Knee deep in electrical planning and I'm wondering what you guys think, 100 or 200 amp service? Just to remind everyone, the cabin is a bit over 800 square feet and has a electric water heater, fridge, well pump, but a propane stove. I'm adding a shop that will also periodically run a stick welder and of course the table saw and other wood working tools. Thoughts?
200, you won't regret it but you might going the other way.
No brainer. 200 Amp. I have a 200 amp and now I wished I would have gone bigger.
:) well that was quick. Lol.
With a workshop in the mix, 200, much more reasonable to do now rather than increase or be sorry later. With modern high efficiency lighting and appliances I believe 100 can do a normal house. But a workshop adds a dimension a "normal" house seldom sees.
So 200 to the house and 100 to the shop?
If I'm remembering this correctly, the engineer for the electrical provider is the one that decided we needed 200 amp service. He also said to run every outbuilding off the same service line so we don't end up incurring multiple service fees. Going as far as to say that if we ever exceed the capacity of the transformer they would upgrade it for free.
I am not at all an expert on this, but realistically your house will never draw anywhere near 200 amp, and it's probably relatively rare to exceed 100 amp continuous draw unless you are using an electric oven, stove, water heater, baseboard heaters, all at once.
Just to clarify my last post. Never even considered my useage in the future when I built my house. Yes 200 amp was plenty for the house and the shop. But things change just like life. I added an addition onto the house. Just lights and receptacles which would hardly affect the original or present service. But in that addition upgrade I added a one bedroom apartment. The apartment was to self sufficient having a kitchen and bath. This required an additional range, hot water heater and heat pump. The heat/air conditioner is a mini/split but it does have a compressor. I plan on moving the shop to the garage underneath it. I ran a 100 amp service just to that area. It would have been ideal to have a 200 amp for this. I will probably have to be selective in my consumption once everything is up and running. I have already considered an emergency generator back up separate from the house which has a standby system. A little less convienent but doable with a separate generator.
Here's a real basic question. If the pole to the house is 200 amp is the feed to the shop 200 amp also? Or is it something less? I mean am I feeding 200 amps the outside disconnect under the meter, running wire capable of the entire 200 amps into the house and then, then running wire capable of handling all 200 amps to the shop from the outside disconnect?
I am no electrician but I believe it is possible to exit your 200 amp disconnect to a separate 100 amp service at your disconnect to your shop. That would eliminate running a separate line from the house to the shop. Maybe some may be able to shed some light(no pun intended). ;D
What redoverfarm said makes sense to me too. But I am also not an electrician. ???
Just talked to my future service providers (I love small town USA!). 200 Amp to the meter and they supply the main disconnect and breaker. I can add a 100 amp breaker and run a line to the shop and a 30 amp to the well. Now to figure out if it's a better idea to run shielded cable or lay a conduit. Thoughts?
Quote from: retiredmarine on November 28, 2018, 11:48:00 AM
Now to figure out if it's a better idea to run shielded cable or lay a conduit. Thoughts?
For peace of mind I would run conduit. If something ever did happen it would be easier to pull new wire than to dig up and replace. Lightning has a way of ruining electrical wire.
Now for a unrelated electrical question. Anyone know how to figure out Christmas Tree lights? Swell when they are well. ???
Quote from: Redoverfarm on November 28, 2018, 12:15:56 PM
Now for a unrelated electrical question. Anyone know how to figure out Christmas Tree lights? Swell when they are well. ???
If it's not a fuse in the plug of the light string they are difficult to sort out.
Conduit that is large enough to permit pulling extra wire is nice to have if you ever need to add or replace a line. good to leave a pull cord in the conduit as well.
That makes sense, of course there goes my excuse to buy a backhoe. So if the 200 amp service goes to the meter does that mean the house and he shop both get a 100 amp subpanel each? I mean there's no reason to install a 200 amp panel if it's only going to get 100 amps right?
Sometimes you have to resist the service company a bit on service lines, they (or at least, my) service company seems to prefer direct burial ... I think it has to do with copper gauge and heat dissipation into the soil. A conduit may require a bit more copper, but I prefer conduit even if I have to pay for the upgrade. I also prefer to run PEX water tubing through an oversize PVC pipe. Someday ....
Ask and you will receive. I asked a friend of mine which is a retired Master Electrician and here is his response. Hope this answers your question.
