help in setting up new service
Setting up a new service for a house we are building. The meter is located on the street and the house is located about 100 yards from the meter. I need some advice on how to set this up. The service from the electric company is single phase (two wires).
I was thinking to put a breaker after the meter so I can shut power off when doing work on the line. I was thinking a 100 amp breaker to accommodate power consumption in the house and workshop. Basically just a shutoff box for the whole line.
After that I wanted to run the cable underground to the house which is located about 100 yards from the meter. Not sure what size wire I would need for that run. I wanted to use aluminum wire as it is cheaper.
I will put in a temporary power pole next to the construction site and was thinking to put in another 100 amp main in that box. with two 20 amp breakers with #12 copper wire for a couple power outlets we can use during construction.
Hope this makes sense.
Thank you for your help.
Replies
Where is this house? What is the voltage? will the meter stay at the street after the house is built?
Most utilities around here want the meter on the house, and they pay for/install the service line.
But technically, you need to start with the house loads, and size the service from there.
https://inspectapedia.com/electric/Underground_Electrical_Service.php
including links has some info on your question.
100 amps would range from AWG 2 to AWG 0, (depending on temperature rating of the cable insulation) but the length and voltage drop calls for larger diameter cable 300kcmil the cable type has to be specified for buried use.
Thanks for your reply UncleMike42!
The house is outside Guadalajara Mexico so a little different situation for connections as you might imagine.
Voltage is 110. Two wires, hot and neutral coming from the electric company.
The meter will stay on the street above the property and we have to run the wire to the house after the meter.
I have experience with residential house wiring but have never done anything like this and from reading many articles see this setup is another level that I don't know.
I found an online load calculator and it came up with just under 50 amps for total load. That was adding in everything I could think of that we "might" have in the future i.e. dishwasher, freezer, etc.
I attached pdf of that.
Since the run is long and subterranean and not easily upgradeable, I was thinking 100 amps to provide any future additions such as electric vehicle.
But again, I do not know anything about this so relying on experts like yourself to guide me.
Thank you for the links. Very helpful!
I found a voltage drop calculator online and posted the results as a pdf.
Ok, your calculations for cable size is about what I came up with as well. I will more accurately measure the distance tomorrow.
The other concern I had was how to connect that thick of a cable to a breaker? Do they make breakers that accept that size of cable?
Again, thank you so much for your help here! It is a lot of information to digest but slowly it is starting to make sense.
I just made this diagram to better explain what I am hoping to achieve. Hope this helps and thank you again!
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I might be able to get two phase service ( three wire, two hot, one neutral). I am checking on this tomorrow. Is there an advantage of having two phase vs. single phase service? thanks again
Nice names you guys.
240/120 in this country is standard single phase service. There is no two phase that I know of. Two phase exists but I don't understand it. Three phase service is generally 208/120 although some older services are 240/120 with a stinger leg.
In Mexico services may be different. I have a place in Ensenada with 120 (perhaps 110) service. If you can get 240/120 you'll be much better off. I question your load calculations. They seem to omit any general and lighting loads. You are also pushing the 100a limit. In this country 120 volt circuits seldom exceed 20 amps. Single pole service equipment may be available and standard in Mexico but it isn't here. I know that color coding and grounding differ there. You are going to need to follow local practice which may not correspond to any advice you get here.
Are you going to live there full time?
The phase question is a semantic one. common practice calls the grounded center tap 220 as split phase. or single phase. the hot legs are each 120volts, and are 180 degrees out of phase from each other, so net 240 volts between them.
There was an earlier concept commonly called two phase, with the hot lines 90 degrees out of phase, but this is long gone, and would not work with today's house wiring and appliances.
Yes that is what we get here:
2 wires -120
1 wire - neutral
3 wire total
I am still waiting to talk to the electric company on the service but looks like I can get two power lines with a neutral, 3-wire service.
Just waiting to see what max amp breaker I can put after the meter.
Sorry for the confusion about phases. I misunderstood and thought each power line was a phase. So two power lines being two phase.
Learning as I go here. Appreciate all the comments and help here.
The biggest advantage to 220volt service is that you get twice the power for the same size wire. you also get a wider range of utilities to install (like air conditioner... the electric car might like 220 volt better too. but this all depends on your daily drive. I know folks who drive a Volt, for example and only have a 120 volt charger for it.
I am not what you would call and expert, so make your own informed decisions.
I am a retired electric engineer, but not a licensed engineer.
What is the service the electric company will deliver? does that drawing show 30 amps? you cannot get more than they will provide.
If the cable is rated for underground service use, you do not need a conduit, but it might be a good idea depending on how deep you will bury it, and if you think someone might dig it up to plant a bush or chase a leaky pipe.
Very good point about the electric car!
As noted above working on getting more info from the electric company on the max amperes I can pull.
The service comes in as three wires, two hot (110 volts) and one neutral.
Thanks for the advice on the conduit. I think I'll go with it as the cost is not that much more and gives added protection.
I measured the distance from the meter at the street to the property edge and it was just at 50 yards.
I will update here when I get more info from the power company.
Again, thank you for the help!
So after much research and getting advice from some "experts" at the electric supply, I have put together my plan of attack.
I have attached two photos of the service connection.
I went with #4 copper from the street connection down to the service disconnect which will be 100 amps.
From there I will go underground with #0/0/2 aluminum in PVC for 70 yards to another service disconnect of 100 amps.
From that I will go to a smaller box with four 20 amp breakers going to outlets.
The last part is my temp setup during construction for power tools, a water pump, etc.
Hope that makes sense. It has been a big learning curve and the help I received here was invaluable in helping find my way. Thank you!