200amp service at a long distance

[DaveInTX]

I'm just thinking out loud here, so bear with me... So a new 200amp service requires 2/0 copper or 4/0 aluminum - but if this 200amp service is about 150' away from the PoCo meter, I would probably need to upgrade to 3/0 copper to account for voltage drop, right?

Only issue with this I've seen, is most of the 200amp panels, at least the GE ones that I'm familiar with (the brand that was installed on our house) only handle up to 2/0 wire at the lugs. Are there are adapters to step-down from a 3/0 wire to a 2/0 lug? Is this allowed? Or would I need to source a panel larger than 200amp to accommodate the 3/0 wire? Thoughts?

 

[alfredeneuman]

Are you sure that isn't the minimum size of the lug?
All panel's (and breaker's) lugs accomodate the maximum expected wire sizes

 

[wyliesdiesels]

pin terminals

 

[jeepxj]

pin terminals

you use offset pin's or just the straight in ones?

 

[Bert_]

I don't know any 200a panels with 2/0 max lugs. Most will do 300MCM, 250 for sure.

I wouldn't get too worried about voltage drop at only 150'

 

[sparky 1971]

Square D 200 amp mains can take up to 250 mcm, I'm sure other brands are the same. 150' is nothing to be concerned about for a 200 amp service. Mine's about that far and I didn't give voltage drop a second thought.

The current GE catalog shows all 200 amp main breakers accepting at least a 250 and a couple that will take a 300.

 

[DaveInTX]

Thanks all! I must've been misreading the GE tech specs - looking at them now, I can see that the GE specs do say 250 mcm - not sure where I was reading the 2/0...

That is good to hear that the general consensus is that voltage drop isn't a huge concern at that distance. Ideally I'd be able to run 2/0 cable to avoid the price increase at 3/0.

 

[sparky 1971]

Thanks all! I must've been misreading the GE tech specs - looking at them now, I can see that the GE specs do say 250 mcm - not sure where I was reading the 2/0...

That is good to hear that the general consensus is that voltage drop isn't a huge concern at that distance. Ideally I'd be able to run 2/0 cable to avoid the price increase at 3/0.

Why not use 4/0 aluminum?

 

[theoldwizard1]

Is this for a garage/shop ? I can not imagine the need for 200A service unless you are planning on inviting a bunch of buddies over for a welding party. Just because the panel says it is 200A does not mean you need to FEED it with 200A. Worst case would be tripping the breaker that feeds the wire.

A one man operation can get buy with 100A. Even 60A will run a welder and a mini-split. You might have to turn off the A/C if you are using a plasma cutter.

 

[mike93lx]

Have you priced out that 2/0 copper and compared it to 4/0 aluminum? Copper will be about double. If you have a disconnect at the meter, that means a 4 wire feed.

That's a huge amount of extra spend for no gain other than slightly smaller wire

 

[mcbane]

200 amps, 150' run, 4/0 aluminum is only 2.7% voltage drop for a 240 volt circuit. And even if you one of the GJ people with 220 volt power, would be only 3% voltage drop.

And as a practical matter, feeders are almost never running at full current so typical voltage drops would be far less. If you want to avoid voltage drops at sensitive tools your money is better spent selectively upsizing longer branch circuit conductors.

 

[u2slow]

I'd run 250kcmil alum if you anticipate max capacity out there. Fits in any 200A residential panel lugs in my experience.

Would be direct-burial cable for me. If doing conduit, consider the length of the run and probably needs to be oversized to pull in easy.

 

[Norcal]

The OP has not specified what the service is for, & 4/0 AL, or 2/0 CU, is for dwelling services, for other applications if the load is 180A or less then the next standard size up of fuse or circuit breaker can be used.

 

[DaveInTX]

Thanks all for the comments! My first post was (intentionally) a bit vague - maybe I can shed a bit more light. I'm putting in a new shop about 100' from my house, and exploring what my options are for getting power to it.

Currently, my electric meter (200 amp service) is installed on my house - it's fed by an aerial cable from a pole-mounted transformer ~125' away. From what I can tell, I have two options to get power to the shop (shown in the picture).

