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hlmccarter · Mar 6, 2007, 07:10 PM

I was told when we purchased our house that it had 200 Amp service which it appears to be; however, the top of each bus bars only has 60 Amp breakers for the Main shut offs. Is this normal? Each bus bar is connected to a hot wire (one red and one black) and then the two 60 amp breakers are connected with fat wires to each other. Anyway I don't ever do more than minor electrical work, but this seemed a bit odd to me and wasn't sure if it was ever done and more importantly and explanation on why please!

Any input would be great.

nmwirez · Mar 6, 2007, 11:23 PM

Originally Posted by hlmccarter

I was told when we purchased our house that it had 200 Amp service which it appears to be; however, the top of each bus bars only has 60 Amp breakers for the Main shut offs. Is this normal? Each bus bar is connected to a hot wire (one red and one black) and then the two 60 amp breakers are connected with fat wires to each other. Anyway I don't ever do more than minor electrical work, but this seemed a bit odd to me and wasn't sure if it was ever done and more importantly and explaination on why please!

Any input would be great.

Your description is not clear to me. Locate where the meter is and see if it has a disconnect breaker. Then follow the meter conduit or cable interconnection to the panelboard.

The panelboard may be a MLO (main lug only) hookup on top to the bus bars lugs along with one neutral cable in the panel. A 200 amp service connection requires a 2/0 awg copper or 4/0 awg Aluminum from the meter to a disconnect breaker. Does any of this match what you have? Nm.

tkrussell · Mar 7, 2007, 03:36 AM

Can you provide a picture of the opened panel with the wires and these breakers you mention?

hlmccarter · Mar 7, 2007, 05:14 AM

Originally Posted by tkrussell

Can you provide a picture of the opened panel with the wires and these breakers you mention?

Hopefully these pictures help. The first is the overall panel and the 2nd is a zoom in on the two hot wires and the 60 amp breakers in question. Thx for your help everyone!

http://www.fileden.com/files/2006/9/...4/DSCN1444.JPG

http://www.fileden.com/files/2006/9/...4/DSCN1443.JPG

tkrussell · Mar 7, 2007, 10:17 AM

OK I give up, what are those two 60 amp breakers for? They certainly are not the main for this panel, this is a MLO, Main Lug Only panel, as suspected by nmwirez. And as he mentions there should be a Main Breaker at the meter, or somewhere upstream of this panel.

The two heavy black and red cables coming in from the large cable at the top center should be the incoming hot feeds to this panel.

Actually appears that the wires leave the breaker on the left, go up over and under all the breakers in the panel, exited the bottom, and connect to the breaker on the right.

After doing a triple take, I am sure this is what I see, and I have absolutely no idea why.

Every day I thing I have seen it all, then comes along another picture of something wacky.

I cannot come up with any purpose for this arrangement. Can you unplug all the other breakers to see if what I think I see is correct? These two 60 amp breakers and connected cables should not be there and should be removed, unless someone can give me a reasonable answer why they are there and should remain.

hlmccarter · Mar 7, 2007, 11:15 AM

Originally Posted by tkrussell

OK I give up, what are those two 60 amp breakers for? They certainly are not the main for this panel, this is a MLO, Main Lug Only panel, as suspected by nmwirez. And as he mentions there should be a Main Breaker at the meter, or somewhere upstream of this panel.

The two heavy black and red cables coming in from the large cable at the top center should be the incoming hot feeds to this panel.

Actually appears that the wires leave the breaker on the left, go up over and under all the breakers in the panel, exited the bottom, and connect to the breaker on the right.

After doing a triple take, I am sure this is what I see, and I have absolutely no idea why.

Every day I thing I have seen it all, then comes along another picture of something wacky.

I cannot come up with any purpose for this arrangement. Can you unplug all the other breakers to see if what I think I see is correct? These two 60 amp breakers and connected cables should not be there and should be removed, unless someone can give me a reasonable answer why they are there and should remain.

You are right those breakers are connected and I would have absolutely no idea as well. I'll look for a main cutoff but I really don't think there is one outside. If there isn't common sense would seem that I should indeed have a professional replace that panel. What started this all was I just wanted to add a few more circuits and that panel is tapped out of room so I was just going to use some of those double breakers to get the room needed to add them.

From the wiring do you think you can confirm if it's a 200 amp service or possibly less? Is there a way to test the amperage with a multimeter or something?

tkrussell · Mar 7, 2007, 11:22 AM

The two heavy feeders I see do appear to be #4/0 SEU cable which is 200 amp rated.

I did not get into before, but maybe should now, that this is a three wire feed, and if there is a Main Breaker, and hopefully there is, upstream, then the cable should be a four wire, with an insulated neutral, and a separate bare or insulated ground.

EDITED TYPO 2:16PM Changed 20 to 200 amp

hlmccarter · Mar 7, 2007, 11:48 AM

There is a ground wiring in the system, but it appears to be added after the fact. The wiring from the source does indeed have two hot wires and then what appears to be aluminum neutral wire that is broken down into several strands.

If there is no main upstream would you recommend replacing the panel? And also from what we have talked about it seems like I could pull those 60 Amp breakers since all they appear to do is bridge the two hot buses, which would give me the room in the panel I need to add circuits. Bad idea?

tkrussell · Mar 7, 2007, 12:36 PM

FYI I went back and edited my typo from 20 amp to 200 amp in my previous answer.

