle.

Details of how to make it happen are readily available via search as this is a common topic.


----------



## canyonbc (Jan 8, 2010)

vsheetz said:


> I had only a couple 120v circuits in my detached 24x30 workshop/garage - and I recently upgraded to a subpanel fed by a 60a breaker in my main panel. I found it to be a good balance of cost and effort while providing ample power for tools, lights, etc. I have large table saw, welder, heater, compressor, chop saw, lights, etc.
> 
> I used a $55 100a GE brand workshop subpanel from Lowes, #6 THWN wire in conduit from the main panel 60a breaker, etc. Then in the shop are three 240v circuits, several 120v circuits for outlets, interior and exterior lights, and a RV recepticle.
> 
> Details of how to make it happen are readily available via search as this is a common topic.


Thanks for the knowledge

Sounds like there is not much of a cost difference between the 60 and the 100. I will do some more research. 

Only concern, and need to call some companies and get some bids is can my 200 amp (assuming the main board is a 200 amp on the house) handle a 100 amp sub panel. 

Thanks,
Mike


----------



## Scuba_Dave (Jan 16, 2009)

My 200 panel has (2) 100a subs & a 60a sub


----------



## canyonbc (Jan 8, 2010)

Scuba_Dave said:


> My 200 panel has (2) 100a subs & a 60a sub


Wow, thats impressive. 

Good news to know. 

Thank you.


----------



## vsheetz (Sep 28, 2008)

canyonbc said:


> Sounds like there is not much of a cost difference between the 60 and the 100.


The dollar and percentage difference is quite a bit, about double or more for materials when I worked it up - the cost delta is in the larger wire and the 100a breaker for the main panel, not the subpanel. Since I could not see a need for the additional power, I went with 60a.

I have learned the "why nots" really run up the cost of projects, so I really try to eliminate them... :no:


----------



## canyonbc (Jan 8, 2010)

vsheetz said:


> The dollar and percentage difference is quite a bit, about double or more for materials when I worked it up - the cost delta is in the larger wire and the 100a breaker for the main panel, not the subpanel. Since I could not see a need for the additional power, I went with 60a.
> 
> I have learned the "why nots" really run up the cost of projects, so I really try to eliminate them... :no:


Yes, yes they can. 

Trying to keep the cost down but also want to weigh out what is going to be the best long term budget. 

Well have a budget want to stick in, will get the prices for both and make this decision at another time.


----------



## JohnJ0906 (Mar 18, 2007)

At 125 feet, you will have to upsize the wire to compensate for voltage drop. I came up with #4 copper or #3 aluminum, for a 60 amp sub.


----------



## canyonbc (Jan 8, 2010)

JohnJ0906 said:


> At 125 feet, you will have to upsize the wire to compensate for voltage drop. I came up with #4 copper or #3 aluminum, for a 60 amp sub.


John 

Thank you for the advice an information. 

A couple questions if you dont mind?
Would you recommend copper over aluminum for any specfic reason or visa versa? 
If you do not mind sharing how did you equate a #4 copper for the 125 feet with a 60 amp sub panel? Am i safe to assume there is no website to equate (something like they have for equating cubic volume of concrete) or a calculator ( like they have for figuring how many studs in while)? 

Thanks again 
mike


----------



## Scuba_Dave (Jan 16, 2009)

Voltage drop is calculated by the distance & the load
So for a 60a panel the Max drop is around 7v
Upgrading to #4 wire makes it only 4.5v drop =3.8%
Usually try to keep it under 5% is my understanding

If your load is going to be 40a or less on the 60a panel then you are OK with #6


http://www.csgnetwork.com/voltagedropcalc.html


----------



## canyonbc (Jan 8, 2010)

Scuba_Dave said:


> Voltage drop is calculated by the distance & the load
> So for a 60a panel the Max drop is around 7v
> Upgrading to #4 wire makes it only 4.5v drop =3.8%
> Usually try to keep it under 5% is my understanding
> ...


