Putting in New Meter Main and Breaker Panel


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Old 11-28-14, 11:04 PM
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Putting in New Meter Main and Breaker Panel

Hi,

I'm converting my 125A service panel to 200A. I called the power company to see if the feeders to my house supported this and they said go.


House was built in 1972 in the Portland OR area and has original panel (see picture). The Panel is by the Garage Door to the house with the attached garage so it is about 18 feet away from the meter base, and uses about 30 feet of feeder to get there..

I was going to put in a 40 space 40 circuit Main Breaker Load Center in place of the old panel. Siemens: P4040B1200CU

Right now there is a 30' run of 2 AWG Aluminum wire from the meter base on the side of the house (No disconnect other than pulling the meter). Only good for 100A at 90c rise.. Hmm kinda scary..

I plan to run 30' of 4/0 to replace it and also put a 200 amp Meter Main Combo Load Center Siemens: MC0816B1200ESN on the outside of the house..

Currently there is a ground wire at the breaker panel that connects into the copper plumbing for ground.

Any concerns with these panels for what I've got going?

What is the normal strategy when dealing with grounding in this situation? Do you remove the strap from neutral to ground and run 4 conductor 4/0 cable from the Meter Main to the Load Center? Do I need more grounding rods? Do I connect them to both panels? Which panel does ground connect to neutral in? The Meter panel doesn't have a separate bus-bar for neutral and ground..

Thanks,

Jeff
 
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Old 11-28-14, 11:44 PM
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My suggestion would be to a outside panel and put the new panel directly under the meter. You could then use the existing panel as a subpanel. In fact you could install a new mast, meter socket and panel next to the current meter while you still had power to the house. You could take your time and not stress over the unexpected. You could have everything set then just call the power company to move the drop to the new panel. Have the new feed to the old panel ready to go already hooked up to the new panel and run to the old panel waiting on the swap to connect it.

I
 

Last edited by ray2047; 11-29-14 at 09:48 AM.
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Old 11-29-14, 05:18 AM
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No need for a main breaker in your new panel if there is one in the meter combo.the ground connection location is normally dictated by the POCO,are you on city water? if so you will a #4 cu or #2 Al from the supply side of the water meter,the ground and neutral connect together if that is what the POCO wants ,you will need 4 conductors between the 2 panels.
Geo
 
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Old 11-29-14, 06:49 AM
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You are going to see if the power company will allow a meter main. Check their list of approved equipment.

If allow the meter main will be where the grounding and bonding take place. The old panel will then need to be feed with 4 wires and the neutrals and ground separated.
 
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Old 11-29-14, 07:01 AM
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Why do you think you need to upgrade the service?
 
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Old 11-29-14, 07:39 AM
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Thanks for the replies everyone! I'm in Portland OR, not Houston Tx btw.. I want to be able to upgrade my kitchen and do an addition, so that is the reason for the new panel/service..
 
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Old 11-29-14, 07:51 AM
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I'm in Portland OR, not Houston Tx
One of the first things you need to do is contact the local building department to see if they will allow you, as a homeowner, to do this work yourself. Many areas will allow a homeowner to do their own electrical work, but not replace a service. If they will allow you to do this yourself, find out what version of the NEC they have adopted. Then you'll need to contact yout local power company and get a copy of their service tules and a list of approved service metering equipment. Most power companies now have this information online.
 
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Old 11-29-14, 08:24 AM
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Here are some pictures which should help show what I'm doing.. You can see the House where I've done a section of the garage to show the service entry and panel location relative to the house.. Also the existing meter and closeup of it in the photo relative to the other utilities in that area.

I called the power company and told them that I wanted to update to a 200 amp service. They said I need to expose the existing feed and then mount a new panel with a 3" PCV conduit down to the same area as the existing feed. They will come and do the rest to hook it up to the new panel.. I just need to get everything ready to go and figure out how I'm going to do the transition..
 
