Overall Shop/House Power System..

[sponaugle]

I realized after I posted in my build thread that there is a dedicated subgroup for electrical questions, so I'll put this question here where it belongs:

I would love to hear some feedback on my overall electrical plan, and in particular anything I am overlooking in the garage/shop area. Fundamentally I am ok with overbuilding a little bit, as electrical is in wall, and the cost difference is very small compared with the overall cost. Of course there is no reason to waste on things that will never has use as well.

A couple things of note:

(1) I don't actually need a primary 600 amp service based on my current load calculations, but I am making a 600 amp primary service possible (the underground cable and conduits are 600 amp capable). We could use a standard 320 meter and almost certainly be fine, especially given the additional dedicated 200 amp meter for EV. A total of 800amps is probably overkill.

(2) On the EV charging, those plugs are on a dedicated separate 200 amp meter as that allows that meter to be on a special rate plan that does time of use charges. If you charge your EV between 10pm and 6am, the cost per kw is 4.2 c/kwh, which is about 1/3 the normal price. The only restrictions of a 2 meter/meter rate setup is the EV meter can only be used for EV charging.

(3) Heat is natural gas, but there are 2 furnaces, 2 ACs, plus a dedicated AC for the server room, and gas heat for the lower shop level. Aside from EVs, the biggest power draw would be the induction top, the infrared heaters, and the server room.

(4) I have not done the plug layout on the shop, but that will come next. Since there is a panel in the garage, it will be easy to do many home runs so plugs don't share breakers very much. One thing I learned is that you never know how power usage will cluster, so I prefer in a case like that for the plugs to not share breakers where possible, or at least keep it to a minimum.

The build thread for the entire project is here:
https://www.garagejournal.com/forum/showthread.php?t=409988
and that provides some good context on the overall project.

Happy to hear any comments, criticisms, etc!

Jeff

 

[matt_i]

A lot of load comes from qty 2 * RV plug @ 80A.

I don't own one so I don't know what's involved but that seems like a lot of load. Don't most of them run off a 30A twistlock?

Also how are you using RS485 comm protocol to limit the current that can be drawn? is that a feature of the Tesla, to communicate via "data" about what the car "needs" so they can charge sequentially, or is it something within the meter itself that subdivides current between circuits? Just curious about how it works.

Will your utility give you a 600A single-phase service with the opportunity to sell considerable electricity or do they put a cost on providing the wiring & equipment for that much ampacity?

 

[sponaugle]

A lot of load comes from qty 2 * RV plug @ 80A.
I don't own one so I don't know what's involved but that seems like a lot of load. Don't most of them run off a 30A twistlock?

Yes, and I don't even own an RV. These are just external plugs for general purpose stuff I might come up with. Those boxes have a standard 240/50A, plus a Twistlock 30A and a 120/20A. In reality those could be driven from a 50Amp breaker, as I would never need the 240/50 and the TT.

Also how are you using RS485 comm protocol to limit the current that can be drawn? is that a feature of the Tesla, to communicate via "data" about what the car "needs" so they can charge sequentially, or is it something within the meter itself that subdivides current between circuits? Just curious about how it works.

Yes, that is a feature built into the Tesla charger. They can be configured to share the same circuit. Since I am planning 100A for those groups, 2 50A chargers would not need the communications, but if I had a higher current charger they would need that.

Will your utility give you a 600A single-phase service with the opportunity to sell considerable electricity or do they put a cost on providing the wiring & equipment for that much ampacity?

Getting a 600amp service is pretty straightforward. I have a dedicated transformer, and that would probably get upgraded, but other than that the only cost is the thicker buried wire, which I am going to do either way.

Jeff

 

[Krang]

I've been following your home build on FB as you post updates, but this is a much better platform for details. Stoked you are on this forum Jeff.

 

[sponaugle]

I've been following your home build on FB as you post updates, but this is a much better platform for details. Stoked you are on this forum Jeff.

Excellent! Yea, Forums are so much better for this kind of thing, especially with the embedded text and pictures, and the quoting.

Jeff

 

[sberry]

Quite a plan. I have 400, if I was to do it again might try to squeeze it in to 200 to make generator power easier but,,,,, that is another matter. You definitely have room. I might be tempted to work something out to make additions easy, add as needed to some extent.
Btw, cloths dryers are 30A and welders use 6-50 plugs. Change the air comp to 40A service, actual load would be a bit different. Same with a lot of stuff, load different than the circuit its on. This doesn't appear to be a short cut outfit, get a 5 hp 2 stage comp right off and be done if you want to do real work with it.

