Can I add a 60 amp breaker/line to this panel?

[Disco Biscuit]

I have a 1947 house w/ a main electrical panel (see pic below; in order from top to bottom the breakers are: 125 amp; 20 amp; 100 amp service disconnect; 30 amp (garage); 20 amp). There's the main service disconnect, then 4 circuit breakers---these lead to 3 places: An electrical panel on the main floor, and electrical panel in the basement, and an electrical panel in the detached garage. I believe the house only has 100 amps running to it in total, seeing as the service disconnect is rated at 125 amps and the house is so old.

Right now the garage has a 30 amp capacity (30 amp breaker w/ a 12 gauge wire). I'm wiring up a small workshop that's in the garage and would like to increase this to 60 amps if possible. However, I'm having a hard time determining if I can safely just swap out the breaker on the main box and run a higher capacity line. I do realize that if I were using close to 60 amps in the garage I'd be using over half the total capacity of the house and could risk setting off breakers if enough power was being used in the house, but my real issue here is whether or not the panel itself would be able to manage a 60 amp breaker along w/ everything else in the first place.

Anyone here know how to look at this correctly?

[postvmvs]

I am not an electrician, but from both the top diagram and the helpful blue 'SERVICE DISCONNECT' sticker, I would wager that the 100A breaker in the middle is the service disconnect, i.e. the thing that would disconnect the whole thing from the incoming power from the meter. What the 125A breaker is doing at top has got me -- a branch circuit rated more than the main disconnect???

FWIW I would not take the advice of a random person on the internet for this.

[Disco Biscuit]

Ha...I actually knew that and mistyped it. Glad the picture fixed my mistake.

Don't worry, I'm not going just off of a forum online, but I think it's an easy way to get a first impression from someone who might have an idea.

[Quidnon?]

The double breaker in the middle is the main service disconnect.  The oversized, 125 amp breaker on top serves no purpose, the main would trip first.  As for upgrading the garage service from 30 to 60 amps, yes you can do it, but I wouldn't recommend it.  That type of breaker panel is no longer code valid, replace it outright with a 150 to 200 amp rated panel if you can.  If you do it anyway, be aware that you have to upgrade the copper wiring from the panel to the garage as well.  But the garage having over half of the main panel's power capacity is irrelevent, there is an expectation of non-coincidence of demand.  Said another way, if you are in your garage using high power for short periods of time, and the main house is mostly using light loads such as lighting, you can make it work.

[Quidnon?]

Actually, looking at it again, that's type can have it's main breaker on any set of slots; so the top could still be the main disconnect, but then the sticker should have been moved.  Again, this type isn't code for a main panel anymore.  You really should consider calling an electrician to replace it.

[BudgetSlasher]

I have a 1947 house w/ a main electrical panel (see pic below; in order from top to bottom the breakers are: 125 amp; 20 amp; 100 amp service disconnect; 30 amp (garage); 20 amp). There's the main service disconnect, then 4 circuit breakers---these lead to 3 places: An electrical panel on the main floor, and electrical panel in the basement, and an electrical panel in the detached garage. I believe the house only has 100 amps running to it in total, seeing as the service disconnect is rated at 125 amps and the house is so old.

Right now the garage has a 30 amp capacity (30 amp breaker w/ a 12 gauge wire). I'm wiring up a small workshop that's in the garage and would like to increase this to 60 amps if possible. However, I'm having a hard time determining if I can safely just swap out the breaker on the main box and run a higher capacity line. I do realize that if I were using close to 60 amps in the garage I'd be using over half the total capacity of the house and could risk setting off breakers if enough power was being used in the house, but my real issue here is whether or not the panel itself would be able to manage a 60 amp breaker along w/ everything else in the first place.

Anyone here know how to look at this correctly?

1) I believe that 10 gauge wire is the correct wire for a 30 amp circuit, so it seems your breaker is already to big today for your existing wire.