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Old 11-29-14, 08:45 AM
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Old 11-29-14, 09:12 AM
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Name:  Fig 7-4.jpg
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So this is the figure in the 2014 service requirements.. My current panel is 10 inches from a window, On top of the gas line and 22 feet from the corner of the garage. I'm guessing I need to move it over closer to the corner of the garage and comply with the new code..
 
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Old 12-30-14, 10:51 PM
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What are my options for connecting main breaker with a 100 amp service?

There is basically #2 AL wire feeding the meter base.

My disconnect has 4 ganged 100A breakers for the disconnect at the meter base. Can I pull the wire out of two of them to make an effective 100A disconnect?

Can you just ignore that the incoming wire won't handle 200A and you haven't changed any loads on the house, so just don't plug in all the space heaters and vacuums you own at the same time and leave the 200A breakers inline with substandard secondary feeder wire until I actually increase the load?
 

Last edited by zootjeff; 12-31-14 at 12:45 AM.
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Old 12-31-14, 12:24 AM
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There is basically #2 AL wire feeding the meter base. Tomorrow I'm going to dig it up to the street and see if there is a splice to something thicker. But if there isn't and I have to run a conduit all the way to the transformer (bore a hole and pull a new conduit 200ft). What are my options for connecting it back up while waiting? I want to update my meter base and breaker panel and start using it, but it will take some time to figure out how to get the conduit all figured out..

Generally, around here, the power company will size the service drop to a dwelling to what *they* expect your load to be, as well as their transformer size. They will most likely leave the existing #2 in service cable in place. I've seen firsthand services as large as 320A fed with #2 Aluminum and a 15KVA transformer.

DO NOT dig up the existing cable. It is power company property, unfused, and illegal for you to mess with. You can get yourself killed or in jail.:NO NO NO:
 
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Old 12-31-14, 05:39 AM
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The feeders will need to be upgraded to the size of the breaker or disconnect ahead of them. You cannot leave a 60 amp feeder and install a 100 amp breaker to protect it.
 
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Old 12-31-14, 05:03 PM
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Can I take my ganged 4space 200 amp disconnect and remove two of the feeder wires from the meter to make it a 100amp breaker? This would be until the feeders are updated..
 
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Old 12-31-14, 06:18 PM
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I can't picture what you are trying to do.
 
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Old 12-31-14, 06:43 PM
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The combo meter main MC0816B1200ESN has 4 ganged 100 amp breakers. This is back feeding the bus bar that feeds the 4/0 SER to the new breaker panel.. See the pictures at the start of this post.. If you disconnect 2 of these breakers (1 red wire, one black wire) you no longer have 2 100 amp breakers in parallel for each tap of 240v, you have would just have 1 100amp breaker for each tap. But you'd leave the others still ganged but not connected. You would cap off the wire until the point the feeder to the meter is updated. I could use the new panels, have a 100a service with my 200 amp equipment..
 
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Old 12-31-14, 07:03 PM
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The combo meter main MC0816B1200ESN has 4 ganged 100 amp breakers.
Can you provide pictures of this? I have never seen 4 - 100 amp breakers used as a 200 amp disconnect. I don't understand why you are even considerinjg altering it. I'd go ahead with my 200 amp service plans. The #2 aluminum service lateral is no big deal, if it needs to be upgraded, the power company will upgrade it, but it is usually the customer's responsibility to inform the power company of any planned additions to the load.
 
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Old 12-31-14, 07:32 PM
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Here is a picture attached. Name:  Breaker detail.jpg
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No "modification" Simply pull (and cap) one red and one black wire. Instant 100 amp service..
 
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Old 12-31-14, 07:50 PM
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I thought the NEC specifies #2 Al for 100 amps at 90c rise. Are you saying the power company doesn't have to abide by this particular guideline? Won't the wire overheat if you pull 200 amps and melt before a 200a breaker could trip?
 
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Old 01-01-15, 12:22 AM
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Power companies use different sizing and ampacites for their wires. The are not under the NEC.
 
