Upgrade from 100 amps service/ main panel


Old 02-09-05, 11:44 PM
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Lightbulb Upgrade from 100 amps service/ main panel

My Situation Diagram

Thanks for reading this post!!! Let me tell you about my situation. First of all I'm adding an addition to my small house about 450 sq ft. I have approved electrical plans for the addition as it was planned orginally. I live in South Florida and the addition will be almost all glass facing due South. Hot!!!

I have only 3 empty slots for breakers in my current panel

1.)adding 1-20 amp dedicated circuit to the new AC wall unit
2.)adding 1-20 amp circuit for receptacles
3.)Extending 1-15 amp existing circuit (with very little) for the new ceiling lighting.
4.)Extending 1-20 amp existing circuit for the new GFIC receptacle outside

With the addition above.. the energy calcs per nec tables come out to 99 amps (standard method) total for the house. approved!!! seems cutting it close.

Here's what I need. I currently decided to change the AC wall unit to a 220 vac unit that requires a 20 amp double pole breaker. ( I think this has to be a double size 2 slots)
the others (dryer etc. are in 2 slots)

I Cook and heat with gas here but my current range is about shot and am considering upgrading to 2 electric Convection ovens and keeping a gas cooktop.

As soon as the addition is finished I will be building a workshop/shed and would like to add a 220 vac circuit for a welder and a 20 amp circuit for receptacles. In other words I think it would be easier to add a new panel now while the ceilings are exposed etc...

I have contacted 3 electricians and gotten price quotes. I feel they are too expensive here in south florida and they don't want to do the work the wayI want them to. They want to do the work the Easiest way. I have cleared the way already. removed dry wall exposing the conduit running from outside to the 100 amp panel. I placed plywood flooring on rafters in the attic in the old part of the house to facilitate pulling the 2 new circuits. I added lighting in the attic. the first thing they want to do is add a new panel in the new addition. No thanks.

When I contaced them I told them all I want is a service upgrade/panel upgrade. the minimum bid was $2500 dollars. I'm not asking them to pull the new circuits just the upgrade. rant ...Sorry! Sorry!!
I contacted the POCO and they need a weeks notice to turn off power but will turn it back on that day.. as long as the electrical inspector contacts them.

1.) do Meters and the socket which holds it need to be upgraded?
if maybe... how can you tell?
1.a) Does the POCO have to upgrade their wires to the meter.

at least 1 electrican was planning on replacing it. and one said he would do it by not waiting for the POCO (working hot). I have a GE meter and the first numbers on it are 200CL which makes me think its a 200 Amp meter. More numbers are available upon request. Who would be responsible for the selection of a new meter if necessary? The person at POCO was not very knowledgeable on this. Are meters standard? If you reply please give details on this

2.) It's code here in florida to have the main disconnect outside and the existing one has a 100 amp breaker in it. On shopping at lowes and the home Depot they referred me to an electrical supply house to buy a 200 amp breaker. Is it possible to get a 200 amp breaker and just put it in the existing socket? If not I feel it's no problem to just replace the main disconnect box/breaker and upgrade the existing wiring leading to it up to 3/0 copper. There's a 2 inch conduit from the meter to the disconnect.

3.) Please see diagram. Coming off the main disconnect outside is a small 20 amp breaker for a sprinkler pump. I'm not sure if the main disconnect turns off power to this 20 amp breaker. not up for resetting all the VCR clocks yet!!!!
There is no breaker inside to turn off power to this pump. Does this sound legal?
Can the new main disconnect mentioned above contain secondary breakers in it to cut power to the pump and perhaps a new circuit to the affore mentioned proposed shed?

4.) For the new 200 amp panel inside... is it true that the price between a 150 amp and 200 amp panel, wiring and breakers ..is it true that the price is negligible? I'm a litttle worried that the existing conduit won't fit those new 3/0 copper wires required for the 200 amp panel but I want lots of spaces for breakers. Arc fault, powersurge GFIC etc. and I don't want to short change any future projects by running out of space/capacity. You know swimming pool, 2nd story etc..