2) A panel rated for 125 amps, which has a 100 amp breaker should have no problems as result of a 60 amp breaker being install (you could only trip the 60-amp breaker if you overloaded the garage or the 100 amp main breaker if all of your circuits together overloaded it). The main breaker will protect long before the panel itself was in danger from too many amps flowing through it. 

3) Make sure that your garage sub-panel can handle 60 amps and if it has a main breaker remember to adjust that one as well. 

4) Despite my comments and questions below regarding code . . . I googled Challenger electrical panel (for only a few moments) and it was enough that if one was in my house I would be concerned. It seems they can have some serious risks (see: http://inspectapedia.com/electric/Challenger_Electrical_Panels.php) From one discussion it seems that this may have been due to faulty breakers (https://www.nachi.org/forum/f73/challenger-panel-rejected-tower-hill-86547/) and there are approved breakers for the panel (file:///Users/WaggleDance/Downloads/UL%20listed%20C-H%20breaker%20used%20with%20westinghousebryant%20challenger%20panel%20load%20center.pdf)

If I were in your position, I would assess the condition of the panel before going any further with your current project, depending on you skill and comfort level that may mean calling in a professional electrician.

The double breaker in the middle is the main service disconnect.  The oversized, 125 amp breaker on top serves no purpose, the main would trip first.  As for upgrading the garage service from 30 to 60 amps, yes you can do it, but I wouldn't recommend it.  That type of breaker panel is no longer code valid, replace it outright with a 150 to 200 amp rated panel if you can.  If you do it anyway, be aware that you have to upgrade the copper wiring from the panel to the garage as well.  But the garage having over half of the main panel's power capacity is irrelevent, there is an expectation of non-coincidence of demand.  Said another way, if you are in your garage using high power for short periods of time, and the main house is mostly using light loads such as lighting, you can make it work.

I am not sure how it is with panels, but with many other aspects of a home a change in the code (i.e. no longer meets code) are grandfathered and do not have to be replaced; not meeting current code does not mean that it is inherently unsafe. Like I mention above, this panel could have safety issues, which is entirely different than not meeting modern code.

Actually, looking at it again, that's type can have it's main breaker on any set of slots; so the top could still be the main disconnect, but then the sticker should have been moved.  Again, this type isn't code for a main panel anymore.  You really should consider calling an electrician to replace it.

For my own knowledge, how did you determine that the main breaker can be anywhere? From looking at the diagram in the first picture it indicates the main is located between 8 and 9 in the middle of the panel where the sticker is placed.

[Quidnon?]

I am not sure how it is with panels, but with many other aspects of a home a change in the code (i.e. no longer meets code) are grandfathered and do not have to be replaced; not meeting current code does not mean that it is inherently unsafe.

It's still legal, until work has to be performed upon it, then it's not.  It's only grandfathered in so long as it remains in it's current state.  I'm not sure that just changing breakers rises to that level, but I know that at some point, simply working on the panel will require that it be upgraded to meet current code.  I think that it depends upon whether or not a permit is needed for the work in your area.

Actually, looking at it again, that's type can have it's main breaker on any set of slots; so the top could still be the main disconnect, but then the sticker should have been moved.  Again, this type isn't code for a main panel anymore.  You really should consider calling an electrician to replace it.

For my own knowledge, how did you determine that the main breaker can be anywhere? From looking at the diagram in the first picture it indicates the main is located between 8 and 9 in the middle of the panel where the sticker is placed.

By the diagram itself.  The main uses the same type of breakers as the rest of the panel, and there is nothing that stands out about the diagram that would indicate a physical difference between the center slot pair and any other slots.  It's still a common type of sub-panel, just no longer code for the main panel.  The main disconnect is supposed to be well marked, lockable & physically distinct from the branch circut breakers.  If you go to Home Depot and look at what they have available, the main is usually a physically different breaker type, so that it's almost impossible to mistake it, sticker or no sticker.