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Old 01-01-15, 05:03 AM
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I wonder how much the wire can tolerate in the dirt. At 200 amps that is 17v of drop over 170 ft of #2 al wire that is about 20watts per foot of pair dumped into the air or ground..
With 4/0 it would be 5v of drop over 170 ft or 6.2 watts per foot of pair dumped into the ground or air..
 
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Old 01-01-15, 06:30 AM
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I just did a load test of my existing house.

I measured the voltage at the panel in the morning with everyone but myself asleep. I measured the 240v lugs at my breaker panel. It is 170ft from the transformer and 30 feet from meter base to panel. So I'm using 200ft for the calculations. (I know for a fact I have #2 AL for all 200ft)

I used my electric dryer for this test. It is a Samsung 5400W unit from 2008. I turned it on high on a timed cycle and then did the measurement before it could throttle.. I measured the voltage and then threw the breaker to get the delta.

Dryer Watts (based on nameplate): 5400
Dryer Amps (based on nameplate): 22.5

Voltage with Dryer On: 243.00
Voltage with Dryer Off: 245.13
Voltage drop result for this test: 2.13V
Calculated ohms for 200ft pair (down and back): 0.0946 ohms
Calculated ohms/ft/pair: 0.000473

If I used this for a 200A service and a 170ft run (xformer to meter), it would be
18.933 watts/ft/pair loss into the #2AL @200A
228.9V at the panel (based on 245V open circuit) @200A
6.7% transmission loss from transformer to the meter panel @200A

This cross checks with some online data regarding voltage drop and wire resistance:
Voltage Drop Calculator
dc Resistance of Electrical Cable Conductors


Anybody know how this jives with power company rules of thumb?
 
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Old 01-01-15, 09:05 AM
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Are you saying the power company doesn't have to abide by this particular guideline?
Utilities follow the National Electric Safety Code.

Won't the wire overheat if you pull 200 amps and melt before a 200a breaker could trip?
Where are you getting all the new load? You have 125 amp service now so your load is probably something under 100 amps. If you are doubling your load it is your responsibility to provide increased load information to the power company. They will increase the lateral size (maybe transformer too) if needed based upon your total load. Yes, #2 aluminum would likely fail if subjected to a load of 200 amps. If you provide all your added load information to the power company, it will be their responsibility if the #2 or transformer fails. Don't provide the information and you may get a bill for repairs.

I'm converting my 125A service panel to 200A. I called the power company to see if the feeders to my house supported this and they said go.
People upgrade to 200 amps everyday with no problems because generally they aren't adding substantial new loads. When you called the power company, someone should have asked you about new loads.
 
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Old 01-01-15, 10:01 AM
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I have been working with the power company and they assigned a designer to me. He said that if I am to increase my load significantly I will need to hire a horizontal boring contractor to put in a new flexible 3" conduit from my meter to the transformer 170ft away. In the past I've called and they said just put a 3" long sweep into the ground and you are done. The extra load is future provisioning for an addition. Please see the attached picture for what I have now and what I would be proposing..

So if it costs thousands of dollars to bore a new conduit, I'm trying to explore my options for not doing that part yet and just update the meter base and panel so I can do things like put in the car charger, run a new garage circuit, etc..


That is why the idea of installing the 200amp panel, disconnecting half the main breakers so that it is a 100 amp effective breaker, and then I've protected the #2AL out to the transformer and I don't get the "large bill" from the power company for repairs, and then when I do bore the conduit and do the addition and kitchen remodel, I can simply re-connect the main breaker wires below in this thread and then I'm covered and protected. I'm trying to figure out if there is something wrong with this where there is some code somewhere that says "you can't do that" because someone sued someone once and now there is a line item preventing it..



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Old 01-01-15, 06:32 PM
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So if it costs thousands of dollars to bore a new conduit
Directional boring and pulling in a 3" conduit can be done for a couple thousand.

