Wiring to detached - thoughts?

[jpcjguy]

Hi all,

So I had older thread on this located here:

https://www.garagejournal.com/forum/showthread.php?t=277109

After doing more homework with the power company and the local inspection office, I have plan!

Just to make it clear - New service is out - too much $$$

So I have twin 200amp panels in my garage. The largest breaker I can get for the panel is a 125. I talked to the building inspector and he agreed that I can tap into the meter directly and go to an external disconnect and then go along the side of the attached garage (buried next to slab) and then under the house and come out the corner and trench to the garage. Looking at another 200amp panel for the garage. Will have compressor, welder, future lift, and possible future HVAC for lower and attic truss space. Basically want to future proof it within reason.
This leads me to another thought - I currently don't have a good generator solution. Nowhere near the house that is visual friendly to put one. Being able to put a whole house behind the garage would be great - could even be propane based, since it would all be hidden. This would mean "backfeeding" to house. Problem is that I am tapping off the meter - not a panel in the house. Any creative solutions that anyone can think of? Too much work for not enough value? Would the wire size between the garage and the house have to increase significantly, thereby increasing costs to "not worth it" land?

So back to the normal wiring. What kind or external disconnect would I need? Something like this:
https://www.homedepot.com/p/Eaton-200-Amp-Enclosed-2-Pole-Outdoor-Circuit-Breaker-ECCVH200R/205936221

As for the wire size and type, figuring on about 250' from the meter - along the house, around the septic and to the garage. What do you all recommend?
The route will be pretty much the blue line in the below picture:

 

[penright]

One thing I would throw out for thought. While the trench is open, along side the line voltage conduit lay in a low voltage one. The cost would not be that much and if someday you want to run internet, security cameras, tie into your home security, etc ...

I did it, my only regret, I used 1". I wished I would have went a size bigger. I had 360 degrees and little over 220 feet. Pulling wire that distance would have been a lot easier, if the conduit was a tick bigger.

 

[Aceman]

You will need to install a transfer switch at the house installed in front of the panel(s) you want generator backup on. Wired between the meterbase and existing panels. This would be your new service disconnect. All grounding electrode conductors would be rerouted here. All your grounds and neutrals in the panels downstream would have to be separated. If you have any older 3 wire SE cables using the neutral for bonding(oven, dryer), they would have to be replaced with a proper 4 wire cable.

You would then run power and controls from the proposed generator location to the transfer switch.

Adding a generator is not a small or cheap project in this regard.

It's easy when everything is getting installed in the beginning, but A LOT of work to retrofit later. Of course, with enough money, anything is possible.

 

[wyliesdiesels]

If a new service is out of budget, the required transfer switch wiring etc as detailed by aceman above will probably be as well.

 

[jpcjguy]

If a new service is out of budget, the required transfer switch will probably be as well.

can you elaborate? I had the electric company engineer come out to the house and he said I would be looking at 3000ish to run new service based on distance from the closest "green box"

 

[wyliesdiesels]

can you elaborate? I had the electric company engineer come out to the house and he said I would be looking at 3000ish to run new service based on distance from the closest "green box"

Did you read Aceman's comment above?

Pictures of all your panels with covers removed and meter base would be helpful!

 

[Norcal]

Adding a generator is not going to be cheap.

 

[jpcjguy]

Did you read Aceman's comment above?

Pictures of all your panels with covers removed and meter base would be helpful!

Sorry. Somehow I missed his comment. I read and replied to your comment off the email notification. I did not get an email from his post. Anyway, I appreciate the replies. Now I see that it sounds quite expensive. I will try and get some pics of the panels and meter, though.
if I drop the generator concept, what type of disconnect would I need? Would the one I linked to suffice?

Thanks
Joe

 

[jpcjguy]

So here is a pic of my panels

Here where I was thinking of the "disconnect" box and then the line down and around to the back of the house. It will run next to the slab of the garage and then under the house, ultimately coming out the corner and going to the garage

Another perspective of where the garage is going - where the shed is currently.

 

[ard]

A few comments:

Trenching "along the foundation" is a absolute total PITA. IMO, you want to trench AWAY from the foundation and get out 'into the open' as soon as you can. My preference. Get a big 4x4 ride on trencher and blow that puppy out in 2 hours.

I am also unclear on the overall power and service needs- you have "twin 200Amp panels in the garage" and need a THIRD 200A panel in the detached garage? Almost unbelievable.

