6 throw breaker panel

Hello, I recently purchased a home built in 1980. On the exterior of the home, next to the meter, is a breaker panel with six breakers. I have started having issues with one of the breaker tripping if we run the dryer and anything else that uses a good bit of electricity (full house attic fan, microwave and dishwasher, dishwasher and washing machine...). I have narrowed down what the six breakers supply as nothing is marked.

50A - Stove 40A -Entire house
60A - Downstairs Air handler 40A - Upstairs Heat pump
60A - Upstairs Air handler 40A - Downstairs Heat pump

I am no electrician but it doesnt seem correct to have an entire house (minus the items on the other 5 breakers) running on a 40A breaker. I looked at the wire casing to try and determine the gauge of the wires but I didnt see any markings. They appear to be of the same size as the 50A and 60A breaker wires but I do not want to assume. I am looking for any advice or guidance that anyone can offer. The heat pump breakers seem to be over rated for the wire size but I am also unsure of this one also. I will attach a picture for reference. I also know that the bottom right 40A is double tapped, my pool pump is attached to this breaker. That will be my next task to fix once I figure out the breaker tripping. Any advice on fixing that would be great also. The dryer is on its own breaker inside the house in the sub panel.....



http://i37.photobucket.com/albums/e9...pssjgsdndd.jpg

 

That appears to be your main panel. Can you elaborate. Are you saying each of these breakers supplies two loads directly or are each of these connected to a subpnanel that has breakers for these devices..

 

I hijacked your picture. That is a main disconnect panel. It appears to be a 200A service and you are pushing it to the max.

40A for the house is definitely not enough power. I circled the double connections on a 2P40A breaker in red. Is this the house breaker ? You should not have two circuits connected into one breaker.

In the blue box..... the neutrals/grounds are all stuffed into one lug and there is no anti oxidant on the wires. Actually... I don't see any anti oxidant on any of the aluminum wires.



Not sure how old the house and wiring is but I don't see the correct wiring to the indoor hose panel either. It should be fed with a four wire cable.

The OP has all electric heating. The 2P60's feed the two air handlers with backup electric heat coils.
The 2P40's supply the two outside heat pump condensors.

 

That is my main panel. The double tap breaker is one of the Heat pump breakers with a pool pump attached to it. Not sure why it was wired like that but its on the list of issues. The house was built in 1980, I assume this all the original layout excluding the pool pump. The breaker in the top right corner is the house breaker. None of the other breakers in this panel are attached to the interior sub panel. These are main (and only) breakers for all of those items.

 

Ray2047, I was giving the location of each breaker in the main panel.
On the left from top to bottom is....
50A to Stove
60A to Downstairs Air handler
60A to Upstairs Air handler

On the right from top to bottom is....
40A to sub panel inside house
40A to upstairs Heat pump
40A to downstairs Heat pump

The 5 breakers that are for specific items are the only breakers for those items. Only the 40A in the top right goes to the sub panel.

 

Is this breaker trip problem happening during the heat of the day given the heat waves around the country? Sometimes with outdoor panels direct sunlight can raise the temp up enough to cause nuisance tripping even during moderate load conditions.

 

Ben, That is a good thought... I can make the breaker trip by turning on several things at one time at anytime of the day. I wish I could contact the seller and see if the breaker was replaced and why a 40A was used. Just doesnt seem right to me. I was hoping someone more familiar with wires would be able to tell me if any of them are over or under rated for the breakers.

 

I don't think it's a wire size problem. The 40A breaker feeding the house is probably #6 aluminum wire, which is correctly sized (although inadequate for modern living it seems). I think you're just using more than 40A in the house. The electric dryer alone uses up to 30A. Add a bit more to that (such as the microwave) and you're over the limit.

Long term what I would do in this case is to replace this panel with a ~20 space 200A main breaker panel. This would give you the flexibility to power the existing loads from this panel, and add a proper breaker for the pool, and run a new 100A subpanel feeder into the house. Heck you could even get a panel with feed-through lugs and run a 200A feeder into the house. This depends on what size the inside panel is and if you want to replace it.

BTW, the smaller-than-you-might-expect heat pump wires are OK due to dedicated motor sizing rules which are different than general-purpose circuits.

 

So if its #6 aluminum I can only go with 40A, if its #6 copper can I go with 60A? Just trying to learn as much as I can....

If I replace the panel with a 200A main breaker panel, I would probably have an electrician do that part as I am not comfortable dealing with power on that level. I assume this panel would have one main shutoff for the entire house (200A main breaker)? Thats how I could keep the existing breakers on the outside of the house and they not be main breakers? If I wanted to move breakers from inside the house to the exterior panel, once replaced, would I need to run all new wiring or can the wires be spliced at the interior panel? I am pretty sure the answer is no splice but I wanted to ask to be sure. If I run 100A to the subpanel I assume I would need to run all new wiring?