Option A - run new cable (underground, thinking MHF) from my existing house-mounted breaker panel to the shop. I think 100 amp would be more than adequate. Problem is, the breaker panel and subpanel next to it are already very full. I could potentially replace the subpanel with a larger one, and then run my new 100amp wire from there.

Option B - move my electric meter back to the utility pole - my PoCo doesn't have any issue with this. From there, I'd run 200 amp service (underground) to the shop, and then feed-through 200 amp service (underground) to the house. In this scenario, the intent with feeding from the shop to the house (rather than from the house to the shop) is so that I can install a generator + transfer switch at the shop, and then power the house in the event of an outage. I'm thinking this would involve running 4/0 aluminum (or 2/0 copper) from the pole -> shop -> house. I'd also have to split the grounds and neutrals in the house panel, since it'd be converted a subpanel.

Option A seems more realistic - the main downsides being 1) have to figure out some way to fit the 100amp wires in the existing breaker panel, 2) I can't feed the house from a generator located at the shop (not a deal-breaker), and 3) we were going to use this as an excuse to take our aerial cable underground (which Option B would've done).

Option B seems more expensive (especially if I have to use copper), and problematic if I can't fit 4/0 aluminum in the lugs of my current panel.

Some might say "add another electric meter to the shop, and just run a new leg from the pole to the shop" - I'm trying to avoid this, as the PoCo charges per meter per month.

This may seem confusing given my original post - in my head, my original post was based on the idea of using 2/0 copper for "Option B", under the assumption that 4/0 (aluminum) wire doesn't fit in my existing breaker panel.

Now that you know the "full" story, I'm very curious to your opinions on this. Thanks!

 

[mike93lx]

You could do a and run a feed from the generator back to the transfer switch at the house. It's extra wire, but doable

You can't install a couple tandems to free up two spaces for the breaker to feed the shop?

 

[DaveInTX]

You could do a and run a feed from the generator back to the transfer switch at the house. It's extra wire, but doable

You can't install a couple tandems to free up two spaces for the breaker to feed the shop?

Thanks Mike! You know, I didn't think about that (running a second line)... I'll dig into it and see if it makes sense with my application.

And my panel is already pretty full of tandem and 1/2" breakers, so there's not much room to spare. There are a couple full-size breakers left, but those are feeding other subpanels around the house.

 

[jeepxj]

90a is far cheaper to put in than 100a.

if you have 2 240v circuits use a quad and free up space for the 90/etc garage feed.

 

[mike93lx]

Thanks Mike! You know, I didn't think about that (running a second line)... I'll dig into it and see if it makes sense with my application.

And my panel is already pretty full of tandem and 1/2" breakers, so there's not much room to spare. There are a couple full-size breakers left, but those are feeding other subpanels around the house.

Subs can be fed from tandems, just need a handle-tied quad like @jeepxj is showing.

Although it may be a good opportunity to think about some rework if things are getting messy from the complexity

 

[AP514]

Copper Wire for the WIN.....After 20 years Alum goes to ****...at least in the rentals I have.

 

[mike93lx]

Copper Wire for the WIN.....After 20 years Alum goes to ****...at least in the rentals I have.

The stuff today isn't the **** of the past. Aluminum is safe. And a lot cheaper

 

[Norcal]

Copper Wire for the WIN.....After 20 years Alum goes to ****...at least in the rentals I have.

Need to start hiring competent people that know what they are doing, nothing wrong with aluminum alloy conductors.

 

[theoldwizard1]

Duplicate

 

[theoldwizard1]

90a is far cheaper to put in than 100a.

if you have 2 240v circuits use a quad and free up space for the 90/etc garage feed.

Concur !

 

[Bert_]

Copper Wire for the WIN.....After 20 years Alum goes to ****...at least in the rentals I have.

I see lots of aluminum wire dating back as far as the 70's. Very few problems...