Thank you for the information and website, I am going to learn some more.


----------



## canyonbc (Jan 8, 2010)

Scuba_Dave said:


> Voltage drop is calculated by the distance & the load
> So for a 60a panel the Max drop is around 7v
> Upgrading to #4 wire makes it only 4.5v drop =3.8%
> Usually try to keep it under 5% is my understanding
> ...


This question is for all. 

Ok, I have been playing around with the site you suggested, great calculator thank you. 

To help my self understand 

In the required data entry of the calculator this is a box that states

Select Voltage and Phase - Would this be, what the power of the main panel (so I am pretty sure the main panel is a 200 amp so I would click "240 volts 1 phase" or is this something completely different???

But then it says enter load, (feeling quite dumb at this point) enter load would that be the new sub panel or my starting panel?

Thanks everyone again for all the info. 

I am going to do what I should have done and cruise around reading the suggested sight.


----------



## Scuba_Dave (Jan 16, 2009)

240v 1 phase, 6 AWG is size of wire, 60a is the load - size of the sub-panel 
OR anticipated Load
I always prefer my Load to be LESS then the breaker size & wire can handle
Distance - 1 way


----------



## vsheetz (Sep 28, 2008)

Scuba_Dave said:


> Voltage drop is calculated by the distance & the load
> So for a 60a panel the Max drop is around 7v
> Upgrading to #4 wire makes it only 4.5v drop =3.8%
> Usually try to keep it under 5% is my understanding
> ...


 
Not sure why the calculator says to use 1/2 length of the circuit - when I do I getting differing results... acceptable results for #6 methinks.


----------



## Scuba_Dave (Jan 16, 2009)

Total circuit ONE WAY is 125'

Power must go TO the device & back again
--at least what I was told


----------



## canyonbc (Jan 8, 2010)

Scuba_Dave said:


> Total circuit ONE WAY is 125'
> 
> Power must go TO the device & back again
> --at least what I was told


Yes it is about 125 feet from the main panel box to the sub panel box on the detached garage.


----------



## HouseHelper (Mar 20, 2007)

Half the circuit length in this case is 125ft... total circuit length is 250 ft (out and back).


----------



## canyonbc (Jan 8, 2010)

vsheetz said:


> Not sure why the calculator says to use 1/2 length of the circuit - when I do I getting differing results... acceptable results for #6 methinks.


On the thing here it says "Select Voltage and Phase" - now (accepting that my panel is 200 amps) - is that 240 volts? 

1 phase, 3 phase - What does this mean? 

Thanks again for all the knowledge


----------



## canyonbc (Jan 8, 2010)

HouseHelper said:


> Half the circuit length in this case is 125ft... total circuit length is 250 ft (out and back).


So say I were to use a # 3 awg I would need a min of 300 feet to be on the safe side of cable to run back and forth circuit to circuit correct?

What does awg stand for? 

Does places like Lowes and Home D. carry wire this big for exterior applications? or do you need to go to a electrical specific supply company? 

Even though this would be ran in the gray pvc pipe underground you still need to get exterior grade wire correct? 

Thanks,
Mike


----------



## Scuba_Dave (Jan 16, 2009)

THWN is exterior grade wire - allowed to be in buried circuit - HD & Lowes do carry it
AWG is the wire size - American Wire Gauge

#4 wire drops the voltage drop to 4.5v, 1.9% - well within limits


----------



## canyonbc (Jan 8, 2010)

Scuba_Dave said:


> THWN is exterior grade wire - allowed to be in buried circuit - HD & Lowes do carry it
> AWG is the wire size - American Wire Gauge
> 
> #4 wire drops the voltage drop to 4.5v, 1.9% - well within limits


Thank you for some more knowledge. 

Now maybe you or someone else can confirm with me here and it is something I want to look at price, or at least what is the difference. 

if I were to go to a # 3 wire that would be sufficent for a 100 amp sub panel correct?


----------



## codeone (Dec 31, 2009)

canyonbc said:


> if I were to go to a # 3 wire that would be sufficent for a 100 amp sub panel correct?