 

[sponaugle]

Quite a plan. I have 400, if I was to do it again might try to squeeze it in to 200 to make generator power easier but,,,,, that is another matter. You definitely have room. I might be tempted to work something out to make additions easy, add as needed to some extent.
Btw, cloths dryers are 30A and welders use 6-50 plugs. Change the air comp to 40A service, actual load would be a bit different. Same with a lot of stuff, load different than the circuit its on. This doesn't appear to be a short cut outfit, get a 5 hp 2 stage comp right off and be done if you want to do real work with it.

Yea, I changed the air compressor and the dryers, as well as the lifts (which are 30amp not 20 amp). One of the reasons for having a dedicated panel in the shop is to make adding more higher amp devices easier.

Both my MIG and TIG welder are 14-50R plugs, as I have neutrals to all of the 240V outlets. Neither device needs that, but in case there are devices that do, so I like the 14-50R for that use case.

I do need to figure out what I am going to use for a compressor. Interestingly enough I use the compressor less than I have in the past, in part because of the excellent lithium battery tools that are available. It is still a valuable resource for lots of things of course.
Thanks for the help!

Jeff

 

[TRWham]

I see you are providing mostly 15 A circuits for household receptacles, but there are several areas that must be served by 20 A circuits that only serve those areas. Laundry rooms, bathrooms, and garages must each have one or more 20 A receptacle circuits, and the countertop receptacles in the kitchen must be served by two or more 20 A circuits (but those can have other kitchen outlets on them). Article 210 in the NEC has all the details and is available online for free.

 

[sberry]

I make recepts separate from lights, put all the 120v recepts on 20. Yes, someone obviously messed with the welders, all the stuff that comes factory cord and plug comes 6-50.
I will agree that a lot of air use has dwindled especially for mechanics. 5 hp is standard as suffecient for auto body, sanding, we use it for wire wheel too.

 

[sponaugle]

I see you are providing mostly 15 A circuits for household receptacles, but there are several areas that must be served by 20 A circuits that only serve those areas. Laundry rooms, bathrooms, and garages must each have one or more 20 A receptacle circuits, and the countertop receptacles in the kitchen must be served by two or more 20 A circuits (but those can have other kitchen outlets on them). Article 210 in the NEC has all the details and is available online for free.

Yes, that was a lack of detail on the plugs to breakers layout, as there are a number of normal in house plugs that would need 20A breakers, as well as a number of dedicated circuits. I changed the diagram to reflect a mix of 20A and 15A for standard plugs, and I will update that once I get the complete plug layout finished. Good catch.

I make recepts separate from lights, put all the 120v recepts on 20. Yes, someone obviously messed with the welders, all the stuff that comes factory cord and plug comes 6-50.
I will agree that a lot of air use has dwindled especially for mechanics. 5 hp is standard as suffecient for auto body, sanding, we use it for wire wheel too.

All of the lights are seperate breakers from plugs, but that may have not been clear in that diagram. The welder plugs were changed by me because all of the outlets in my current shop are 14-50R, which was done on purpose so that there is a neutral at every 240V outlet. That increases the flexibility of the plug if a higher current 120V source is needed at a very minor cost increase.

I have updated the diagram as well -

 

[sberry]

Use of 120v would call for additional overcurrent protection added to the circuit. Use of a recept other than a welder also calls for full 50A wire. When the 14-50 is used it becomes a range recept. (Think rv uses the same) This isnt all a big deal, personally would rather have the correct plug on the machines. ( not that I havnt done it other ways in the past) just prefer to keep it standard with the plug listed for the machine.

 

[jeepxj]

What kind of panels are you actually speccing to go in anyways?

leviton load center is super nice for a clean install.
https://www.leviton.com/standalone/LoadCenter/


I wish they made a "smart" panel where you could get power consumption breaker by breaker. Ability to turn on and off via local net.
Something like this but with arc fault - https://lyntec.com/remote-control-breaker-panel/

 

[sponaugle]

What kind of panels are you actually speccing to go in anyways?
leviton load center is super nice for a clean install.
https://www.leviton.com/standalone/LoadCenter/

Those load center's are neat, however I wouldn't want to risk putting them in to only have them discontinued a few years later. If there were out for 5 years and had good traction it would be a cool option! I have not spec'd panels yet, but I'll work on that this next week.

I wish they made a "smart" panel where you could get power consumption breaker by breaker. Ability to turn on and off via local net.
Something like this but with arc fault - https://lyntec.com/remote-control-breaker-panel/

Oh yea, so do I!. I will have load measurements on every circuit however, using probably four of these:

http://www.brultech.com/greeneye-commercial/.

I have a few of these in my current house, and they work well. Having load data on every circuit should me cool for some home automation tasks.

Jeff