1) You can pull directly from the 200 amp box, IF you have the proper size and type of wiring for the run length and location (ie underground or overhead or in conduit). Local codes will determine what, if any, breakers/fuses need to be in line since it is disconnect to disconnect. If the main 200 amp box is a disconnect with fuses/breakers, and it should be, then it should meet any code. However, the total rated potential draw should not exceed a specified rating of the primary box. Same with the main feed wire.
As an example, you have wiring from the pole to the main, rated for say 500 amp, you are ok there. Your main disconnect is rated at 200 amp. That means (in most locales) that the total potential, factored load might be limited to 300 amp (see below on this). So if you have 200 amp potential to the house and a 100 amp potential to the shop, then you are usually fine, since you would probably never have everything that draws electricity on at the same time.
2) 100 amp box should also have its own fuse/breaker. Each primary box should always have an over-current safety built in, whether required by code or not. Best to have joined breakers instead of fuses, as if one leg trips then both legs trip.
3) Be certain to run the 240v to the secondary box and not just 120v. While in most places running only UF (underground feed) cable is legal underground, I would always run the feed wiring through a grey conduit, just for the protection side.
4) While it is doubtful anyone would say anything, the rule of thumb is the total load at any point (and I'm doing this figure from memory, so it might be different) from a feed location (specific circuit breaker, main breaker, etc) should not exceed 150% of the circuit rating, based on calculated or probable use at any specific time. This means you can have a 20 amp circuit, say for your kitchen, that has a microwave (11amp), a toaster oven (15amp), a mixer (5 amp), and a ceiling light ( 3 amp) all on the same circuit. Obviously if you turned them all on at once they'd trip the breaker. But you could have the microwave, the mixer and light all on, or swap out the microwave and light for the oven and you are still at or below 20 amp. What matters in this is the wire size and the breaker. Since it is doubtful you would have all those things on at once, then their total possible load would be 34 amp on a 20 amp circuit. 150% (some places give 200% as the number and their are other variables too) of 20 amp is 30 amp, so 34 is above that number and may require you to split that kitchen circuit into two 20 amp circuits.
5) Here is one of the other variables. Say you have a 120v microwave. It NORMALLY doesn't run at 100% all the time, it is constantly turning on and off and adjusting its power consumption and use, so it might draw on most loads 50% of the rated capacity. Thus that 10 amp draw (continuous) might really only be 8 or 4 or 2 amp average over time. The national electrical code allows this. A table saw draws more power when cutting than when just spinning. A welder, a drill, they all do the same. Electronically controlled devices adjust their consumption. So the code may well say that a specific device, while rated at 10 amp, only counts as 5 amp. That said, something that uses resistive power, like an electric heater, is either on or off and thus a 1500 watt (12 amp) toaster over, when on, is pulling 12 amp constant.
6) The disconnect and the breaker panel can be the same box. They usually are now.
7) Wire run size - 100 amp service should be run at a size #3 wire. Using this size, at 300 feet, there could be a voltage drop of about 15 volts. So the 240v is now possibly 225v at the secondary box. Size #2 wire negates this. You should also run two hot legs, a dedicated neutral and a separate ground. That said, in many places the dedicated neutral is not specifically required, as they will often use the ground as the neutral. I don't like doing it that way. Run the neutral and you reduce the risk of messing up 120v motors.
Thanks John
Since the main\meter will be 200 amp do I need a 200 amp box in the house? The shop will be on its own 100 amp circuit so it will get a 100 amp panel.
My understanding, and my read of John's response is you can have a 200 amp service, with a 200 amp breaker at that disconnect, running a 200 amp panel in the house, with a 200 amp main breaker and a 100 amp panel, with 100 amp main breaker, in the shop... 150%
I think we're saying the same thing, the electric co is going to set a meter with a main panel below it. In it they are going to provide a 200 amp breaker. I will add a 100 amp breaker for the shop and a 30 amp breaker for the well. In the house I'll hang a 100 amp sub panel. Same sheet of music? I guess I was wondering what the advantage would be to hanging a 200 amp panel in the house?
Quote from: retiredmarine on November 29, 2018, 06:44:09 PM
I guess I was wondering what the advantage would be to hanging a 200 amp panel in the house?
You could isolate the circuits better. I ran out of space on my 200 amp panel and had to start replacing the regular breakers with mini-split breakers. As the old saying goes " You can never have enough". The cost difference is minimal.