I have a similar challenge on my place- with respect to a generator. Would like it at the shop, 300feet from the house. Have a 500G propane tank there already. Unfortunately the switching to be able to:

-disconnect the main service from the PoCo ;
- have the generator turn on,
- connect to the barn panel,
- then have the barn service backfeed up to the home (or a smaller subpanel at the home),

was never contemplated when I built. I suspect I would spend far more on the install (even DIYing) then the generator would cost. (Trenching, conduits, finished landscaping, driveways, interior walls, etc)

Oh, 250 ft of 200A wire. Have you run voltage drop calcs and priced this out? 125A may look much more 'adequate' once you do

Finally, your pictures are hosed. Did you upload them to GJ using the 'manage attachments' function? Easier.

 

[wyliesdiesels]

Pictures didnt load

 

[jpcjguy]

ARD - thanks for the comments. I am 100% electric at the house and well and septic. I don't think I would need 200A at the garage, just future proofing if I end up with upper and lower HVAC.
It does sound like the generator setup is going to be $$$$$ from what people have stated in this post. Thought it would smart to at least explore the option.
As for trenching away from the house - normally I would agree, but the problem is that the septic field is in the backyard and it would mean going a long way around - increasing length. Not to mention the retaining wall and slope I would have to deal with coming straight out from the house. Here is a pic that shows it.

The yellow orange and pink lines are the proposed route. The blue would be to avoid digging and after more looking at the house - a major PITA.
I reworked the links for the pics, so hopefully they are working now. let me know.

Thanks
Joe

 

[b-boy]

If it was me, I'd take the blue route.

 

[ard]

I assume the septic TANK is some distance away from the house and patio?

Cross the line feeding the tank before the septic 'field'. Should be a single ABS pipe.

 

[jpcjguy]

Here is a pic of the septic routing. This is why I am considering going the 26 feet next to the foundation and then under the house for 50ish feet and coming out the corner and following the orange line out to where the garage will go (shed is there now)

 

[ard]

no picture

this entire thread is devoid of pictures except the one 4 posts above....

 

[jpcjguy]

Apparently I am picture challenged. I apologize for the frustrating thread.

I have attached the pictures of the following:
electric panels
potential disconnect location next to meter
showing where the future garage location is relative to the meter (shed location)
current septic tank and field.

 

[wyliesdiesels]

Looking at your panels, you have a huge can of worms if youre gonna add a TS for a generator.

Both panels are fed with 3-wire SER with bonded neutral. This means they are both main service panels.

Adding a TS turns it into the main service panel for the service which means the 2 inside panels would need to be re-fed with new 4-wire SER, the neutral bar needs to be unbonded, a ground bar(s) need to be added and all grounds currently on neutral bar needs to be moved over to new ground bar(s).

Also, the GEC going to these panels needs to be moved to the TS.

If youre living in the house, this obviously means no power for the whole house for at least a day if not longer depending on PoCo and inspector schedules.

As I said, HUGE can o' worms...

 

[jpcjguy]

Looking at your panels, you have a huge can of worms if youre gonna add a TS for a generator.

Both panels are fed with 3-wire SER with bonded neutral. This means they are both main service panels.

Adding a TS turns it into the main service panel for the service which means the 2 inside panels would need to be re-fed with new 4-wire SER, the neutral bar needs to be unbonded, a ground bar(s) need to be added and all grounds currently on neutral bar needs to be moved over to new ground bar(s).

Also, the GEC going to these panels needs to be moved to the TS.

If youre living in the house, this obviously means no power for the whole house for at least a day if not longer depending on PoCo and inspector schedules.

As I said, HUGE can o' worms...

Wow. Great info. Appreciate it - not gonna do it. Glad I asked though.

So regarding the garage wire:
The largest breaker I can get for the panel is a 125. I talked to the building inspector and he agreed that I (not me personally) can tap into the meter directly and go to an external disconnect and then go along the side of the attached garage (buried next to slab) and then under the house and come out the corner and trench to the garage.
This would allow me to wire for a larger panel in the garage (another 200A perhaps?)
Was I close in the type of disconnect I need that I listed in the first post?

 

[wyliesdiesels]

How many sets of lugs does your meter pan have?

Probably only 2.

If thats the case, only other option is a tap off of one of the other feeders. Unless the lugs are rated for more than one wire which is very doubtful.

Does your meter panel have a tamper seal on it?

 

[Bert_]

Looking at your panels, you have a huge can of worms if youre gonna add a TS for a generator.

Both panels are fed with 3-wire SER with bonded neutral. This means they are both main service panels.

Adding a TS turns it into the main service panel for the service which means the 2 inside panels would need to be re-fed with new 4-wire SER, the neutral bar needs to be unbonded, a ground bar(s) need to be added and all grounds currently on neutral bar needs to be moved over to new ground bar(s).

Also, the GEC going to these panels needs to be moved to the TS.