That is why the idea of installing the 200amp panel, disconnecting half the main breakers so that it is a 100 amp effective breaker,
I didn't see 4 - 100 amp breakers, but I did see 1 - 200 amp breaker that was parallel fed. I wouldn't mess with the meter main and just install it taking 200 amp wiring to the 200 amp subpanel. If you want to be ultra careful to not overload the #2 aluminum undeground feed to the service, install a 2-pole backfed main breaker on the bus and connect the subpanel through that breaker.
 
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Old 01-01-15, 07:10 PM
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It really looks like the 200 amp breaker is constructed of two, 2-pole 100amp breakers. There is an air gap between them. The sticker spans all of them and makes it look like a single breaker. It says parallel connected I wouldn't break the sticker, or remove the pole that connects the 4 switches together, I'd simply disconnect their feeder wire on the upper half.

If I took the other approach how would I go from a 2 pole 100A main breaker to the 4/0 going to the subpanel.

It really seems like loosing two screws and capping two wires is the KISS solution. Is it not allowed?

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Last edited by zootjeff; 01-01-15 at 07:48 PM.
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Old 01-02-15, 08:49 AM
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It really seems like loosing two screws and capping two wires is the KISS solution. Is it not allowed?
Have you contacted the AHJ and asked if they would allow you to jerryrig the metermains yet? If you are going to do this job, my rcommendation is to do it right. If your responsibility is to install the new conduit, I'd ask whether it must be bored and pulled in or if a traditional underground conduit installation would be allowed. Your contractor needs to be involved in this discussion.
 
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Old 01-02-15, 09:50 AM
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I've run this idea by the utility and they said, "I don't know, ask your county inspector". I've been trying to reach both the lead and assigned inspector for days, but apparently while I'm off on holiday break, so is everyone else, hence the going to the online forums with my crazy ideas..

There is so much pavement and sidewalks that a horizontal bore would be needed. I have two contractors I'm working on lining up, but again, waiting on the utility for this too because he was going to draw up the details around the transformer that the contractor needs to quote..
 
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Old 01-02-15, 09:54 AM
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If messing with the main breaker is "frowned upon". What about pulling the 200 amp ganged breaker and putting in a 90-amp 2-pole in its place, I'd have to cap the two empty spaces, and still cap the other parallel wires... But is the issue that I'm touching the factory panel at all, or is it the confusion around a breaker that says 200A from the outside really only being 100A?
 
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Old 01-02-15, 10:31 AM
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What about pulling the 200 amp ganged breaker and putting in a 90-amp 2-pole in its place,
No need to mess with the main breaker. Joe already covered this:
If you want to be ultra careful to not overload the #2 aluminum undeground feed to the service, install a 2-pole backfed main breaker on the bus and connect the subpanel through that breaker.
 
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Old 01-03-15, 06:58 AM
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If messing with the main breaker is "frowned upon". What about pulling the 200 amp ganged breaker and putting in a 90-amp 2-pole in its place, I'd have to cap the two empty spaces, and still cap the other parallel wires... But is the issue that I'm touching the factory panel at all, or is it the confusion around a breaker that says 200A from the outside really only being 100A?
I see another way to accomplish what you are after that I would consider much more acceptable. The meter/main you have now would become your main panel with the existing backfed 200 amp breaker and feed-through lugs. The 200 amp breaker protects this main panel. Install a 2-pole 100 amp breaker on the bus to feed the branch feeder that will feed your new 200 amp panel which will be a subpanel. This new 200 amp subpanel in your house doesn't need to have a main breaker, but it is also acceptable if it does. Go ahead and run 4/0 Al SER cable (4-wire) to the subpanel. The 4/0 conductors will not fit the lugs on the 100 amp breaker so you'll either need to install pin connectors reducing the 4/0 Al to #3 Cu to fit those lugs or reduce the 4/0 to the smaller size using Polaris pre-insulated connectors. The 100 amp breaker will now keep you from overloading the #2 underground lateral. Later you can move the 4/0 conductor terminations directly into the feed-through lugs at the meter/main panel combo after the service lateral has been upgraded.
 
 

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