5.)Is it OK to have.. say 1/0 size Cu wire for the nuetral? That will give just a little more room in the 1 3/4 " OD conduit.

6.) With a new breaker panel the existing circuits might not come in to the panel far enough to meet the nuetral bar etc.. will it be OK to just pigtail on new extensions to the existing circuits to reach the new breakers etc..?

I'm thanking you in advance for your help in this matter. Sorry for being so verbose. I hope you can read through the lines to help on this matter. The meter and the can are my biggest concern here.

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Old 02-10-05, 05:46 AM
Join Date: Nov 2002
Location: SC
Posts: 171
What kind of conduit is it?? EMT or IMC/Rigid (thinwall or thickwall) Need to know ID. Another ques, how long is the conduit?
Your utility co should be able to tell you your meter size , sounds like it may be 200a, I would install whats called a mobile home panel at the meter, it will have a 200a breaker and 8-12 spaces for breakers, you can put your 20a circuit there. come off the bottom of the lugs to feed your inside panel, you can get a main lug. We need to know about your conduit if you want to reuse it.
Old 02-10-05, 08:26 AM
Join Date: May 2001
Location: Dry Side of Washington State
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<<5.)Is it OK to have.. say 1/0 size Cu wire for the nuetral? That will give just a little more room in the 1 3/4 " OD conduit>>

I've never seen 1-3/4" conduit. Sure it isn't 1-1/2?

If you use copper conductors: 2-2/0's - hot. #1 - Ground (Neutral). #6 AWG copper equipment grounding conductor.
Old 02-10-05, 08:38 AM
Join Date: Nov 2002
Location: SC
Posts: 171
This is what I was getting at Thinman, 2 #2/0s & 1 #1 will fit in an 1 1/4 IMC or rigid conduit but not in EMT. If its EMT it needs to be 1 1/2"
Old 02-10-05, 08:42 AM
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Lightbulb The Conduit

Can't find an ID on the conduit but I can describeit . It looks similar to the smaller 1/2 " EMT that carries the circuits throughout the attic. It is shiney and does not give a solid sound when tapped. It appers to be aluminum. It appers to be bent just like the EMT. gentle curves going up, over, out and then down to the disconnect for a total about 24 feet in length. In the middle of the run is a Coupler. Just like the smaller versions. I hope this describes the conduit adequately. Yes I would like to keep the existing conduit.

Old 02-10-05, 08:51 AM
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Lightbulb remeasured conduit

I measured the conduit more carefully. Now I'm talking about the outside width. The smaller 1/2" EMT measures exactly 1/2" on the outside.
The Main Conduit appears to be 1-3/4" .... 2"s (not that big) and Not 1-1/2"s (not that small).

Old 02-10-05, 09:03 AM
Join Date: Nov 2002
Location: SC
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Sounds like 1 1/2" EMT to me, its spot on at 1 3/4". Where the coupling is you should see no threads on the conduit, just screws on the side of the coupling or a big compression nut going around the conduit. Where it attaches to the outside of the box there should also be a type of connector, not just a big nut. The hot wires will be 2/0 copper. The neutral conductor shall be calculated to handle the maximum computed load between the neutral and any hot wire. It generally is smaller. A size 1 copper will be good for 150 amps, 1/0 good for 175a and 2/0 good for 200 A. #1 should work fine for you but the conduit will handle 3 #2/0s and a #6 ground, even though the ground isn't absolutely necessary because the conduit will be ground enough, I would recommend it because I can't see your installation or type of KOs you have in the box. Yeah, I can do this job for less than 2.5K
Old 02-10-05, 09:07 AM
Join Date: Nov 2002
Location: SC
Posts: 171
Oh yeah, if it's an overhead service, the conductors running into the meter will have to be sized accordingly. If it's not a 200A meter now, a new meter base will cost you about $40 or so, we used to get them free from the co-op.
Old 02-10-05, 09:59 AM
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Overhead in the attic the coupler has the 2 screws to hold the coupler in place at the join. When it comes in to the 100 amp (inside panel) it has the typical (winged, knobbed) nut plus a plastic... what appers to be a compression fitting. This turns easily.

where the wires exit from the main disconntct to go inside the conduit has many layers of paint and stucco.but the same gentle curve as inside. The fitting from the main disconnect starts as a flange then a large nut and it and the conduit appers to be threaded there is a little space between the nut and the flange where threads are exposed.

