100 Amp Service - Installing A/c - Need To Upgrade?

I am installing central air conditioner in our 80 year old house. Debating between one high velocity system or two conventional systems.



We have 100 amp service with an electric dryer, stove and oven. Water and heat is gas.



The HVAC contractor told me that he spoke with the electrician who assured him that we would not need to upgrade service but add in a sub-panel.



Any thoughts?



What are the risks of staying with current electrical service and adding A/C? What are the risks of upgrading to 200 amp with such old wiring? Is one high velocity system better than two conventional systems?



Note I am cross posting based on another question I had in the HVAC forum.



Thank you in advance for all your help.
      


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Similar Topics From Forums

I have 200 amp service with a 50 amp service tap to the garage and another 50 amp tap to a small service panel for extra circuits. I have a 70 amp draw for a tankless water heater, 30 amp draw for the air conditioner, a 40 amp draw for the cooktop and a 40 amp draw for a double oven. I want to add another tankless water heater about 50 feet from the 200 amp panel. The new water heater requires three 50 amp breakers. How do I get the necessary service to the new water heater?
      
I'm having quite the time finding an electrician who will quote this.  Just about all of them say that what I need is to upgrade my main panel but I want to install a new main panel that is a part of the meter base outside and make my current 100A panel a sub.   Maybe you people can tell me why nobody seems to want to do this.  Here are a few shots of the existing meter (note what is apparently a 60A base here)






and a shot of the conduit headed underground.  Like most homes built during this era, the conduit makes a right turn underground to enter through the cinderblock, ending up coming into the back of the main panel.  This conduit encloses a 4 wire feed. edit: no, actually it is only a 3 wire feed which is a problem if I want to convert the original main panel a sub.






Here's the existing panel.  It's a 60's era Square-D split panel with a 30 amp sub panel for the finished basement.  Those are low voltage wires to circuit taps for my home energy monitoring system btw.






The reason I don't want to upgrade this panel are as follows:

We won't be expanding the electrical west of this panel any more.  All planned expansion (240v car charger in Garage, planned 3 season room with grid tie Solar on the roof) will be to the east.


Upgrading the panel will require major surgery to the walls.  Due to the way the original basement is engineered there, the walls have an intricate stud pattern behind the existing panel.  I'd pretty much have to rip out a 4' section and redo it to make the access large enough to handle a 200A panel.


Adding additional circuits to an upgraded panel will require an act of God due to the finished basement construction.  There are no raceways for additional circuits.






Based on this, my thoughts were to create a new 200A main panel outside based on something like the GE model TSM420CSCUP loadcenter.  Here's a shot of this panel:






This particular panel has room for three 2-pole breakers in addition to the 200A mains.  I'd add a 100A 2-pole breaker for the existing panel, with the other two reserved for the garage/solar expansions.



The issue with the contractors who have quoted the job appears to be the conduit going to the existing panel.  I'm not sure what's wrong with it but it is apparently not compliant with current code.  Obviously the bonding needs to change, new grounding electrodes need to be driven, and a water pipe ground needs to be established to the new main panel, but what else is required?



I'd like to throughly research all the code considerations here so I can approach a contractor from a more knowledgable perspective then determine the best way to perform this upgrade.  Due to POCO coordination and the need to cut household power for the duration of the job, I have no desire to DIY this one...



So what exactly is wrong with the conduit running from the existing meter base to the existing load center?  Why is everybody telling me that I can't do essentially what I've described above?  What are the relevant code sections that will apply to this job?  Should I be chatting with my AHJ about local considerations now or should I wait until I have the code requirements down pat (assuming the latter here)?
      
Hello All,



First post, working on a complete bare-stud remodel of my home, so I will try to be descriptive enough.  I have a 150 Amp service to the house (which I might upgrade later) with a meter socket and breakers outside.  I am running into the house (more than 10') to a 125 Amp 20 space ML.  I have too many 15 and 20 Amp circuits now for the panel and need to change it out.  The house is rather sprawling, so the rather than tie rooms together in a confusing way, I broke the circuits down per minimum requirements... almost none of them are near capacity.  I am going to run the big stuff back out to the exterior panel/service however I still need more space in my interior panel.  What I REALLY need is just a 40 circuit 125 Amp GE panel but I don't think those exist because (guessing) *most* 40 circuit scenarios need more amps.



What I wanted to do was upgrade to a 40 space panel (only been able to find a 200-Amp).  I realize I am still limited outside by the service and have already run 4/0 aluminum.  I know I am not going to go anywhere near the 200 Amp capacity, I just need the space.  Is this ok?  Any reason I shouldn't use a 200 Amp MB panel? 



Thanks!
      
Hi all

I'm renovating a rental home I bought. It has the original 90 year old fuse panel  and I'd like to replace it with a modern panelboard. Here's a picture of the current setup:







I'd like to demo the inset fuse box cabinet and then mount a new panel on the wall to the left.

The service conduit goes inside the stucco into the building. I'd like to cut it, put in junction box, and a sweep and extend the service to the left to the new panel



I called our electric co. to get the power disconnected and strangely the rep told me "Oh, people usually just work on it hot". Is this true/feasible??