[postvmvs]

BudgetSlasher is correct that 10AWG is what is used for a for a 30A circuit, which for Romex is an orange cable (white = 14AWG/15A and yellow = 12AWG/20A). Having 12AWG with a 30A breaker, and the 125A breaker that is protecting nothing, stand out as red flags that someone that didn't know what they are doing was involved, and I would check the wiring for the whole house.

If it were my house, I would put a nice Square D panel in there but keep the 100A service, unless the house is overloaded. Replacing the panel is relatively easy, but a service upgrade is not.

My interpretation of the diagram on the panel follows BudgetSlasher's, but the easy way to check is to pop the cover off and see where the wires from the meter connect.

[Spork]

I am not sure how it is with panels, but with many other aspects of a home a change in the code (i.e. no longer meets code) are grandfathered and do not have to be replaced; not meeting current code does not mean that it is inherently unsafe. Like I mention above, this panel could have safety issues, which is entirely different than not meeting modern code.

I always say: I AM NOT AN ELECTRICIAN!   But if I am not mistaken, the act of changing something will remove the grandfathering.  I.e., that panel may be "legal" because it's been there since it was legal.  As soon as you change it, I think you may need to (and probably WANT TO) meet code.   I don't necessarily believe in meddling bureaucracies enforcing code for the sake of a buck.... but I do believe most code is a summation of good common sense and should be followed regardless.

[BudgetSlasher]

I am not sure how it is with panels, but with many other aspects of a home a change in the code (i.e. no longer meets code) are grandfathered and do not have to be replaced; not meeting current code does not mean that it is inherently unsafe. Like I mention above, this panel could have safety issues, which is entirely different than not meeting modern code.

I always say: I AM NOT AN ELECTRICIAN!   But if I am not mistaken, the act of changing something will remove the grandfathering.  I.e., that panel may be "legal" because it's been there since it was legal.  As soon as you change it, I think you may need to (and probably WANT TO) meet code.   I don't necessarily believe in meddling bureaucracies enforcing code for the sake of a buck.... but I do believe most code is a summation of good common sense and should be followed regardless.

I agree with the idea that when something is changed/replaced, it must/should be brought up to code (and also that I am not an electrician).

That being said, I am not clear in this circumstance what the something/it is and what constitutes a change.

Does adding or swapping a breaker to the main panel "change" the panel or only that circuit? If it changes the panel and the panel is replaced does that change also change the sub-panels on the other end of the circuits? Do either of those changes trigger the newer requirements for ground fault and arc fault protection or an ever growing list of circuits? Since the house in question was built in 1947 does that trigger a need for three prong outlets (an addressing/labeling the fact that there may be no mechanical ground)

I agree that code is generally a good summation of common sense (there are something that get a little paranoid at times), but if I went to change a circuit in a otherwise functional panel and code suddenly required me to replace the panel, possibly the sub-panels, install GFICs throughout the wet areas, and replace the existing breakers with arc fault for pretty much everywhere that is no GFIC (and some that are), replace most or all of the outlets in the house, but if I did nothing it would be perfectly fine to keep on going. . . . . well I will let people draw their own conclusions.

[Spork]

I am not sure how it is with panels, but with many other aspects of a home a change in the code (i.e. no longer meets code) are grandfathered and do not have to be replaced; not meeting current code does not mean that it is inherently unsafe. Like I mention above, this panel could have safety issues, which is entirely different than not meeting modern code.

I always say: I AM NOT AN ELECTRICIAN!   But if I am not mistaken, the act of changing something will remove the grandfathering.  I.e., that panel may be "legal" because it's been there since it was legal.  As soon as you change it, I think you may need to (and probably WANT TO) meet code.   I don't necessarily believe in meddling bureaucracies enforcing code for the sake of a buck.... but I do believe most code is a summation of good common sense and should be followed regardless.