If youre living in the house, this obviously means no power for the whole house for at least a day if not longer depending on PoCo and inspector schedules.

As I said, HUGE can o' worms...

If you put in a non fused transfer switch then you can run 3 wire.

 

[wyliesdiesels]

If you put in a non fused transfer switch then you can run 3 wire.

How so?

A disconnect is a disconnect.

Aceman and I are in agreement on this BTW. See #3....

 

[Norcal]

Wow. Great info. Appreciate it - not gonna do it. Glad I asked though.

So regarding the garage wire:
The largest breaker I can get for the panel is a 125. I talked to the building inspector and he agreed that I (not me personally) can tap into the meter directly and go to an external disconnect and then go along the side of the attached garage (buried next to slab) and then under the house and come out the corner and trench to the garage.
This would allow me to wire for a larger panel in the garage (another 200A perhaps?)
Was I close in the type of disconnect I need that I listed in the first post?

The largest breaker avail. may be 125A, but is the panel listed for larger then 100A? The label on a C-H panel of that vintage is in the box inside on the sidewall where it should be marked as to the maximum allowed per bus stab.

 

[brewchief]

Depending on how much voltage drop you can deal with it looks like you will need 250 mcm to 400 mcm wire, a quick check online has you spending 1200$-1500$ on wire, it may be cheaper locally or more expensive.
Add the cost of a disconnect, some conduit and fittings and possibly hiring an electrician to connect the disconnect at the meter base and you may end up very close to the power company price, don't forget to add the cost of a trencher rental as well.

Future proofing can get out of hand pretty easy.

Sent from my XT1254 using Tapatalk

 

[jpcjguy]

How many sets of lugs does your meter pan have?

Probably only 2.

If thats the case, only other option is a tap off of one of the other feeders. Unless the lugs are rated for more than one wire which is very doubtful.

Does your meter panel have a tamper seal on it?

I assume 2 also. I reached out to the power company for confirmation. It does have a tamper seal tag on it, so I cannot get into it.

 

[jpcjguy]

The largest breaker avail. may be 125A, but is the panel listed for larger then 100A? The label on a C-H panel of that vintage is in the box inside on the sidewall where it should be marked as to the maximum allowed per bus stab.

I took the cover off this morning and the panel is a CH30JJM200N. On the sticker it said " Branch finger rated at 140Amp Max". It that what you are talking about?

 

[jpcjguy]

Depending on how much voltage drop you can deal with it looks like you will need 250 mcm to 400 mcm wire, a quick check online has you spending 1200$-1500$ on wire, it may be cheaper locally or more expensive.
Add the cost of a disconnect, some conduit and fittings and possibly hiring an electrician to connect the disconnect at the meter base and you may end up very close to the power company price, don't forget to add the cost of a trencher rental as well.

Future proofing can get out of hand pretty easy.

Sent from my XT1254 using Tapatalk

I 100% agree. I know this will not be cheap. I am exploring my options and figure I will review what the costs are for 100A, 125A, 150A, 200A. Based on what I can "physically" do and then look at the incremental total costs as I go up in Amps, I figure then I can make a decision on how far I want to go.
For example, if the incremental costs to go from 125A to 200A is $500, that might be worth it (when looking net cost differential), if it is $1300 - that might not be.
Just trying to get a handle on what is possible and determine what is reasonable. One thing I have learned on this forum is to do your homework beforehand!!!!

Also, it appears that the generator transfer switch is way more $$$ than is worth it for me, based on general opinion on here.
The reality is we have lost power about 6 times in 4 years and the longest outage was about 7 hours with the average about 30min - 1 hour. (We also have my parents and my in-laws both within 30 minutes drive, so we always have a place to go with the kiddos)

 

[wyliesdiesels]

Instead of doing a whole house TS, you could do a branch circuit transfer switch that will run just the critical loads.

1 or 2 lighting circuits, fridges, freezers, well, septic internet/network eq. and TV...

 

[wes73]

Just an out of the box thought... How about adding an 'architectual feature' above you first floor windows and run your conduit behind that? No digging or pulling through crawl spaces

 

[jpcjguy]

So I reached out to the power company and the representative sent out a service guy to look at my meter base. He said that it can be done - adding a disconnect box to the left of the meter base. He would prefer it on the right since the lines come up the left side, but said it is doable (but tight).
So now i need to figure out the correct kind of outdoor disconnect box I need to get.

 

[jpcjguy]

Instead of doing a whole house TS, you could do a branch circuit transfer switch that will run just the critical loads.

1 or 2 lighting circuits, fridges, freezers, well, septic internet/network eq. and TV...