Your advice is appreciated
      
Appreciate any help with this.



Background:



- new to us old house, got three quotes for an upgrade to 200A service plus addition of three new circuits in conduit with receptacles (Chicago area, conduit is code in just about every town around, I have no issue with that);



- existing service to house was overhead, opted to keep it overhead and not bury it;



- the quote says, exactly: "Installation of a 200 amp 240 volt overhead electric service complete with riser, outdoor meter socket with a 200 amp disconnect, 40 position circuit breaker type distribution panel..." etc.;



I understood from discussing the work with the contractor we chose that install overhead service meant to include the work and materials needed to upgrade the line coming from the pole at the alley to the house to handle 200A capacity; paid 50% down on quote;



- the morning the boss and tech show up for the work, boss says we already have a 200A overhead, which I seem to recall the home inspector mentioning months ago before the closing (makes sense because the overhead runs to a single room addition put on several years ago), but boss was the guy who came to the house to quote the job in the first place, didn't mention anything about the existing overhead capacity at the time;



- the work gets done, seems fine; tech left without going over anything with us but whatever.



Final bill matches the quote to the dollar. There is no indication that there were any surprises during the work.



Since the quote says installation of overhead service and they didn't need to replace the overhead lines from the pole I think the final bill should be lower than the quote. The distance from the pole to the riser is about 40 feet.



Should I expect from the wording in the quote that the final bill should be lower than the quote because they didn't have to touch the existing overhead?



About how much lower?



We didn't go with the lowest quote, didn't beat him up on price and the total bill is quite a pretty penny, so I think he would be making good money either way.



I know there is no way for someone to tell me an exact dollar figure here based on a blog post, but I'd like to get some kind of idea so I can start my conversation about the final bill.



Thanks for any help out there.
      
Hello.

my electricity bills have been sky high for as long as i have been keeping track of them (less than 2 years).   i finally decided to try to track down the culprit.  I bought a watt meter to find phatom loads.  I found some and took care of them



However,

The electric hot water tank has got me thinking.  Could this be the cause of high utility bills?  The tank itself is ancient (RHEEM).  By the way it is rented from the utility company.  it is hard to tell the age because there is no date stamp, and the model number does not come up on the internet at all.  If i were to guess, maybe 25 years easily.  It functions in that I get hot water no problem



1.  Is it possible that the electric  HWT consumes way more energy than it should?, and how?

2.  Is there a way to track the usage?  My utility company installed a smart meter last year, and required an upgrade to get a new circiut breaker panel from old fuses

thanks
      
I have read and searched a bunch on wire size and I wondered if you guys could confirm that #2/0 copper is fine to run from the meter base to the panel.  Upgrading to 200 amp service, 200 amp base and 200 amp panel.  From what I gather its ok for service wires at 200 amps, but in other applications its rated for less.  For what its worth, the poco is running #4/0 to the the meter for the new service.
      
Q1-

isn't rigid conduit supposed to bottom out in hub on new service panel? I thought so, installed mine and the threads look fine but only threaded in about 8 turns then stopped. Same on the other end.

Q2-

i'm trying to figure out how to brace my service entrance rigid conduit in my garage wall to my service panel. the conduit is 1 1/2 inch and the studs are 3 1/2 (2x4) so there's no room for cross bracing behind the rmc.i was gonna brace then strap but no room(stucco exterior) any ideas??

Pics are attached any help is greatly appreciated-

Steve
      
Greetings,



I am looking to wire a sub-panel in my barn to support a general workshop.  Loads would include standard woodworking tools (including 220V table saw), welding, air compressor, etc.



The house has 200AMP main breaker and minimal in-house loads.  Dryer is gas, Oven and cooktop are gas.  Water heater is off the oil furnace.  I think the biggest single load is the well-pump and/or fridge compressor.  We do have sporadic toaster oven, hairdryers etc.  Otherwise its just lights, ceiling fans, flat-panel tv, stereo...



We had 4" conduit installed to the barn, so there is plenty of room to pull a big cable.  The entire run from the house panel to the barn totals around 155' (probably less, but rounding up)



My questions a



Can I pull a 100AMP sub-panel from my main house panel as described?


Would 4/0,4/0,4/0,2/0 aluminum service entrance cable be a good choice for this run?  Could I do it with something lighter?


Could I put an additional sub-panel in the garage (about halfway to the barn) by interrupting the run?  The garage subpanel would have a 220V plug for possible welding and/or electric car charging.  Would this require a separate run?


Are there any other considerations I should be thinking about in planning this?




Thanks for any thoughts you can share on this! 



Cheers,



pete
      
Hello Guru's,



Can I throw a  standard 3 prong 110/120 receptacle on a 15A 2P 220v circuit? I need to run that 15A 2 pole 220 to a switch for central AC air handler service. I'd like to run to a switch with and outlet right next to it for service and still comply with NEC Code. This way, if service tech ever needs to plug a vacuum in or some other device, he'll have a something there. Is this possible or is that too powerful for 220v even though it's 15 Amps? Or should I just run a standard 15A 14/2 circuit.



Thanks



~S