 

The wires could be spliced inside and extended to the outside. An easier solution would be to install a larger feeder to the panel inside and leave the inside circuits alone.

 

If I installed a larger feed to the subpanel would I be pushing the limits of the existing main panel? or are you saying to replace the existing main panel and keep everything else inside like it is? The inside subpanel is maxed out with breakers. I noticed that last night. I assume thats why someone double tapped one of the exterior breakers for the pool pump.

 

If the inside panel is only rated at 60 amperes then you should consider upgrading it. If it is rated at 100 amperes or more then just changing the feeder conductors to #4 or possibly #2 will give you more power. It may make sense to increase the feeder AND add a sub-panel adjacent to the existing inside panel.

Definitely replace the outside panel with a higher amperage model with a main circuit breaker. 200 amperes is common so often lower in price than either a 125 or 150 ampere panel. If you don't add the second sub-panel inside then you can run new circuits to the new outside panel.

Please post a picture of the inside panel as well as the manufacturer and model number. You may be able to add tandem circuit breakers which would give you more circuits after upgrading the feeder.

 

Thanks Furd. I will get a picture of the inside of the sub panel tonight. I have a picture of the exterior but all it shows is its a GE. Is it typical to have a main panel on the exterior with standard breakers and then a sub panel inside? This is all new to me as my previous home only had one panel in the garage with the main shut off.

Here are all the pics I currently have.. Will get the other posted this evening.

 

"Is it typical to have ..."

Yes it is common although sometimes there is no breaker panel outside and the main panel is inside.

The "main" panel onthe outside of the house could take a variety of forms:

1. As it is now, with 6 breaker sets,

2. With one main breaker set up top plus many individual branch circuits below it in two columns similar to your subpanel,

3. With six breakers up top similar to what you have now and several other breakers in a separate two column group below where one of the six up top controls the entire separate group below.

4. With fewer breaker sets, possibly just one.

With any of these forms of panels, a fat feeder cable can run from one breaker (more commonly from a double breaker set) over to a subpanel elsewhere in the house. You have one such feeder cable as things stand today.

The significance of the number 6 is that it must be possible to turn off all the power to the house by flipping no more than six breaker handles all within reach while you are standing in one place.

Your inside panel is rated for so many amps, let's call it X amps. This means that the feeding panel (the one outside) must have a breaker no greater than X amps (currently 40 amps) supplying an appropriately sized feeder cable to that inside panel.

Your outside panel is also rated for so many amps, let's call it Y amps. There is some formula used to relate the sum of the amperes ratings for the six breakers to Y amps; I don't know what that formula is.

It is not practical for the house to have just the 6 breaker sets in the outside panel and no inside panel. Individual branch circuits for lights and receptacles must have breaker protection no greater than 20 amps and six breaker positions is not enough to supply enough general purpose branch circuits and also the heating and air conditioning you currently have.

 

Thanks for all the info. I guess my next task is to determine what amps the sub panel can handle and what gauge my wire from the main panel to the sub panel is. That will help determine if I need to replace the sub panel and wiring.

If the sub panel can handle 60A, the cable is 6 gauge copper, then it sounds like my temporary fix would be to swap out the 40A breaker for a 60A... Is that correct? I know I need additional breakers so I will plan to replace the main panel with a single throw main breaker and additional branch circuits. If this is all correct I will be able to move my well pump and hot water heater to the new outside panel. These two items would be easy to rewire as they are both under the house. I think that would help with my issue also... Thoughts?

 

There should be a label on the inside of the door on your sub-panel that states the ampere rating of the panel. There should also be a model number that may have something like 20-40 in the number, or maybe 2-30 or maybe just 20. There will also be a diagram showing various arrangements of circuit breakers.

I notice that there are 20 spaces for full-size circuit breakers. Often, but not always, such a panel will also allow for "tandem" circuit breakers in some positions. The model number and the diagram will confirm whether or not your panel will accept tandems.

 

Here is the inside of the subpanel and the diagram. Its kind of hard to read, I can try to get better pictures if you need but the writing isnt much better in person... I cannot find any markings on the wires for what size they are but they are aluminum coming in to the sub panel.

 

That is a 20 space, 24 circuit panel. The bottom two spaces on each side may use tandem circuit breakers. In other words, you have a maximum of four more single pole (120 volt) circuits that can be added to that panel.

It is also rated at 125 amperes maximum so IF you can replace the existing feeder conductors with larger ones (dependent upon the temperature rating of the main lugs, which I cannot find) you can increase the load on that panel significantly.