I agree with the idea that when something is changed/replaced, it must/should be brought up to code (and also that I am not an electrician).

That being said, I am not clear in this circumstance what the something/it is and what constitutes a change.

Does adding or swapping a breaker to the main panel "change" the panel or only that circuit? If it changes the panel and the panel is replaced does that change also change the sub-panels on the other end of the circuits? Do either of those changes trigger the newer requirements for ground fault and arc fault protection or an ever growing list of circuits? Since the house in question was built in 1947 does that trigger a need for three prong outlets (an addressing/labeling the fact that there may be no mechanical ground)

I agree that code is generally a good summation of common sense (there are something that get a little paranoid at times), but if I went to change a circuit in a otherwise functional panel and code suddenly required me to replace the panel, possibly the sub-panels, install GFICs throughout the wet areas, and replace the existing breakers with arc fault for pretty much everywhere that is no GFIC (and some that are), replace most or all of the outlets in the house, but if I did nothing it would be perfectly fine to keep on going. . . . . well I will let people draw their own conclusions.

My short answer to this is: I don't know.  (I suspect Paddedhat will show up and let us know.)

You're obviously correct that it can't cascade down to receptacles and such.

[BudgetSlasher]

I am not sure how it is with panels, but with many other aspects of a home a change in the code (i.e. no longer meets code) are grandfathered and do not have to be replaced; not meeting current code does not mean that it is inherently unsafe. Like I mention above, this panel could have safety issues, which is entirely different than not meeting modern code.

I always say: I AM NOT AN ELECTRICIAN!   But if I am not mistaken, the act of changing something will remove the grandfathering.  I.e., that panel may be "legal" because it's been there since it was legal.  As soon as you change it, I think you may need to (and probably WANT TO) meet code.   I don't necessarily believe in meddling bureaucracies enforcing code for the sake of a buck.... but I do believe most code is a summation of good common sense and should be followed regardless.

I agree with the idea that when something is changed/replaced, it must/should be brought up to code (and also that I am not an electrician).

That being said, I am not clear in this circumstance what the something/it is and what constitutes a change.

Does adding or swapping a breaker to the main panel "change" the panel or only that circuit? If it changes the panel and the panel is replaced does that change also change the sub-panels on the other end of the circuits? Do either of those changes trigger the newer requirements for ground fault and arc fault protection or an ever growing list of circuits? Since the house in question was built in 1947 does that trigger a need for three prong outlets (an addressing/labeling the fact that there may be no mechanical ground)

I agree that code is generally a good summation of common sense (there are something that get a little paranoid at times), but if I went to change a circuit in a otherwise functional panel and code suddenly required me to replace the panel, possibly the sub-panels, install GFICs throughout the wet areas, and replace the existing breakers with arc fault for pretty much everywhere that is no GFIC (and some that are), replace most or all of the outlets in the house, but if I did nothing it would be perfectly fine to keep on going. . . . . well I will let people draw their own conclusions.

My short answer to this is: I don't know.  (I suspect Paddedhat will show up and let us know.)

You're obviously correct that it can't cascade down to receptacles and such.

I hope so, I've got some basic electrical work coming up and it would be nice to know what I need to be aware of upgrading as I add/change a few circuits.

[paddedhat]

Grandfathering mechanical systems is the only way we can really afford to rationally operate any mechanical systems, be they residential, or larger. There is nothing that says that changing a breaker triggers a need to replace the panel. Which send the whole job down the rabbit hole, BTW, since it would basically require a total service upgrade. The panel's main breaker is whatever 2 pole breaker is fed from the load side of the electric meter, in this case. Ideal? No. Acceptable by 2016 NEC standards? no.  Safe? it sure is.  The OP needs to swap the 30A 2Pole for a 60, and install the proper gauge wire to a properly sized sub-panel.  Keep in mind that sub-panels are four wire feed, with two hots, a white insulated neutral and a green or bare ground wire. There needs to be a separate ground and neutral bar in the panel, and they are not bonded together.