These threads outside are now confusing me!

It is not overhead service. It comes directly up from underground.

this project before the change in the ac unit from a 110 VAC to a 220 VAC had a nuetral load of 79 amps.

2/0 copper makes me happier than the 3/0 I thought was required. The addition of a ground sounds like the way to go. I like to have things done the best way.

I have another call into the POCO about the meter.

Question: sorry about this

So to review the wires for a 150 amp service.
2/0 copper for the 2 hots
1/0 copper for the nuetral or (determined by the biggest load between the Nuetral and and the hot.
6 copper for the ground.
IS this correct?

and for the 200 amp? what would have to change wire size wise. Is the 2/0 copper hots ok for this?

Jedi9 do you live in florida?

Last edited by ITcookY; 02-10-05 at 10:17 AM.
Old 02-10-05, 10:39 AM
Join Date: Nov 2002
Location: SC
Posts: 171
The sizes of wire given and that you have listed are for a 200A service. I'd like to know more about your conduit, still can't tell by your description if it's EMT or not, if it is IMC or rigid, however, it would be 1 1/4 sized and would still carry 2 2/0s and 1 #1, If its rigid you would not be able to add the #6 ground, the conduit would be the ground, if its IMC you would be able to add the ground.
I'd get the electrician out there to check it, tell him you want to upgrade the meter base if nec, install a 200A mobile home panel outside in place of your outside disconnect, run a 200A circuit inside existing conduit to a new panel inside. You can get a main lug panel inside, a main breaker is not required since you have the breaker outside. Tell him to install all new breakers, hook up all existing circuits, and knock off at least $1000 off your 2.5k bid. I don'tlive in Fla.
Old 02-10-05, 11:09 AM
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donduit inspection

Outside where the conduit exits the Main disconnect to go up, in and over I'm giving a closer inspection. I'll be right back.
Old 02-10-05, 11:35 AM
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Lightbulb Conduit

the conduit outside where it exits the main disconnect is not threaded. the flange on the panel (main) has a female threads and into it looks like a short (about 2 inch) piece of male pipescrewed into it. The conduit fits inside this male threaded pipe and a (looks like a compression nut) nut ties the conduit into the short 2 inch piece of pipe. My biggest pair of channel locks can't go around the nut must be almost 3 inchs in diameter. I'm not familiar with IMC. __ metal Conduit.

would the conduit be the same inside as opposed to outside. At the join they apper to be the same. I mean is the EMT rated for outside (assuming the connector is watertight)? Does IMC and EMT use the same type of connectors? Speaking mostly of the join in the attic. This is where the 2 Long pieces of meet in the middle of the run. The connector is just like the smaller ones I have used for the 1/2 inch EMT...

Thanks for all your input!!!

Last edited by ITcookY; 02-10-05 at 11:56 AM. Reason: addon
Old 02-10-05, 11:40 AM
Join Date: Nov 2002
Location: SC
Posts: 171
sounds like emt, going into a box connector, going into a weatherproof hub.
Old 02-10-05, 12:02 PM
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Pulling the wire.

What is the best way to attach and pull the wires from panel to panel? All 4 at once or in stages?

Thanks Jedi9
Old 02-10-05, 12:22 PM
Join Date: Nov 2002
Location: SC
Posts: 171
take one of the existing wires, (try to pull the others out, leave one, if you can't, just cut the others short) strip it back 6 or 8", make a loop. Do the same to your 4 new wires, except cut about 1/2 of the strands off, loop these through the loop in the old wire, twisting the wire back on itself, making it as compact as possible. Tape it up good, apply wire pulling lubricant, pull the old one out and the new ones in at the same time.

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