 

The model is GE TLM-2012S mod. 1

 

Thanks! How would I go about finding the temp rating of the main lugs? What size would you increase the feeder conductors with? Can the current outside panel handle the larger load? I know I want to replace the outside panel at this point but would like to be able to save a little and keep the inside panel if possible. I will have to research about the tandem circuits as I have never heard of that. Thanks again for all your help!

Also, what would you recommend for a replacement panel, both interior and exterior?

 

You can keep the inside panel as long as you want to.

You will probably want an outside panel with a top breaker plus some quantity of branch circuit breakers in two columns below. The amperes rating for the new breaker set in the new outside panel serving the existing inside panel will probably be limited by the existing cable.

You can run a new fat cable (3 conductors plus ground) out of the new outside panel to another inside subpanel.

If you do not upgrade the cable to the existing inside subpanel you might as well not investigate tandem (single wide double handle) breakers. With just 40 amps coming into the existing inside panel you don't want to add more branch circuits there but may end up moving some of those circuits to the new second inside panel or spliced up to a new outside panel with many more breaker slots.

Actually, if the existing inside panel does not have a 3 conductor plus ground cable feeding it, you should not add any more circuits to it. (If the feed cable or separate wires are in a metal conduit up to the main panel with all metal fittings and clamps then a ground wire is not needed.)

 

I will be limited by the existing cable from the main to the sub? If so, what size cable should I go to? I guess that would be determined by the temp rating on the main lugs in the sub panel?

Do I need a fat cable if I only upgrade the wiring and not the inside panel?


I think what I am leaning toward is this...
1st - upgrade 40A breaker in the main panel to the sub panel (if I can with the current wiring)
2nd - upgrade the wiring from the existing main to the sub panel
3rd - upgrade the main panel with a single main with additional breaker slots
4th - move some of the existing breakers in the sub panel to the new main panel

Does this sound like a good plan? I want to safely get the current 40A breaker to stop tripping. What is the largest breaker I can install with 6 gauge aluminum wiring, 40A?

 

With #6 aluminum the largest breaker you can use is 40A under the newer conservative 60C sizing rules. In the recent past 50A would have been acceptable.

However, just upping that breaker is not a great solution as it effectively increases your total service size due to having 6 main disconnect breakers in your first panel. Your service size is the sum total of those breakers, (290A) in what appears to be a panel and conductors sized for only 200A. If you actually do the math on the heat pumps and the other loads to back out the margins for oversized breakers, you're probably right at or just over 200A. This means your current panel as it is configured is already at or above the safe maximum your service entrance can handle. This makes sense as to why they only ran 40A into the house -- the rest of the capacity is already spoken for by the electric heat equipment.

The options at this point are to either do a full demand load calculation to determine what the actual service size should be; and if it's 200A or less, replace the outdoor panel with one that has a single 200A main breaker to limit aggregate current. Then you could upgrade the feeder into the house to any size you like as the main breaker will ensure total current is less than 200A. If the demand calculation yields greater than 200A, the next step would be to have your service upgraded to 320A (likely split to 2 200A panels).

To answer your question several posts above: aluminum is less conductive than copper so it carries fewer amps for wires of the same gauge.

 

Thanks for all the info.. Its greatly appreciated. I think what will be the best route for me at this point would be to have a new main panel installed (I will need to research how to figure demand load calc). Once the new main is installed I can move the water heater, well pump and dryer to the new main panel. This will greatly reduce the load on the sub panel until I am able to up the feed wires to the sub panel. This will allow me to separate the pool pump to its own breaker in the main panel and have some left over in the sub panel if I need to ever add more breakers. Does this sound like a good plan?

I have also been reading about main panels and panels with pass thru for sub panel. What is the better option? Keep the sub panel on a breaker from the main panel or have a pass thru, I assume this means you skip the breaker in the main panel instead of having a dedicated breaker just to feed the sub? If all this is true, can I start off installing the 40A breaker to the sub panel and then later install from the pass thru when I upgrade the wires? Just trying to see all my options before I make a decision.

 

Sounds like a decent plan. Any of the methods you propose for feeding the subpanel would be OK. If you use feed-through lugs the subpanel and subpanel feeder need to have the amp rating as the main panel. If you use a breaker to feed the sub, you can go with fewer amps. You may or may not want to run the full 200A into the house -- 60A or 100A will be more than adequate once you move the loads you mentioned from the inside panel to the outside, but there's no problem going with 200A just with some added material cost and cable thickness.

 

Is this a decent main panel? If not, what should I be looking for?