[Spork]

Keep in mind that sub-panels are four wire feed, with two hots, a white insulated neutral and a green or bare ground wire. There needs to be a separate ground and neutral bar in the panel, and they are not bonded together.

I never thought about this, but it makes absolute sense. 

Is there any leeway based on distance between the two panels?  In other words, I'm thinking about my own panel, which has a sub-panel butted up right against it.  I don't recall without peeking inside, but I vaguely think the sub panel has a single neutral/ground bar. 

[BudgetSlasher]

Keep in mind that sub-panels are four wire feed, with two hots, a white insulated neutral and a green or bare ground wire. There needs to be a separate ground and neutral bar in the panel, and they are not bonded together.

I never thought about this, but it makes absolute sense. 

Is there any leeway based on distance between the two panels?  In other words, I'm thinking about my own panel, which has a sub-panel butted up right against it.  I don't recall without peeking inside, but I vaguely think the sub panel has a single neutral/ground bar.

When my sub-panels were installed they came with the ground and the neutral bar tied together. That tie was removed and 4 wires run to connect the two. And distance did not play a role (one sub panel is within arm's reach of the main panel).

Also, I believe that a separate grounding rod is required for panel in detached structures (in addition to the run back to the main panel). But, I might be mis-remembering.

 

[Disco Biscuit]

Thanks for all the replies; the discussion above has been interesting.

A couple of notes:
1) I think I was wrong when I said 12 gauge wire is installed currently on the 30 amp pole to the garage---the coloring of the insulation threw me, but it does look like it's 10 gauge.
2) The garage subpanel does have a neutral/ground bar. I believe it goes to ground, but I guess I haven't actually checked under the drywall to ensure it goes all the way down. The garage was built in '85 (a detail I forgot to mention in the OP), so while still old, not nearly as much as the house
3) Budgetslasher's note about Challenger panels does give me pause and make me want to have an electrician at least look it over for signs of problems. So...I guess while I do that I can casually mention that I want to add a 60 amp breaker and see what they say.
4) The 100 amp service to the house SHOULD be enough. My house doesn't use a ton of energy. Lights (mix of LED/CFL) and computers mostly, along w/ common appliances. The only thing that makes me hesitate is the A/C unit, furnace, and 2 dryers (basement apartment where my brother is). If I were to run a table saw, small A/C or heater, dust collection and lights in the shop, that could be up to 1/2 the amp supply to the house. But, as mentioned above, a service upgrade will be a pain and will involve new panel, working w/ the city to schedule a power shut off, and honestly, it'll be costly because I don't trust my very basic knowledge of electrical to do the work myself.

[BudgetSlasher]

Thanks for all the replies; the discussion above has been interesting.

A couple of notes:
1) I think I was wrong when I said 12 gauge wire is installed currently on the 30 amp pole to the garage---the coloring of the insulation threw me, but it does look like it's 10 gauge.

Yeah that happens, my house was built in the 90's and all of the original wiring regardless of gauge is the same color, makes it really easy to tell what has been added (unless it is 14 gauge).

[sokoloff]

2) The garage subpanel does have a neutral/ground bar. I believe it goes to ground, but I guess I haven't actually checked under the drywall to ensure it goes all the way down. The garage was built in '85 (a detail I forgot to mention in the OP), so while still old, not nearly as much as the house

For safety, and to meet modern code, there should be TWO bars, electrically isolated from each other, one of which is neutral and tied to the main panel with one of the current carrying wires, and the other should be ground, tied to the chassis of the subpanel, to the earth conductor to the main panel, and if in a detached building, to an acceptable earth safety ground (a UFER in the slab or two grounding rods driven near the foundation of the detached building)

One neutral/ground bar is only permitted in the first (main) service panel. All subpanels need isolated neutral and ground.