200 amp main is full and I need a 125 amp subpanel

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  #1  
Old 02-08-15, 07:13 AM
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200 amp main is full and I need a 125 amp subpanel

Had a new heat pump installed and there is no room in my main panel to connect the 15kw heat strips. They said I need a subpanel. My 200amp service panel is full of tandems as well as 2 60amp double poles for the two heat pumps I have. (Had a sunroom/game room installed a while back with its own heat pump) I also have a 30 amp for the dryer and 40 amp for the range. The rest of the panel is tandems except for one 20 amp breaker. I have received quotes for adding another 200 amp service as. Ive also got aquote to run a 125 amp subpanel from the disconnect I have now. In the past I have added a 125 amp subpanel to a prior rural cabin by coming off the main. In this application there is a 200 amp disconnect right next to the meter that feeds the 200 amp service panel directly on the other side of the wall. I need the 125 amp subpanel to run 50 feet away in order for it to be next to the heat pump outside. Id also like to have a couple of 20 amp breakers in that panel to possibly add some receptacles in the future. Can I simply pull the double 60 amp breaker that is in the service panel now and replace the wiring and install a 125amp breaker to run to the subpanel outside? Another electrician is supposed to be quoting me to replace the existing 200 amp panel with anew panel that has more circuits. Ive been told so many different things that im totally confused! I am in Georgia. Not in any city limits. Any advice?
 
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  #2  
Old 02-08-15, 07:19 AM
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I think the first thing to do is have someone do a demand load calculation to see if your 200 amp service can support the increased load. If it cannot you are looking at adding another service.
 
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Old 02-08-15, 07:58 AM
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I agree with PCboss. I am a little concerned you might be pushing your service adding 15,000 watts of additional load to a service that has 2 heat pumps, range, dryer, and likely electric water heater. Google "load calculation" and see where you are at with the additional load.

On a side note, I see no reason to replace the 200 amp panel with a larger one. If your going through the trouble of replacing it, upgrading to a 320 amp service would be a better call. IMO adding a 2nd service as PC suggested would be a good way to go if you have the room. You also might want to get the power company involved to make sure the transformer serving your home is big enough.
 
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Old 02-08-15, 08:13 AM
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  #5  
Old 02-08-15, 01:04 PM
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Thanks for the help. Ive now had two electricians out here to look at this issue and dont feel any closer to a resolution! One of them did put an amp reader on the disconnect next to the heat pump. Hes the one who quoted me for adding another 200 amp service and for just adding a 125 amp subpanel. Im still waiting on the proposal from the other guy who suggested a bigger 200 amp load panel. Have a feeling I'm getting nowhere. I'm not going to risk trying to add a new service panel myself. Subpanel I can do...service panel, no way!
 
  #6  
Old 02-08-15, 01:20 PM
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According to the load calculator I'm running around 182 amps right now. Guess that means I'm almost maxed out huh? Should I start looking for someone to add another 200 amp service panel at this point?
 
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Old 02-08-15, 01:31 PM
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Sounds like another service is in the offing.

Adding a larger 200 amp panel still only gives you 200 amp of capacity. All it adds is more breaker space.
 
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Old 02-08-15, 01:37 PM
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I'd be surprised if your utility will allow a second service. Most likely they will require that you install a new 320 ampere service; two 200 ampere masts and conductors (assuming overhead service) or a second 200 ampere lateral (underground service) to a combiner box or current transformer box (depends upon the utility's metering) and from that it would split to the existing 200 ampere panel and a new panel which could be anywhere from 125 to 200 amperes. A new meter, either a 320 ampere direct meter or a transformer meter (with the current transformers) will also need to be installed.
 
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Old 02-08-15, 07:10 PM
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According to the load calculator I'm running around 182 amps right now.
I have a really hard time believing that a house that can be heated with 15 KW electric emergency heat could have 182 amps running....without the heat. 15 KW typically would heat a house of 1400 to 1600 square feet, how big is this mansion you have? It isn't unusual to find all electric homes with 20 to 25 KW electric heat all running on one 200 amp service.
 
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Old 02-08-15, 07:22 PM
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I'd suggest finding a second load calculator and see if it agrees with the first.
 
  #11  
Old 02-09-15, 05:31 AM
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Does that calculator take demand factors into account? Sounds pretty high.
Geo
 
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