GE 200 Amp 32 Space 40 Circuit Outdoor Main Breaker Load Center Value Kit-TM3220RCUB2K - The Home Depot

 

That would be a good choice. Some of the pros here aren't as enthusiastic as I am about GE but I like them because the breakers are cheap and sold almost everywhere. Size wise it is a very good choice.

There is a likelihood you may need to change your entire service including the meter socket. The pros can address that.

 

I have another question after thinking about this over the weekend. If I replace my main panel with a new 200A main, will I still have some of the same issues I have currently? I have been told that I am maxing out my current main panel with the breakers that are currently installed. If I go with a new 200A main, install a 60A or 100A to the sub panel, move the dryer, water heater and well pump to the new 200A main. How will this not be maxing out the new main? I may be missing something at this point but I cant figure out how that would work… Is 200A typical for a main panel feed? I looked at my meter and seen that its rated at 240A.

 

It is actual load not the total of the breaker amps that determine if a panel is overloaded. Some of the breakers at times have no load or are have only small loads on them so you usually don't even approach the total of the breakers.

 

So is a 200A main panel typical for a single residential application? I still need to do the load demand test.

 

Between my Service (main) panel (200 ampere rating) and two sub-panels I have over 900 amperes worth of circuit breakers installed. In the 16-1/2 years I have lived in this house I seriously doubt I have ever exceeded a total of 100 amperes of load.

 

The demand load calculation will be the decider on the service size. That tells you what the expected load will be in your house given typical usage patterns. It does not simple sum up loads, it takes in to account that not everything will run at once; and reasonable assumptions like the heat and air cond should not run at the same time.

However, you still need a means to enforce the maximum amps just in case everything is running at the same time.

My guess is that your demand load is going to come out somewhere around 150A - 175A, meaning a 200A service will be acceptable, but you still need an overall main breaker to enforce that limit should you get close to it. With the 6 main breakers, any one of them cannot enforce the limit so you have to consider only the total as it is configured today.

 

That makes a lot of sense. I really appreciate every ones help and guidance. I know my own limits on what I will and will not work on but also like to know a little more than the typical home owner when talking to the "professionals".

 

I know its been awhile but I finally found some markings on the wire casing. For some reason I was thinking the markings would be on the black or read wire.... This is what I found / 2-4 al 1-4 al type SE cable style U type XHHW condos 600 volt Cerro. The stamp is very hard to read and this is what I came up with reading several stamps along the wire. Can anyone tell me what wire I have? Have I been correct in assuming it is 6 gauge?

 

It's aluminum SEU with two #4 phase conductors with one #4 neutral that is concentric.

 

Thanks!

So its 4 gauge wire instead of 6 gauge? I assume thats what #4 means? I am researching now but figured I would ask. If so, Its saying I have two coated #4 wires and one bare #4 wire. Since its aluminum I assume it would be rated for a 50A breaker? Not a 60A or the currently installed 40A?

 

Number 4 aluminum is rated at 55 amperes but code allows you to go to the next higher standard breaker when the rating is in-between standard breaker sizes. So, yes, you CAN go to the 60 ampere circuit breaker.

More of a concern is that you have a three-wire feed to a sub-panel. This was once fairly common but not so today.

 

That was wrong when it was installed, it should have been SER cable with 3 insulated and 1 bare ground.

Probably not, but it never hurts to do a load calculation. You appear to have 20 KW of emergency electric heat in the air handlers, 10 KW in each air handler. Homes with 20 KW electric heat usually have a 200 amp service. Your 200 amp service was set up under older codes. Back in those days a 200 amp split bus panel would have a 100 amp lighting main which is what your 40 amp house subpanel appears to be. I agree with replacing your main panel with a 200 amp main breaker panel and then replacing the feeder to the house subpanel with SER cable rated for at least 90 to 100 amps.

Considering the age of the meter socket I would also look strongly at replacing it. A local contractor will know the rules of the utility company. In my area if you touch the service you must upgrade the meter socket to a new lever bypass meter socket and upgrade all grounding to current code.

 

Thanks for the detailed info! The house was built in 1980 so I am sure the codes have changed a good bit since then. The inspector when I purchased the house said it was wired correctly for the time period. We are looking in to getting someone out at the end of the year to install the main panel and what ever else is required by my local code. I want to go with a 200A main panel and a 100A feed to the sub panel. I feel this will be the best option for me at this moment. For the meantime, I think I will install a 60A breaker in the main panel for the sub panel feed. That way I can at least dry clothes and run hot water (water heater and well pump) at the same time. It appears that everything is capable of handling 60A (main panel, sub panel and sub panel feed wire).

 

Trying to get this all straight in my head.. Is this close to what I should expect once the new main panel is installed and I need to connect the sub panel with a 100A feed?