 

[wyliesdiesels]

Copper Wire for the WIN.....After 20 years Alum goes to ****...at least in the rentals I have.

ive seen aluminum wire way older than 20yrs and it hasnt gone to **** so im not sure what youre talking about

 

[mike93lx]

ive seen aluminum wire way older than 20yrs and it hasnt gone to **** so im not sure what youre talking about

Like nearly every feeder wire hanging on a pole in the street?

 

[wyliesdiesels]

Like nearly every feeder wire hanging on a pole in the street?

different alloys but same concept

 

[DaveInTX]

Thanks for the responses all!

Subs can be fed from tandems, just need a handle-tied quad like @jeepxj is showing.

Although it may be a good opportunity to think about some rework if things are getting messy from the complexity

Your comment there is kind of why I'm leaning towards "Option B" (i.e. moving the meter back to the utility pole and running new wire from the pole -> shop -> house). It will be a bit more $$ up front, but I could definitely use some space in my breaker panel, and it'll give me the option of feeding the house from a shop-located generator.

With the all-in price-per-foot, it (surprisingly) almost makes sense to run separate 2/0-2/0-2/0-4 copper THHN/THWN-2 wires, versus 4/0-4/0-4/0-2/0 Aluminum MHF.

 

[mike93lx]

With the all-in price-per-foot, it (surprisingly) almost makes sense to run separate 2/0-2/0-2/0-4 copper THHN/THWN-2 wires, versus 4/0-4/0-4/0-2/0 Aluminum MHF.

Huh? 2/0 copper is about $4-5 a foot, each. The entire 4/0 MHF is $10. Plus the THWN requires conduit, while the mhf doesn't .

If you are running conduit, use aluminum xhhw. Your four conductors will be under $9 a foot, total.

It's your money, but mine would be buying aluminum at that size

 

[DaveInTX]

Valid point, and I appreciate the insight. I was planning on running conduit, regardless of using aluminum or copper wiring. If I run the copper (2/0), it looks like I can get by with 1.5" conduit; if I go with aluminum (4/0), I'll have to bump up to 2" conduit (per the Southwire conduit fill calculator - I'm open to recommendations though if anyone has any). It's not a huge deal, but 1.5" will probably save me $8 or so per 10' stick.

I've found 2/0 THHN/THWN-2 locally for $2.84/ft - that's why I was leaning towards copper. For the four wires, it's right around $10/ft. But I didn't think about the aluminum XHHW, so that is another option on the table...

 

[rharman]

90a is far cheaper to put in than 100a.

if you have 2 240v circuits use a quad and free up space for the 90/etc garage feed.

Not to hijack the OP's thread but curious....

Is the quad two independent 240V breakers? Meaning that the inner & outer handle pairs are NOT tied to each other?
I have this in my panel and I assume it's for our pair of A/C compressors (label is really faded).

Thanks!

 

[wyliesdiesels]

Not to hijack the OP's thread but curious....

Is the quad two independent 240V breakers? Meaning that the inner & outer handle pairs are NOT tied to each other?
I have this in my panel and I assume it's for our pair of A/C compressors (label is really faded).

Thanks!

yes

 

[mike93lx]

Valid point, and I appreciate the insight. I was planning on running conduit, regardless of using aluminum or copper wiring. If I run the copper (2/0), it looks like I can get by with 1.5" conduit; if I go with aluminum (4/0), I'll have to bump up to 2" conduit (per the Southwire conduit fill calculator - I'm open to recommendations though if anyone has any). It's not a huge deal, but 1.5" will probably save me $8 or so per 10' stick.

I've found 2/0 THHN/THWN-2 locally for $2.84/ft - that's why I was leaning towards copper. For the four wires, it's right around $10/ft. But I didn't think about the aluminum XHHW, so that is another option on the table...

That's a good deal for 2/0 copper. Yeah, check them for the AL and if it isn't materially cheaper, copper is the smart play.
.that is going to be a hell of a pull through 1.5". The entire time, you will be wondering why you didn't spend the extra couple hundred for 2"...


Do 2". Use lots of lube and get two friends to help.