No, good idea to pull out those breakers, not sure what someone was trying to do, but does not matter, pulling them out should have no effect on the operation of the panel, and will free up 4 pole spaces for you.

I see the copper ground, but I assume that goes to a grounding electrode, such as a ground rod.

If there is a Main elsewhere, then the bare neutral cannot remain. If there is no Main elsewhere, one needs to be installed, which can be remote or in the panel.

Changing the panel may be a good idea, due to age and the rust I see. That type of cable, SEU , is popular for allowing water into panels.Once a breaker gets wet it needs to be replaced per UL and the manufacturer's requirements

hlmccarter · Mar 7, 2007, 12:43 PM

Thx for the info. I do have one more question. What do you mean by the bare neutral cannot remain if there is a main upstream? Are you saying the neutral wire should be replaced? If so isn't that something the electric company would do rather than an electrician?

tkrussell · Mar 7, 2007, 01:02 PM

Once a service entrance feeder leaves a Main Service Disconnecting Means, the Neutral is to be insulated and isolated from the equipment ground, which can be insulated or bare. At the panel the Neutral is isolated from any grounded metal,scuh as the panel back box, and equipment grounds are separated.

The utility usually only provides the aerail cable from the pole to the houise, and the customer owns and maintains the wiring and equipment from that point of conncetion,which is the cable on the house, the meter, feeder from meter to panel, etc. So an electrician hired by the customer handles all of this wiring and equipment.

hlmccarter · Mar 7, 2007, 03:43 PM

I am further complexed. I just tripped those 60 amp breakers and they did cut off power to their respective buses. This just floors me. The next step is to pull out the breakers and see what the bus looks like. How could they kill power to the buses if they are just wired together and the bus is hot?

tkrussell · Mar 7, 2007, 04:06 PM

I bet the bus is damaged or broken, and this was a quick fix. Please pull out all the other breakers so we can see what is going on inside. Do you have a voltage tester to see where the power is coming from?

I had a feeling something weird was going on.

nmwirez · Mar 7, 2007, 04:24 PM

Originally Posted by tkrussell

FYI I went back and edited my typo from 20 amp to 200 amp in my previous answer.

No, good idea to pull out those breakers, not sure what someone was trying to do, but does not matter, pulling them out should have no effect on the operation of the panel, and will free up 4 pole spaces for you. tk, this may be a split bus, I could not tell from the photos I down loaded. I didn't get to see the bottom half of the pan. This was real common in the late 50's, early 60's and seeing the old 2/0 SEU at the top is a pretty good indicator of that era.

I see the copper ground, but I assume that goes to a grounding electrode, such as a ground rod.
If there is a Main elsewhere, then the bare neutral cannot remain. If there is no Main elsewhere, one needs to be installed, which can be remote or in the panel.

Changing the panel may be a good idea, due to age and the rust I see. That type of cable, SEU , is popular for allowing water into panels.Once a breaker gets wet it needs to be replaced per UL and the manufacturer's requirements

Thanks for that info on the change out. I can not believe this panel is not a split bus. It is completely out of character with the way the grounding is applied here. Anyway, the real deal about being a 200Amp is not true. Most real estate home inspectors have little experience in what they see inside a panel let alone open one up.:D

Nm

nmwirez · Mar 7, 2007, 04:33 PM

Whoops! I didn't see you guys posting while I was putting in my comments on the pictures. It is a split buss per the data I just read. Nm

hlmccarter · Mar 7, 2007, 04:45 PM

Ok so nmwirez says it's a split bus. Not exactly sure what that means? Why do the two 60 amp breakers in parallel kill the power to the breakers below them? Here are some pics behind of it opened up a bit...

http://www.fileden.com/files/2006/9/...4/DSCN1445.JPG
http://www.fileden.com/files/2006/9/...4/DSCN1446.JPG

The meter outside is fairly old as well and I got some quotes to replace the whole lot for 1800ish... might be worth it just to have that done and add some safety features to the place.

labman · Mar 7, 2007, 05:13 PM

Still can't see what I was expecting, a cut in the buss between the 60 amp breakers and the rest.

nmwirez · Mar 7, 2007, 05:25 PM

Maybe there is too much traffic on this post. My reply explaining what a split buss is and what the poster needs to do took a little time to write up and it just got bumped offline. Do not think that panel is broken and let me do a post about dog grooming later on. Nm

nmwirez · Mar 7, 2007, 06:03 PM

Originally Posted by nmwirez

Whoops! I didn't see you guys posting while I was putting in my comments on the pictures. It is a split buss per the data I just read. nm

Sorry, My explanation was knocked offline just as I keyed in at the same time Labman replied. Unfortunately my reply carried the two pictures that didn't allow the answer to go through. Who knows.

There are two types of split busses which I do not have time to describe.
If you are going to add more capacity to the existing service I will recommend a more economical approach that may save some time and costs. Nm

nmwirez · Mar 7, 2007, 06:18 PM

Hlm

The easiest upgrade is to do a back to back with a panelboard with a 200a main disconnect. You will need a 200amp safety socket meter box with a drop service mast up through the roof unless a lateral is affordable.

In either case, replace the split panel with a new 20/30 or 20/40 200amp main (SQ D recommended) or match existing brand to save breakers.

A short nipple with insulator bushings through the wall will hook up everything easily. This is one of the most common methods for service entrance configurations and the most quick to install. May ask the bidders for this to reduce costs. All other grounding and bonding requirements remain intact as the split buss panel exists now. 2 ground rods though.
I hope this clears the smoke, nm