Quote from: Don_P on November 29, 2018, 06:36:51 PM
My understanding, and my read of John's response is you can have a 200 amp service, with a 200 amp breaker at that disconnect, running a 200 amp panel in the house, with a 200 amp main breaker and a 100 amp panel, with 100 amp main breaker, in the shop... 150%
Once I run the 200 amp service from the disconnect to the panel in the house do I run 100 amp service from that panel to the shop or does the 100 amp service to the shop come from the disconnect also?
You should be able to run a 100 amp disconnect off of your 200 amp disconnect then to a 100 amp panel in your shop ( which can then run your shop and well) . Then continue from your 200 amp disconnect to your house 200 amp panel. The 100 amp disconnect will only allow 100 amps for your shop.
I think it is confusing referring to disconnects and panels. The disconnect cuts the compete voltage to a main breaker panel. Then a main breaker panel has an additional breaker of the same voltage as the disconnect. I reread a previous post in which you stated the electric company was going to install a 200 amp main panel. They are probably going to put a 200 amp disconnect below the meter. You would come out of that to feed your 200 amp main panel in the house. That way you would not disrupt every circuit to work on something is a particular circuit.
The disconnects are a safety feature so that in an emergency your complete power can be shut down by the fire department without having to enter and find your main panel box.
Some of the rules can seem arbitrary. On my house, If I ran the feed directly through the wall to my panel, I did not need a direct disconnect, other than the one on the panel. But because my meter was offset 18" from the panel (no way to avoid it) I had to install a meter box with an external disconnect. My meter box has a 200A disconnect for the house, and spaces for four breakers outside. I used one slot for one of my HVAC units, and another one (100A) for the barn. I worried a little about the outside disconnect, as a bad guy could cut power to the house prior to breaking in, or kids could shut it off as a prank. It's illegal to lock it in any way.
I ran #2 cable to the barn in 2" gray conduit, and put a separate 1" conduit in the trench for future communications needs such as CATV. Both conduits have a pull string installed in them for future needs. The small trencher that I could have rented would have just barely deep enough, so I rented the big one. Thing is, in our rock-hard clay, the trencher would only work pointed straight down, so I wound up with a 3' deep trench. I think it's safe!
The BO explained to me that rule is for firefighters. If there is not an exterior disconnect the panel is directly behind the meter base. Each jurisdiction/ power company can have its own rules though.
Quote from: Redoverfarm on January 19, 2019, 08:09:57 PM
You should be able to run a 100 amp disconnect off of your 200 amp disconnect then to a 100 amp panel in your shop ( which can then run your shop and well) . Then continue from your 200 amp disconnect to your house 200 amp panel. The 100 amp disconnect will only allow 100 amps for your shop.
I think it is confusing referring to disconnects and panels. The disconnect cuts the compete voltage to a main breaker panel. Then a main breaker panel has an additional breaker of the same voltage as the disconnect. I reread a previous post in which you stated the electric company was going to install a 200 amp main panel. They are probably going to put a 200 amp disconnect below the meter. You would come out of that to feed your 200 amp main panel in the house. That way you would not disrupt every circuit to work on something is a particular circuit.
The disconnects are a safety feature so that in an emergency your complete power can be shut down by the fire department without having to enter and find your main panel box.
I get the confusion using disconnect and panel interchangeably. So let me do this from the beginning and see if we're on the same page. The elec company is going to put in a 200 amp service with a meter and disconnect. Because the elec and well will be installed before the house I'm adding the 30 amp breaker to that box along with a 20 amp breaker for a few 110 outdoor outlets at the base of the disconnect. Then when the house, the next structure to be built, is ready I'll run power to the house (I'm guessing 200 amps). then when the shop is complete, later, I'll but in a 100 amp breaker under the disconnect in the elec company supplied box and run it to the shop. So the lines from the elec company provided disconnect box will supply the house (200 amp) and the shop (100 amp) two lines run at two different times. Are we all saying the same thing?
That sounds a little better. I would check with the power company and make sure what they will be installing. Generally it will be a 200 amp disconnect with maybe one breaker and no additional spaces for additional breakers. You may have to come off of their disconnect with your additional 100 amp disconnect. Then you will need to come off of that for your well & 120 outlets. Is your shop going to be built first before the residence?
Good. I'll double check but I'm pretty sure I remember correctly. They suggested that I place my well breaker and a temporary breaker for construction in the box they place. The house will be built first then the shop. I'll trench to the house then after the shop goes up I'll trench from the electric company disconnect to it. If all that's right then next question. The electric company's box will not be grounded I assume so I'll be doing that out of the sub panel in the house. Correct? Does that mean the sub panel in the house should be bonded?