#3 UF cable buried is only rated for 85A
#2 UF cable buried is rated 95A However you can fuse at 100A
These are copper conductors.


----------



## Scuba_Dave (Jan 16, 2009)

If running in conduit then #3 THWN is rated at 100a in 75c rating column
UF uses the 60c rating column

Voltage drop would be 5.9v - 2.9% with a 100a load
If your load was MAX say 60a then the voltage drop would be 3.6v = 1.5%


----------



## vsheetz (Sep 28, 2008)

Scuba_Dave said:


> Total circuit ONE WAY is 125'
> 
> Power must go TO the device & back again
> --at least what I was told


I had thought of that - but still seemed strange to ask the question that way...

I don't see it has a big problem to use #6, unless one would be consistantly or often nearing the 60a current draw.


----------



## canyonbc (Jan 8, 2010)

codeone said:


> #3 UF cable buried is only rated for 85A
> #2 UF cable buried is rated 95A However you can fuse at 100A
> These are copper conductors.


Well thank you for the information. 

Are these put out by the manufacture of is that papa NEC Code.?

Just Wondering and Learning


----------



## canyonbc (Jan 8, 2010)

Scuba_Dave said:


> If running in conduit then #3 THWN is rated at 100a in 75c rating column
> UF uses the 60c rating column
> 
> Voltage drop would be 5.9v - 2.9% with a 100a load
> If your load was MAX say 60a then the voltage drop would be 3.6v = 1.5%


Not sure what the 75c stands for 

But by code and good venture a # 3 THWN can handle a 100 amp ???


----------



## Scuba_Dave (Jan 16, 2009)

There are different Temp ratings for wire connections under NEC code
60c (centigrade) column, 75c & 90c

Different type of wire & different types of uses & you look under a different column to see what the wire is rated to carry

I'm not sure who exactly rated the wire (originally) possibly the NEC
But the rated uses are listed in the NEC & controlled by the NEC code
So by the NEC code #3 THWN will handle 100a



vsheetz said:


> I had thought of that - but still seemed strange to ask the question that way...


I thought it weird too...took some getting used to
I have seen some Calc tables where you can choose between total distance & 1/2 distance
It can be confusing, especially if someone does not know the proper value to enter


----------



## canyonbc (Jan 8, 2010)

Scuba_Dave said:


> There are different Temp ratings for wire connections under NEC code
> 60c (centigrade) column, 75c & 90c
> 
> Different type of wire & different types of uses & you look under a different column to see what the wire is rated to carry
> ...


Thank you, 

That should settle it, I know the county the garage will be in goes by the NEC Code so I should be good to go. 

Thanks everyone again.


----------



## codeone (Dec 31, 2009)

canyonbc said:


> Well thank you for the information.
> 
> Are these put out by the manufacture of is that papa NEC Code.?
> 
> Just Wondering and Learning


The NEC! :yes:


----------



## canyonbc (Jan 8, 2010)

Good to know


----------



## canyonbc (Jan 8, 2010)

As I continue to learn and dial in the electrical plan for the garage

I wanted to run some things by everyone and get some opinions. 

I think it is ok to put a link to The Home Depot of the breakers I am talking about, figure it would be easier to show some links so everyone can really see what I am asking about. 

60 amp 2 inch double pole circuit breaker
http://www.homedepot.com/Electrical...splay?langId=-1&storeId=10051&catalogId=10053

100 amp 2 inch double pole circuit breaker 
http://www.homedepot.com/Electrical...splay?langId=-1&storeId=10051&catalogId=10053

- Ok to recap the situaion, have a main panel with 200 amp breaker going approx. 125 feet to a detached garage, have not determined yet if I want to put a 60 or 100 amp sub panel. 

Question: 
At the main panel would I put on of these breakers in and then run # 3 awg thwn to the sub panel?????

Has anyone used these is this the way you would do it, if not what would you do and why?

Thanks,
Mike


----------