Agreed. I have a 8K running, 13.5K starting generator now that I use for the fridges. Just need to move the appropriate circuits to a smaller transfer switch for the essentials. The money spent on whole house is not worth dragging the generator from the shed to the driveway on rare occasion. Besides, the more work it takes me to setup for the generator just ensures the quicker I will get power back! Murphy's law!

 

[jpcjguy]

Just an out of the box thought... How about adding an 'architectual feature' above you first floor windows and run your conduit behind that? No digging or pulling through crawl spaces

Good thought but I don't think that will fly with the boss.

 

[ard]

Maybe first step is to nail down the cost, at least between 125 and 200?

125A:
#250 Aluminum
125A breaker
No external disconnect

200A
#400 Al
External Disconnect

Wiring cost delta = ???
DIY versus Electrician = ???
125A breaker versus Exterior Disconnect piped into main meter = ???

Cost of a 125 vs 200 main panel in the garage is a push

Guys, do I have this right?

 

[Bert_]

How so?

A disconnect is a disconnect.

Aceman and I are in agreement on this BTW. See #3....

By NEC definition a service disconnect has over current protection. So a transfer switch without a breaker or fuse is not a service disconnect and you don't have to separate neutral and ground.

I run three wire all the time after poletop and grade level switches. No fuses, no problem.

 

[wyliesdiesels]

By NEC definition a service disconnect has over current protection. So a transfer switch without a breaker or fuse is not a service disconnect and you don't have to separate neutral and ground.

I run three wire all the time after poletop and grade level switches. No fuses, no problem.

I looked in article 100 definitions and did not see a definition for that. Maybe i missed it...

And a transfer switch placed between meter pan and existing main service panel becomes the main disconnect.

And if youre referring to utility switchgear, that has no bearing on this.

 

[Norcal]

I took the cover off this morning and the panel is a CH30JJM200N. On the sticker it said " Branch finger rated at 140Amp Max". It that what you are talking about?

Yes, that means the largest breaker opposite the 125A is a 15A.

 

[jpcjguy]

Yes, that means the largest breaker opposite the 125A is a 15A.

Interesting - I did not know there were restrictions in the size of breakers opposite each other in the panel - good to know! thanks!

 

[jpcjguy]

Maybe first step is to nail down the cost, at least between 125 and 200?

125A:
#250 Aluminum
125A breaker
No external disconnect

200A
#400 Al
External Disconnect

Wiring cost delta = ???
DIY versus Electrician = ???
125A breaker versus Exterior Disconnect piped into main meter = ???

Cost of a 125 vs 200 main panel in the garage is a push

Guys, do I have this right?

ard - this is exactly what I am trying to do! I figure the conduit is a "push" between the two. The 200A would probably be bigger but I would think the incremental from say 2" to 2.5" would be not too much in the grand total.

Can anyone let me know if I am on the right track for the disconnect box? Is there anything special I need to be looking for?

 

[Bert_]

I looked in article 100 definitions and did not see a definition for that. Maybe i missed it...

And a transfer switch placed between meter pan and existing main service panel becomes the main disconnect.

Ehh my bad on the wording, "service equipment" is the definition I was thinking of. Same logic applies.

And if youre referring to utility switchgear, that has no bearing on this.

No this is often customer owned equipment. Ronk makes a lot of popular equipment like this.

 

[jpcjguy]

So after some more "house planning", my stick built 2 story 36x30 garage probably just became a 40x30 pole building..... Somehow I got cornered by the family about a pool, which means the garage just got a lot "simpler".
Not that I mind, the family will enjoy the pool a lot more than just me in the garage.

So on that note I am revisiting my electrical needs. I did go to the county and talked to an inspector and he said that if I have a 200A external disconnect for the garage, I need two more (1 for each existing 200A panel in the attached garage). That definitely increases the cost and complexity - let alone the "wall" of gray boxes on the side of the house garage!

So I am rethinking about going to a 125A in one of my existing panels in the garage. The 125A should be more than enough for my welder (miller 252), 60 gallon compressor (just a simple husky brand), potential plasma, future 10k lift, full size fridge, lights, tools etc. This is on the premise that 90% it is just me out there and therefore only one thing running at a time. However I do have to think about the future - I have twin 8 year old boys that I hope will join me out there one day!

My wild card is heat and AC down the road. Right now the house is 100% electric - so no gas anywhere. I am not opposed to doing a propane tank behind the garage and doing a vented heater so I am not using a ton of electricity for heat in the winter. The building will be 100% insulated before I HVAC it.
How about air conditioning? How do I calculate the power needs for a 40x30x12?
Will 125A be enough for future proofing for HVAC - if I do not have electric heat and go propane?
What factors am I not thinking about?

Thanks!